WATER IS NOT JUST MADE OF H2O IT HAS AN UNEXPLORED THIRD ELEMENT WHICH IS GOING TO LITERALLY REVOLUTIONALISE THE ENERGY PROBLEM AND THIS HAS TO BE DISCOVERED ONLY USING APPROPRIATE TECHNOLOGY AND FINDING THE CORRECT CHEMICALS THAT MAKE UP WATER WILL REVOLUTIONISE THE FUTURE OF LIFE AND ALSO SOLVE THE ENERGY PROBLEM OF HUMANITY.
THIS SHOULD NOT BE PATENTED. IMAGINE THE PLIGHT OF THE WORLD HAD MADAME CURIE PATENTED HER DISCOVERIES.
SO PLEASE LET ALL THE SCIENTISTS OF THE WORLD COME FORWARD AND WORK TOWARDS THIS.
I HAVE DECIDED TO BRING THIS UNEXPLORED POTENTIAL OF WATER WHICH I HAVE KEPT IN THE ATTIC OF MY BRAINS FOR ALMOST 20 PLUS YEARS INTO THE OPEN THROUGH THIS BLOG. LET US ALL WORK TOGETHER AND BRING OUT THE NEXT SOURCE OF ENERGY FOR THE WORLD.
In fact to tell you the truth, this obsession with water has been there since my school days. Only to do something or learn something on this I became the secretary of the science club in Sri Ramakrishna high school in 1975 when I was in my tenth standard but when I asked the teachers none of them were able to give any proper reply. In those days as internet was not there, culling out reference and reading materials were a bit difficult. However as my father was a very versatile and multifaceted academician in the sixties and early seventies when he was at Karur, which was purely undeveloped village in those days I mean up to the 70s, he used to travel to Trichy to get UK BASED MAGAZINE called Understanding Science WHICH HAD VERY GOOD PICTURES AND LOTS OF EXPERIMENTS IN SCIENCE. In one of the issues there was an experiment titled Chemical garden, which I did with lot of enthusiasm. Then it again struck to me while there was so much of praise from others [ for that chemical garden] and pride in me for having done that, I reflected for a while on that day itself and wondered how silently water has been maintaining and making rich the whole garden of earth as a part of nature. This made me hunt for all sorts of books on water and water related subjects from British Council Library. However as I was a commence student by academic qualifications and a linguist and musician by passion I was not entertained in any institute of science or even by professors of science for two reasons I was not qualified to ask questions to do a research without basic qualification as at least a degree holder in science and because I was asking about something which was not in their usual syllabus. However this never stopped my Love for water [even physically from my fourth year all my brothers and parents have found it difficult to get me out of the Amaravathi river at Karur] So, in 2003 when UN declared it as a year of water I renewed my old romance with water to hunt for reference materials on water. I scanned the net but I could not get what I wanted. However I did not want the materials I gathered from the net to go waste, hence I made a water diary for 365 days with all sorts of information for school students. I am enclosing the rough draft, which is the only thing I have now in my system, which will educate the students about all aspects of water from science to politics.
You may if you deem fit forward this letter along with the attachments to your friends just to make them know that a fire of passion which has kindle the interest in water will definitely find something one day to help humanity. Whenever or wherever any idea crops it is the will of divine spirit that it must deliver the ultimate [not final because there is no final to anything only ultimate] result or purpose for which it has emanated. In this particular case I think it is to discover the unexplored aspects of immense potential that water has for this planet as a whole, not only humanity.
BALAYOGI
18 comments:
so from today i shall post in parts the water diary i prepared in 2003 for the UN year of water. most the material has been taken from several sources. since i don't have a record of the sources as well as they are too many in number i am not able to thank everyone individually so instead i would like to place on record my sincere thanks and gratitude to all those whose materials have been used here for purely academic reasons.
Preface
Water is needed in all aspects of life. The general objective is to make certain that adequate supplies of water of good quality are maintained for the entire population of this planet, while preserving the hydrological, biological and chemical functions of ecosystems, adapting human activities within the capacity limits of nature and combating vectors of water-related diseases.
--Agenda 21, endorsed by leaders of 178 nations at the 1992 United Nations Conference on Environment and Development in Rio de Janeiro
Difficult to purify, expensive to transport and impossible to substitute, water is essential to food production, to economic development and to life itself
Water covers almost ¾ of the earth’s total surface (146 million square miles or 379 million square kilometers) Water makes earth the “blue” planet, visually unique from all others in the solar system
On a planet whose surface is more than two thirds covered by water, the illusion of abundance has clouded the reality that renewable fresh water is an increasingly scarce commodity.
While the world's oceans may seem unbounded, the amount of fresh water actually available to people is finite—
Resource scarcity can exacerbate pre-existing tensions or invite new ones, and water is no exception.
The finite nature of renewable fresh water makes it a critical natural resource to examine in the context of population growth. Few other resources so essential to daily life are bounded by such fixed limits on supply--limits that in dozens of countries are already constraining efforts to improve health and living standards
The reality is that there is essentially no more fresh water on the planet today than there was 2,000 years ago when the earth's human population was less than three percent its current size of 5.5 billion people.
As population grows, the average amount of renewable fresh water available to each person declines. Hydrologists and other water experts agree that when certain ratios of human numbers to renewable fresh water supplies are exceeded, water stress and outright scarcity are all but inevitable Life is tied to water as it is tied to air and food. And food is tied to water since plant growth depends on its flow from roots to foliage. Throughout history, secure access to water has been essential to social and economic development and the stability of cultures and civilizations. Since ancient times agriculture has depended on fortuitous combinations of good soils and predictable water supplies, and dependable sources of abundant water played a prominent role in the industrialization of Europe and North America. Even if less developed nations pursue new development paths that avoid the errors of the past, it is difficult to imagine how sustainable development will proceed if renewable fresh water is in short supply.
Population growth not only increases human water needs, it also helps accelerate environmental disturbances of the water cycle as a by-product of the greater production of food and fuel. Among these disturbances are deforestation and other destructive land use practices, the disposal of waste, the use of pesticides and fertilizers, and the release of greenhouse gases that could warm global climate. Many of these activities pollute the water that is available, in addition to limiting the amounts that can be captured There is nothing inherently unsustainable about the use of groundwater per se; people have been drawing water from wells since the earliest civilizations of the Fertile Crescent. But to ensure that wells provide as generously next year, or next century, water must be drawn at a rate that permits water table levels to remain stable over time. The rate of sustainable water use is determined not by human needs but by the laws of nature.
The risk of substantial changes in climate over the coming decades, coupled with the other threats posed by growing human pressures, underlines the uncertainty about future water supply--and the need for cautious, flexible and innovative planning.
It is important to recognize that water can be withdrawn and used without being consumed. Water that irrigates a field can flow back into the river--with losses from evaporation and crop intake and some decline in quality--and drawn again downstream to irrigate another field. In contrast, water that is consumed, such as drinking water, cannot be recycled (without expensive treatment) for subsequent human use. The distinction can be important, because in some countries water withdrawals already exceed water supply, while water consumption does not. Where hydrologists speak of water use, they generally mean withdrawals.
Though there have been so many useful and expert methods enacted and experimented to ensure that natural resources and environment are protected in tact for posterity. In this year all the member nations of UN must insist on forming a body of representatives[non political] from all the countries of the world who just need to function from their respective places and ensure to monitor the activities in terms of usage of natural resources and every year there can be one or two meeting in some chosen country and all the members here must have equal rights there must not be any preferred status for any nation on any account then the very status of international monitoring and management will become questionable. We all must realize that natural resources are for human beings living all over the globe. In commerce we have reaped the benefits of globalization but why haven’t we ever thought of globalization of natural resources. There must be a global audit on at least water usage to start with where by all the countries must be required /allotted only water usage proportionate to the land area of the country. only then countries that do not check population growth very effectively like India and China will realize the impact of population and also countries like USA which use enormous amounts of natural resources per person will also develop some global social and environmental respect. Natural resources can neither be allowed to be misused as is done in India where there is utter neglect because of massive rivers, nor allowed to be over used because of
affordability ,availability or affluence as is done by USA.
1] What is water?
Water is a colorless, tasteless, and odorless liquid at room temperature. Water may appear in nature in three states: a liquid, a solid and a gas (vapor). Below freezing water, is a solid (ice or snowflakes), between freezing and boiling water is a liquid, and above its boiling point water is a gas. Water changing from a solid to a liquid is said to be melting. When it changes from a liquid to a gas, it is evaporating. Water changing from a gas to a liquid is called condensation. An example is the 'dew' that forms on the outside of a glass of cold soda. Frost occurs when water changes from a gas directly to a solid form. When water changes directly from solid to a gas, the process is called sublimation.
2] The water molecule
is composed of the elements Hydrogen and Oxygen. Both Oxygen and Hydrogen atoms combine to form a v-shaped molecule. This v-shaped molecule as a whole is electrically neutral, yet the oxygen atom holds a small negative charge and the two hydrogen atoms hold small positive charges. These properties makes water a unique substance.
Scientists believe this unusual electrical balancing, called polarity, gives water some of its remarkable properties. For example, scientists often call water the universal solvent because water can dissolve more substances than any other liquid.
3] Why is water the universal solvent?
§ First, water molecules are very small and move easily around other atoms and molecules.
§ Second, the negative charge on the oxygen atom and positive charges on the hydrogen atoms allow water molecules to interact with other molecules.
Third, water is very stable. At 2000C or 3632F, only about 2% of water molecules break into parts.
These parts are a positive H ion and a negative hydroxyl ion. Another very interesting and important property of water is its high specific heat capacity. This means it takes a lot of energy to raise the temperature of water. The specific heat of water is 5 times greater than the specific heat of sand. On a hot summer day, beach sand may quickly warm to the point that it’s too hot to stand on, while ocean water warms only a little.
4] The structure of water
For most substances, solids are more dense than liquids. This is not true for water. Water is less dense as a solid – ice floats on liquid water! Strong hydrogen bonds formed at freezing lock water molecules away from each other. When ice melts, the structure collapses and molecules move closer together. This property plays an important role in lake and ocean ecosystems. Floating ice often insulates and protects animals and plants living in the water below.
5] Water's Physical Properties
· Water is unique in that it is the only natural substance that is found in all three states -- liquid, solid (ice), and gas (steam) -- at the temperatures normally found on Earth. Earth's water is constantly interacting, changing, and in movement.
· Water freezes at 32o Fahrenheit (F) and boils at 212o F (at sea level, but 186.4° at 14,000 feet). In fact, water's freezing and boiling points are the baseline with which temperature is measured: 0o on the Celsius scale is water's freezing point, and 100o is water's boiling point. Water is unusual in that the solid form, ice, is less dense than the liquid form, which is why ice floats.
· Water has a high specific heat index. This means that water can absorb a lot of heat before it begins to get hot. This is why water is valuable to industries and in your car's radiator as a coolant. The high specific heat index of water also helps regulate the rate at which air changes temperature, which is why the temperature change between seasons is gradual rather than sudden, especially near the oceans.
· Water has a very high surface tension. In other words, water is sticky and elastic, and tends to clump together in drops rather than spread out in a thin film. Surface tension is responsible for capillary action, which allows water (and its dissolved substances) to move through the roots of plants and through the tiny blood vessels in our bodies.
· Here's a quick rundown of some of water's properties:
o Weight: 62.416 pounds per cubic foot at 32°F
o Weight: 61.998 pounds per cubic foot at 100°F
o Weight: 8.33 pounds/gallon, 0.036 pounds/cubic inch
o Density: 1 gram per cubic centimeter (cc) at 39.2°F, 0.95865 gram per cc at 212°F
By the way:
1 gallon = 4 quarts = 8 pints = 128 ounces = 231 cubic inches
1 liter = 0.2642 gallons = 1.0568 quart = 61.02 cubic inches
1 million gallons = 3.069 acre-feet = 133,685.64 cubic feet
The physical and chemical properties of water are extraordinarily complicated and incompletely understood
The Chemistry of Water Properties
Professor Jill Granger
Water is Weird !?
Chemically speaking, water is very weird. It doesn't behave at all like it should. Let's consider somethings you know:
Ice Floats. That's not weird.... is it?
That's very weird. The solid state of most things are much denser than the liquid state and therefore sink. Usually what happens when a solid is formed is that the molecules become more tightly packed together. When things melt, the molecules move apart and get liquid. But water is weird - the solid state is less dense than the liquid. To understand why we'll have to take a close-up look at the molecular arrangement of solid water (ice) and liquid water.
The Structure of Ice
IMAGE SOURCE: "Biochemistry", second edition, by D. Voet and J.G. Voet, John Wiley and Sons, Somerset NJ, 1995, Chapter 2 "Aqueous Solutions", pg 31
Water boils at 100°C
and freezes at 0°C.
That's certainly not unusual.
Oh, Yes it is! Did you know that the Celcius temperature scale was based on the two physical changes of water? That wasn't done because water has typical chemical behavior, only because water is a familiar substance. You may have realized too that the boiling point of water is not always "100 °C". Ever read Cake Mix Directions? They give different directions for "High Altitudes". That's because many physical changes depend on pressure. The boiling point of water depends on the pressure of the air around it:
Let's compare the boiling of water with some other chemically similar substances.
IMAGE SOURCE: "Chemistry in Context" Wm C Brown Publishers, Dubuque Iowa, 2nd edition, A project of the American Chemical Society, ed: A. Truman Schwartz et al., 1997, Chapter 5 "The Wonder of Water"
Water is way out of line! It boils at an extremely high temperature for its size. Why? Because of the extensive network of Hydrogen bonds. Those H-bonds are cohesive forces - they want to hold the water molecules together - and there are a lot of them! The process of boiling requires that the molecules come apart: a process that takes a lot more energy than expected.
What's unusual about the freezing point?
The freezing point is much higher than expected again because of the hydrogen bonding. To get the water molecules to undergo the transition from liquid to solid is relatively easy. Liquid water has only 15 percent more H-bonds than solid water. How am I affected by these temperature - phase relationships?
If water were "normal", it would be a gas at room temperature. No lakes, no rain, no body fluids!
Is there anything else?
Another result of the Hydrogen bonding network is that water has a very high Specific Heat. This is like the baked potato effect. Once heated, water takes a very long time to cool off. Or in reverse, it takes a lot of heat to make water hot. Compare the specific heat of water to some other common substances:
You've noticed and used water's high heat capacity yourself.
6] The Chemistry of Water
Professor Jill Granger
The Hydrogen and Oxygen of Water
Hydrogen + Oxygen = Water
The simple statement that water is made from hydrogen and oxygen doesn't give us a very clear picture of what really goes into the creation of a molecule of water. A quick look at the chemical equation for the formation of water tells us more.
2H2 + O2 = 2H2O It takes two molecules of the diatomic hydrogen gas, combined with one molecule of the diatomic oxygen gas to produce two molecules of water. In other words the ratio of hydrogen to oxygen is 2:1, the ratio of hydrogen to water is 1:1, and the ratio of oxygen to water is 1:2.
There's something more though that doesn't show up in the equation. Energy. The formation of water from it's elements produces, in addition to water, a tremendous amount of energy, 572 kJ to be exact.
2H2 + O2 = 2H2O + ENERGY
This is an example of an exothermic reaction, a reaction that produces energy. It is also an example of what is called a combustion reaction, where a substance (in this case hydrogen gas) is combined with oxygen. You are probably familiar with this reaction through two tragic examples of the unleashed energy of the combustion reaction of hydrogen, the Hindenburg, and the space shuttle Challenger.
Hydrogen Fuel?
Yes - hydrogen is a good, clean fuel, producing only water as a by-product. Unfortunately it produces so much energy that it can get out of control, resulting in an explosion. But let's forget about that explosive part for a minute and think about the possibilities - Hydrogen as a New Clean Fuel - it could be the end of the energy crisis - but where would we get the hydrogen?
Can we create Hydrogen from Water?
Oh Yes! It's the same chemical reaction, but run in reverse:
2H2O + ENERGY = 2H2 + O2
Notice now that the requirement is for energy to be ADDED TO the reactants. This is an example of an Endothermic reaction. This means that we could use Water as a Fuel! IF (and this is a big if) we could find an easy way to convert the water to hydrogen and oxygen, then the hydrogen could be used as a clean fuel.
One way to convert Water to Hydrogen and Oxygen is through the process of Electrolysis- using electricity as the source of energy to drive the reaction. Let's take a look at what that might look like:
IMAGE SOURCE: "Chemistry in Context" Wm C Brown Publishers, Dubuque Iowa, 2nd edition, A project of the American Chemical Society, ed: A. Truman Schwartz et al., 1997, Chapter 5 "The Wonder of Water"
Isn't this rather circular?
Using Energy to break water to form hydrogen to combine oxygen to
form Energy - in this way is rather circular. In fact, because of the laws of thermodynamics, you can't break even in this exchange of energy. However, there exist better ways to disassemble water - namely using CATALYSIS.
IMAGE SOURCE: "Chemistry in Context" Wm C Brown Publishers, Dubuque Iowa, 2nd edition, A project of the American Chemical Society, ed: A. Truman Schwartz et al., 1997, Chapter 5 "The Wonder of Water
What does a catalyst do?
A catalyst is a chemical compound that acts to speed up a reaction, but in the process is not itself changed. Therefore the catalyst, at the end of the reaction, is free to act again to assist another reactant through the reaction.
Catalysts work by lowering the energy barrier between the reactants and the products. In this case:
2H2O + ENERGY = 2H2 + O2
where it normally takes a tremendous amount of energy to convert reactants to products - the addition of a catalyst can decrease the amount of energy required and therefore speed the reaction up!
2H2O + CATALYST+ energy = 2H2 + O2 + CATALYST
Does this catalyst really exist?
Sort of...... Have you ever wondered how a plant uses water and carbon dioxide to create glucose and oxygen? This too is an endothermic reaction, an energy producing reaction run in reverse. Normally we would think of using glucose as a fuel, through oxidation we could produce carbon dioxide, water and energy - In fact this is what OUR bodies do to provide us with the energy we need for maintaining all of our bodily functions including THINKING!
Glucose (C6H12O6) + Oxygen (O2) = Water (H20) + Carbon Dioxide (CO2) + ENERGY
To run the reaction in reverse, the plant utilizes a catalyst - CHLOROPHYLL - and the energy from the SUN to aid in the decomposition of water. While the chlorophyllic reaction does produce diatomic oxygen gas, it does not produce the hydrogen in a gaseous form. The hydrogen released from the water is used for the formation of glucose.
Could we use such a catalyst for converting Water and Sunlight into Fuel?
Scientists often use Nature as a model for the development of new compounds. One such development, which has been studied extensively in this regard, is a molecule known as Rubippy. The structure of Rubippy is shown below. It is similar in structure to the chlorophyll molecule having a metal center (in chlorophyll it's a magnesium ion, in rubippy it's a ruthenium ion) and an attached system of organic rings (in chlorophyll its a porphyrin derivative, in rubippy its a pyridine derivative).
IMAGE SOURCE: "Chemistry in Context" Wm C Brown Publishers, Dubuque Iowa, 2nd edition, A project of the American Chemical Society, ed: A. Truman Schwartz et al., 1997, Chapter 5 "The Wonder of Water"
Acting as "relay" channel for the transfer of electrons, Rubippy has shown some potential to do just that - convert water and sunlight into a clean, seemingly inexhaustible, source of energy. However, while rubippy has shown promise in this regard, it is not a commercially viable enterprise because of it's high cost, instability, and low efficiency.
If Scientists were able to get Rubippy to work, or created a viable alternative, what would we do about the explosion potential of using Hydrogen Fuel?
Good question! Would you believe that it is possible to do the combustion of hydrogen without letting the oxygen and hydrogen come in contact? This can happen in a FUEL CELL. A fuel cell is like a battery- It utilizes a chemical reaction to produce electricity. A drawing of a hydrogen-oxygen fuel cell is shown below:
IMAGE SOURCE: "Chemistry in Context" Wm C Brown Publishers, Dubuque Iowa, 2nd edition, A project of the American Chemical Society, ed: A. Truman Schwartz et al., 1997, Chapter 5 "The Wonder of Water"
The kind of fuel cell shown here are routinely used in the space program. If this technology ever becomes viably available to the common person, the estimated cost of a fuel-cell hydrogen powered car would be less than half that of your current gas-mobile. In addition, it would be simpler, require less maintenance, and be environmentally friendly!
7] The Chemistry of Water
Professor Jill Granger
Structure Means Function
Water is a Chemical!?
Indeed! Water is one of our most plentiful chemicals. Its chemical formula, H20, is probably the most well known of all chemical formulas. What does the chemical formula tell us?
The formula H20 tells us that one molecule of water is comprised of 2 atoms of hydrogen and one atom of oxygen bonded together. The bonds which hold the hydrogen and oxygen together are called covalent bonds - they are very strong.
Let's look at a picture of a molecule of water: In this picture the two hydrogens are represented by white spheres and the oxygen by a red sphere.
IMAGE SOURCE: "Chemistry and Life", 4th Edition, John W. Hill, Dorothy M. Feigl, and Stuart J. Baum, Macmillan Publishing Company, New York, 1993
In this second picture, the hydrogens are shown as white spheres, the oygen as a red sphere. The 'sticks' holding the hydrogens to the oxygen represent covalent bonds
Why does the water molecule look bent?
The water molecule maintains a bent shape (bent at 107.5 degrees actually) because of two considerations. First the tetrahedral arrangment around the oxygen and Second the presence of lone pair electrons on the oxygen.
What are Lone Pair Electrons?
These are the electrons that are not involved in the covalent bonds. The pairs of electrons are left alone. In our picture they are represented by the double dots. These lone pairs are very negative - containing two negative electrons each - and want to stay away from each other as much as possible. These repulsive forces act to push the hydrogens closer together
Did you say "Tetrahedral" - What does that mean?
Tetrahedral means "four-sided". In chemistry we interpret this in our imaginations. Draw the central atom in an imaginary space. Next put the atoms attached to the central atom around it such that the distance between them is maximized. The arrangement you'll adopt will be the form of a regular tetrahedron. This molecular shape is shown below. It has regular bond angles of 109.5
IMAGE SOURCE: "Chemistry and Life", 4th Edition, John W. Hill, Dorothy M. Feigl, and Stuart J. Baum, Macmillan Publishing Company, New York, 1993
If we do a similar arrangement of water, putting oxygen in the center, and using the two hydrogens and two lone pairs at the corners, we also come up with a tetrahedral arrangement. However, there is one important difference - the bond angles for water are not 109.5. Because of the presence of the very negative lone pair electrons, the two hydrogens are squeezed together as the two lone pairs try to get away from each other as far as possible. The resulting angle gives water a 104.5 bond angle. Because we don't "see" the electrons, the resulting tetrahedron "looks" BENT!
IMAGE SOURCE: "Chemistry and Life", 4th Edition, John W. Hill, Dorothy M. Feigl, and Stuart J. Baum, Macmillan Publishing Company, New York, 1993
What's your Point?
Like many things in the chemical world, the shape and structure of a molecule is an important determinant of its function. The importance of the bent structure of water is that it provides water with two distinct "sides": One side of the water molecule has two negative lone pairs, while the other side presents the two hydrogens. Let's take another look:
[ fig of electron density map of water ]
Does this make water unusual?
YES! But it's not just that the molecule is bent that makes it special. Water is also highly polar - the two sides of water have very different charge.
The lone pairs are negative - Are the Hydrogens positive?
The hydrogens are slightly positive. They get this way because of the "electronegativity" of oxygen. Electronegativity is a measure of how much one atom wants to have electrons, and oxygen wants to have electrons more than hydrogen does. Oxygen has a higher electronegativity. Because of this difference in electronegativity, the electrons in the covalent bonds between oxygen and hydrogen get pulled slightly toward the oxygen. This leaves the hydrogens a little bit electron-deficient and thus slightly positive. We can draw this polarization like this:
IMAGE SOURCE: "Chemistry in Context" Wm C Brown Publishers, Dubuque Iowa, 2nd edition, A project of the American Chemical Society, ed: A. Truman Schwartz et al., 1997, Chapter 5 "The Wonder of Water
Or looking at it from a "net polarization" perspective, like this:
IMAGE SOURCE: "Chemistry and Life", 4th Edition, John W. Hill, Dorothy M. Feigl, and Stuart J. Baum, Macmillan Publishing Company, New York, 1993
What does the polarization have to do with the properties of water?
Everything! Because water has a slightly negative end and a slightly positive end, it can interact with itself and form a highly organized 'inter-molecular' network. The positive hydrogen end of one molecule can interact favorably with the negative lone pair of another water molecule. This interaction is call "Hydrogen Bonding". It is a type of weak electrostatic attraction (positive to negative). Because each and every one of the water molecules can form four Hydrogen Bonds, an elaborate network of molecules is formed.
IMAGE SOURCE: "Chemistry in Context" Wm C Brown Publishers, Dubuque Iowa, 2nd edition, A project of the American Chemical Society, ed: A. Truman Schwartz et al., 1997, Chapter 5 "The Wonder of Water"
But if the Hydrogen Bonds are weak, how can they be important?
Think of how many there are! There is strength in numbers!
The polarity also allows water interact with an electric field:
And to interact with other polar molecules - which is how substances become dissolved in water become dissolved in water
IMAGE SOURCE: "Chemistry in Context" Wm C Brown Publishers, Dubuque Iowa, 2nd edition, A project of the American Chemical Society, ed: A. Truman Schwartz et al., 1997, Chapter 5 "The Wonder of Water"
8] Reference of water in Religions
In the Vedas, water is referred to as the "most maternal" (mätritamäh)
The holy books of the Hindus explain that all the inhabitants of the earth emerged from the primordial sea
At the beginning of the Judeo-Christian story of creation, the spirit of God is described as "stirring above the waters," and a few lines later, God creates "a firmament in the midst of the waters to divide the waters" (Genesis 1:1-6)
In the Koran are the words "We have created every living thing from water"
In Judaeo-Christian culture, God is called "the fountain of living waters" (Jeremiah 2.13)
In China, the water of the fountain at Pon Lai was believed to confer a "thousand lives on those who drink it," according to Wang Chia, writing in the Chin Dynasty (265-420 CE)
In China, water is considered the specific abode of the dragon, because all life comes from the waters
In the Canticle of the Sun, St. Francis of Assisi praises God for water: "Praised be Thou, O Lord, for sister water, who is very useful, humble, precious, and chaste"
In Japan, water prefigures the purity and pliant simplicity of life
In India, the sacred River Ganges embodies for Hindus the water of life
9] Vital utilities of water
Water constitutes the greater part of the fundamental substance (protoplasm) of which animal and plant bodies are made
Sap of plants and blood of animals contain large quantities of water
Water is essential to the manufacture of starch by plants
Many foods, such as milk and fruit, have high water content
Water's composition by weight is one part of hydrogen to eight of oxygen (or 11.1 percent of hydrogen and about 88.9 percent of oxygen)
Water is an agent in erosion of the land
By convention, one cubic centimeter of water at 4°C. (its temperature at maximum density) weighs one gram
Unlike other liquids, water expands in freezing
Completely pure water is a poor conductor of electricity
Mineral water contains a great variety and quantity of minerals (usually a compound of calcium, magnesium, or iron)
Salt water contains a large amount of sodium chloride (common salt)
10] USA uses maximum amount of water
The United States uses three times as much water a day as the average European country, and many, many times more water than most developing nations
11] Some unique features of water
Pure water freezes at 0C but is most dense at 4 C. That is, solid water (ice) is less dense than cold liquid water.
Water has a high heat capacity: it takes much more heat to raise the temperature of a volume of water than the same volume of air.
This property of water is a major determinant of global climates and rates of global climate change.
BIOLOGY and WATER
Professor Linda S. Fink
12] The PHYSICS of WATER on EARTH
Professor George Lenz
Professor Hyman has described how the chemical building blocks of water, hydrogen and oxygen, were formed in the "big bang" and in the interior of stars by a process known as nuclear synthesis. In the last few years planetary probes have detected tantalizing evidence that water may exist on other bodies in our solar system, though in fact no other planet or moon in our solar system has the amount of liquid water present on the earth.
The earth appears to be unique in our solar system in that it contains an enormous amount of water, and that water has existed in a form not too different from its present state for billions of years Given that the laws of the nature operate everywhere in the solar system, we have to question why we are so privileged to have large bodies of liquid water on our planetary surface for so long a time. What makes the earth different from the other planets? To answer that question, we have to deal with two issues. 1) How did the earth acquire such a large amount of water in the first place, and 2) Once acquired, how was it retained ?
The first question has to do with how the earth was formed and the
second involves the evolution of the earth and its atmosphere. As we shall see, the long term existence of our watery planet as a place hospitable for the evolution of life involves a considerable amount of good luck.
The most recent theories of of planet formation describe the process of planet formation as having two steps. First, gravitational collapse takes place forming small asteroid like bodies some as large as 1/500 of the mass of the earth. The. planetesimals begin to collide and form the larger bodies of the planets. The rain of bodies on the surface of the earth generates large amounts of heat, enough to cause the heavier elements, such as iron to migrate to the center. A second factor has to do with the fact that when a meteor hits anything, some of it sticks and some is scattered back into space by the impact. The lower the density of the material, the more likely it is to escape. In the early stages, the earth collects heavier stuff more easily, leaving lighter stuff such as silicon and water still in orbit about the sun.
As the earth gets bigger, however, it more effectively traps the lighter material during the latter stages of planet formation.
The formation of the earth probably took a few hundred million years to be completed. That is to be compared with the time of about 3.5 billion years since the earth has developed a solid crust. About the time the earth was formed, the sun became large enough that the fusion reactions in the sun ignited. This didn't happen smoothly, but likely in sputtering way for a while. Each flaring up of the sun sent streams of particles sweeping out. If the earth had an atmosphere at this time, it would have been blown off leaving the earth as a rock with neither air or water on its surface. In fact, after the sun stabilized, the earth went through a process of releasing gases from its interior in a process called degassing. Over a relatively short time, something like a 100 million years, enough material had been released to form the oceans and to give the earth an atmosphere. There was no free oxygen in the atmosphere at this time, but it was a collection of gases, largely ammonia, methane and carbon dioxide, held to the earth by gravitational attraction. Fortunately, early in its history, the temperature of the earth dropped below 212 degrees Fahrenheit, and the water condensed into the oceans we know today.
In fact, the mass of water present in the oceans, now about 10(24) grams, is about the same as the mass of water that was contained in the crust when the degassing process started. We can estimate the rate at which water is being lost today by estimating the rate at which water molecules in the atmosphere are dissociated into its constituent hydrogen and oxygen. The hydrogen is light enough that it easily moves off into space. The net effect of hydrogen loss decreases the amount of water vapor in the atmosphere. A good estimate is that 5x10(11) grams are lost this way each year. This amounts to a volume of a cube about 100 yards on a side. The total water lost to space since the beginning of the earth thus amounts to about 2x10(21) grams, about 0.2 percent of the water in the oceans.
This means that most of the water you see on the earth was the very same stuff that degassed from the crust when the earth was only a few hundred million years old.
Fortunately, the water lost to space is replaced by the same geologic processes that formed the oceans originally.
At the present time, about 70%of the surface of the earth is covered with water. The present coastlines are where they are because some of the water is locked up in the polar ice caps.
In terms of volume, the water on earth is distributed in the following way:
· 1.35 x10(17) cubic meters (97.3%) Oceans
· 29x10(15) cubic meters (2.1%) polar ice and glaciers
· 8.4x10(15) cubic meters (0.6 %) underground aquifers (fresh)
· 0.2x10(15) cubic meters (0.01%) lakes and rivers
· 0.013x10(15) cubic meters (0.001%) atmosphere (water vapor)
· 0.0006x10(15) cubic meters (0.00004%) biosphere.
If the water locked up in polar ice were to completely melt, the oceans would rise about 240 feet above its present level.
The second question we raised, Why is the water still here on the earth?, is more difficult to answer. It has to do with the changing nature of the atmosphere due to evolution of life, specifically algae. The algae produced free oxygen by photosynthesis which destroyed ammonia and methane, so called greenhouse gases, just as the sun's luminosity was increasing by about twenty five percent. If that hadn't happened the oceans would have boiled away long ago. In fact, we are the beneficiaries of an incredible balancing act which allowed just enough heat to escape from the earth to keep the oceans from boiling, but not so much as to cause the earth to freeze solid.
With this as an introduction to the origins of our watery planet, I will turn in class to consider the role water plays in defining our weather (climate) on decadal or centennial time scales.
Suggested Readings
· National Geographic,Vol. 195 #3, March 1999. Article on El Niño and La Niña (also online here)
· The Changing World of Weather,Carpenter Guiness Publishing Co. , Enfield, Middlesex
· A Scientist at the Seashore,Trefil Collier Books, (1984)
13] WATER TRIVIA
· The only water we will ever have is what we have now.
· Showers use 9 gallons of water per minute.
· A bath requires 30 to 50 gallons.
· When ground water is contaminated it may remain that way for several thousand years.
· It takes 120 gallons of water to produce an egg.
A hot water faucet that leaks 60 drops per minute can waste 192 gallons of water and 48
kwhrs of electricity per month.
· Human blood is 83% water. Human bones are 25% water.
· Running the tap waiting for water to get hot or cold can waste 5 gallons per minute.
· Saltwater is 97% of water on earth. Three percent is freshwater. Most of the freshwater stored on the earth is frozen in glaciers.
· Each day the sun evaporates 1,000,000,000,000 (one trillion) tons of water.
· The earth's surface is about 80% water. That is about 320,000,000,000,000 (363 trillion) gallons of water.
· Watermelons is 93% water.
· "Water" was the first word that Helen Keller learned. "Water was the last word spoken by President Ulysses S. Grant.
· In some deserts, rain is so uncommon that the natives to not have a word for it.
· Over 42,000 gallons of water are needed to grow and prepare the food for a typical Thanksgiving dinner for eight in the United States. This is enough to fill a 30 by 50 foot swimming pool.
· People in the United States use as much as 700,000,00,000 (700 billion) gallons of water each day.
· Heating water is the second largest energy user in the home.
· In some countries law requires solar heating of water for domestic uses.
· The koala bear and the desert rat do not drink water.
· In one glass of water, there are about 8,000,000,000,000,000,000,000,000 (8 septillion water molecules.
· In a one hundred year period, a water molecule spends 98 years in the ocean, 20 months as ice, about 2 weeks in lakes and rivers, and less than a week in the atmosphere.
· Poor quality drinking water kills the equivalent of 20 jumbo jets filled with children every day.
· A corn plant needs 54 gallons per season.
· A milk cow needs 15 gallons per day or 5,475 gallons per year.
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· A horse needs 10 gallons per day or 3,650 gallons per year.
· A hog needs 4 gallons per day or 1,500 gallons per year.
· An acre of sugar beets consumptively uses 651,702 gallons or 2 acre feet per season
· An acre of alfalfa needs 488,776 gallons per season in Colorado and 684,240 gallons in New Mexico.
· One bail of has requires 17,000 gallons.
· One truckload of 450 bails of has requires 7,650,000 gallons or 23.47 acre feet
14] WATER MEASURES
· A Cubic Foot per Second or a Second Foot is also called a CFS. It equals 448.8 U.S. gallons per minute.
· One-Acre Ft. is the amount of water necessary to cover one acre of land to a depth of one foot deep. It is equal to 325,851.45 U.S. gallons.
· An irrigation is about six inches of water per acre unless the soils are saline when extra water is needed. An irrigation will usually penetrate 4-6" deep. If soils are saline additional water is needed to flush salts from the root zone.
· A Miners-Inch varies between 11.69 gpm in Colorado and 8.98 to 11.22 gpm in other western states of the United States.
· One U.S. gallon is 0.8327 Imperial gallons
· One cubic foot is 7.48062 U.S. gallons One cubic meter is 264.2 U.S. gallons
· One acre foot is 1,233.26 cubic meters
15] Surface tension of water
Water molecules at the surface (next to the air) hold closely
together, forming an invisible film. We call this water’s surface tension. Water’s surface tension can hold weight that would normally sink. You can carefully float a sewing needle or paper clip on top of water in a glass. Surface tension allows many aquatic insects, like water spiders and pod skaters, to “walk” across rivers and streams. Next to mercury water has the highest surface tension of all commonly occurring liquids Surface tension is essential for the transfer of energy from wind to water to create waves. . Waves are necessary for rapid oxygen diffusion in lakes and seas
16] True shape of rain drops
Are rain drops tear shaped?
When a drop of water comes out of the faucet, yes, it does have a tear shape. That is because the back end of the water drop sticks to the water still in the faucet until it can’t hold on any more. But, using high-speed cameras, scientists have found that falling raindrops look more like a small hamburger bun! Gravity and surface tension come into play here. As rain falls, the air below the drop pushes up from the bottom, causing the drop to flatten out somewhat. The strong surface tension of water holds the drop together, resulting in a bun shape (minus the sesame seeds) ( Small raindrops with a radius<1mm are spherical; larger ones look more like the hamburger bun until they get larger than about 4.5 mm at which point they become distorted into a shape rather like a parachute with a tube of water around the base—and they break up into smaller drops.) When the drop is small, surface tension wins and pulls the drop into a spherical shape. With increasing size, the fall velocity increases and the pressure on the bottom increases, causing the raindrop to flatten and even develop a depression. Finally, when the radium exceeds about 4mm or so, the depression grows almost explosively to form a bag with an annular ring of water and then it breaks up into smaller drops.
·
17]MOUNTAINS AND WATER
Mountains have been described as the water towers of the world. Almost all major rivers have their sources in mountains, and more than half of humanity relies on water from these rivers for domestic irrigation, industry, and the generation of hydroelectric power. These waters are also essential to the health of ecosystems since they provide nutrients for aquatic life and dilute pollutants generated mostly in the lowland areas.
18] THE WORLD’S WATER- A GRAPH
19] River pollution from raw sewage
In many developing countries, river pollution from raw sewage reaches levels thousands of times higher than the recommended safe limits for drinking and bathing.
Robin Clarke. 1993.Water: The International Crisis. Cambridge: MIT Press
cremated corpses and millions of tons of sewage can all be found in the holy waters of the Ganges.
John Ward Anderson. "The Great Cleanup of the Holy Ganges." The Washington Post, September 25, 1992.
20] Drinking and bathing in polluted water supplies are among the most common routes for the spread of infectious disease, and nearly half the world's population suffers from water-related diseases.
Robin Clarke. 1993.Water: The International Crisis. Cambridge: MIT Press
21] who are the people affected most by polluted waters and where do they live?
Most of those affected are poor, and almost all live in developing countries.
Our Planet, Our Health: Report of the WHO Commission on Health and the Environment. 1992. Geneva:World Health Organization.
22] water borne diseases the great killer of infants
water borne ‘diseases are the single largest killers of infants in developing countries--diarrhea alone causes 4 million deaths a year
-and access to safe water correlates strongly with the survival of children under five years old’
"Peter H. Gleick, ed. 1993. Water in Crisis: A Guide to the World's Fresh Water Resources. New York; Oxford University Press
With many water-short households forced to rely on contaminated water supplies, waterborne diseases like schistosomiasis and cholera are on the rise
23] Urban land use changes and water quality
The changes in land use patterns brought about by urbanization also affect renewable water supply, by altering and accelerating natural patterns of runoff, eroding soils and speeding evaporation. Urban runoff--collecting toxic compounds from sewage, vehicle exhaust and industrial pollution--severely degrades water quality.
24] Activities that accelerate water run off
Beyond the urban fringe, the expanding development of rural land is also cutting into the availability of renewable fresh water. Deforestation and the degradation of agricultural soil can accelerate or otherwise alter the water cycle, threatening the continuity of river and groundwater recharge. The dominant hazard is flooding, which can wash away topsoil and slowly choke rivers, dams and reservoirs with deposited sediment. Rapid population growth, which contributes to unsustainable farming practices and deforestation in countries like Nepal and India, has so reduced the water-absorbing capacity of the land in the Himalayan watershed that floods are devastating Bangladesh downstream on the Ganges and Brahmaputra rivers, with increasing frequency.
Radharkrishna Rao. 1989. "Water Scarcity Haunts World's Wettest Place." Ambio, 18(5).
Meteorological factors affecting runoff:
Type of precipitation (rain, snow, sleet, etc.)
Rainfall intensity
Rainfall amount
Rainfall duration
Distribution of rainfall over the drainage basin
Direction of storm movement
Antecedent precipitation and resulting soil moisture
Other meteorological and climatic conditions that affect evapotranspiration, such as temperature, wind, relative humidity, and season.
Physical characteristics affecting runoff:
Land use
Vegetation
Soil type
Drainage area
Basin shape
Elevation
Slope
Topography
Direction of orientation
Drainage network patterns
Ponds, lakes, reservoirs, sinks, etc. in the basin, which prevent or alter runoff from continuing downstream.
Runoff from agricultural land (and even our own yards) can carry excess nutrients, such as nitrogen and phosphorus into streams, lakes, and ground-water supplies. These excess nutrients have the potential to degrade water quality.
25] The United Nations declared the 1980s the Drinking Water Supply and Sanitation Decade, and the next 10 years saw 1.3 billion people supplied with new water sources and 750 million with sanitation. Yet at the end of the decade, 1-2 billion people still lacked safe water and 1.7 billion lacked sanitation services. The UN estimated in 1990 that population growth alone would add nearly 900 million people to these categories in the coming decade, with investments in infrastructure unlikely to keep pace.
Peter H. Gleick, ed. 1993. Water in Crisis: A Guide to the World's Fresh Water Resources. New York; Oxford University Press
26] A sensible estimation and understanding of available fresh water
Understanding the limits of renewable fresh water supply requires an appreciation of how little of the planet's 1.4 billion cubic kilometers of water actually fits into that category. Only 2.5 percent is fresh--fit for drinking, growing crops and most industrial uses. Moreover, 69 percent of that is locked in polar ice caps and mountain glaciers or stored in underground aquifers too deep to tap under current and foreseeable technology.
In calculating how much fresh water is available for human use, what counts is not the sum total of global fresh water supplies, but the rate at which fresh water resources are renewed or replenished by the global hydrologic cycle. Powered by the sun, this cycle each year deposits about 113,000 cubic kilometers of water on the world's continents and islands as rain and snow. Of that, about 72,000 cubic kilometers evaporates back into the atmosphere. That leaves 41,000 cubic kilometers a year to replenish aquifers or to return by river or other runoff to the oceans.
Igor A. Shiklomanov. 1993. "World Fresh Water Resources," in Peter H. Gleick,ed., Water in Crisis: A Guide to the World's Fresh Water Resources. New York: Oxford University Press
27] Experts’ estimation of available fresh water
Some water experts suggest the practical upper limit of the world'savailable renewable fresh water lies between 9,000 and 14,000 cubic kilometers per year. And a substantial proportion of this amount is needed to sustain natural ecosystems--in and around rivers, wetlands and coastal waters--and the millions of living species they contain.
Robin Clarke. 1993. Water: The International Crisis. Cambridge: MIT Press. and
Sandra Postel. 1992. Last Oasis: Facing Water Scarcity. Worldwatch Institute. New York: W.W. Norton.
28] which activity uses maximum water?
Worldwide, agriculture is the single biggest drain on water supplies, accounting for about 69 percent of all use. About 23 percent of water withdrawals go to meet the demands of industry and energy, and just 8 percent to domestic or household use.
World Resources Institute. 1993.World Resources 1992-93. New York: Oxford University Press.
29] which countries enjoy abundant water resources and why?
Nations such as Sweden or Iceland, where precipitation is high and evaporative demand low, enjoy abundant water resources
30] Draught in a place which receives maximum rainfall in the world- thanks to human mismanagement
Even those who live in areas of high rainfall in India often face drought because landscapes have been denuded. Soil is compacted and most rainfall runs off before it can sink into the ground, increasing flooding. The region of Cheerapunji in Meghalaya, for example, receives among the highest levels of mean rainfall recorded in the world. Yet because of intense seasonal rainfall and the fact that the area's forests have been cleared in the past few decades to meet growing demands for agricultural land and housing, much of the runoff cannot be captured. The region now suffers from excessive flooding for three or four months and frequent droughts the rest of the year.21 With a rapidly growing population of 1.8 million, Cheerapunji's water shortages and desertification will likely worsen.
Radharkrishna Rao. 1989. "Water Scarcity Haunts World's Wettest Place." Ambio, 18(5)
31] Need for changing patterns/methods of water usage for agriculture
Only a small fraction of the water that covers a farm field ever enters the root of a cultivated plant. That simple fact suggests tremendous reductions could be made in the two thirds of all water use that is now devoted to agriculture. These savings alone could perhaps meet the domestic water needs of the world's current population.
Sandra Postel. 1989. "Water for Agriculture: Facing the Limits." Worldwatch Paper 93. Worldwatch Institute.
Israeli farmers, whose drip-irrigation techniques achieve up to 95 percent efficiency, have more than doubled their food production in the last 20 years without increasing their use of water.
Priit J. Vesilind. "Middle East Water--Critical Resource." National Geographic, May, 1993.
32] The actual availability of fresh water in the world
33] When rainfall becomes groundwater, how does it actually move through the ground?
The water is stored in pores and fractures within the rock. Pores are the spaces between the grains. Above the water table, in the unsaturated zone, these pores are filled mainly with air. Below the water table, in the saturated zone, they are filled with water. It’s from the saturated zone that wells abstract water. Rocks vary in their ability to store and transmit water. Those that are capable of yielding water to wells in usable quantities are called aquifers. Some aquifers, usually those made of sand and gravel, transmit water through the pores, or spaces between the grains. Other aquifers, usually those composed of bedrock, transmit water through fractures in the rock
Why is there ground water?
A couple of important factors are responsible for the existence of ground water:
(1) Gravity
Nothing surprising here - gravity pulls water toward the center of the Earth. That means that water on the surface will try to seep into the ground below it.
2) The Rocks Below Our Feet
The rock below the Earth's surface is the bedrock . If all bedrock consisted of a dense material like solid granite, then even gravity would have a hard time pulling water downward. But Earth's bedrock consists of many types of rock, such as sandstone, granite, and limestone. Bedrocks have varying amounts of void spaces in them where ground water accumulates. Bedrock can also become broken and fractured, creating spaces that can fill with water. And some bedrock, such as limestone, are dissolved by water -- which results in (large cavities that fill with water.
In many places, if you looked at a vertical cross-section of the earth you would see that rock is laid down in layers, especially in areas of sedimentary rocks . Some layers have rocks that are more porous than others, and here water moves more freely (in a horizontal manner) through the earth. Sometimes when building a roadcenter of the Earth.
Try as it might, gravity doesn't pull water all the way to the center of the Earth. Deep in the bedrock there are rock layers made of dense material, such as granite, or material that water has a hard time penetrating, such as clay. These layers may be underneath the porous rock layers and, thus, act as a confining layer to retard the vertical movement of water. Since it is more difficult for the water to go any deeper, it tends to pool in the porous layers and flow in a more horizontal direction across the aquifer toward an exposed surface-water body, like a river.
Visualize it this way: get two sponges and lay one on top of the other. Pour water (precipitation) on top and it will seep through the top sponge downward into the bottom sponge. If you stopped adding water, the top sponge would dry up and, as the water dripped out of the bottom sponge, it would dry up too. Now, put a piece of plastic wrap between the sponges, creating your "confining layer" (making the bottom sponge an impermeable rock layer that is too dense to allow water to flow through it). Now when you pour water on the top sponge, the water will seep downward until it hits the plastic wrap. The top sponge will become saturated, and when the water hits the plastic wrap it won't be able to seep into the second sponge. Instead, it will start flowing sideways and come out at the edges of the sponge (horizontal flow of ground water). This happens in the earth all the time -- and it is an important part of the water cycle.
Information on this page is from Waller, Roger M., Ground Water and the Rural Homeowner, Pamphlet, U.S. Geological Survey, 1982
34] What do we mean when we talk about watersheds, river basins, catchment basins, and drainage basins?
Generally speaking, these four terms have similar meaning and are frequently used interchangeably. They refer simply to the total land area drained by a river and its tributaries. Originally, "watershed" denoted the imaginary line, or drainage divide, separating the waters flowing into different rivers or river basins, and is still often used in this context. Through common usage, it has also evolved to mean the area drained by a river system. "Drainage area" and "watershed" are more prevalent in North American practice, while "catchment" is customary in British and Australian water source communities. Canada's landmass is composed of five major drainage basins: Atlantic (which includes the Great Lakes and the St. Lawrence River); Pacific; Hudson Bay; Arctic; and the Gulf of Mexico. Each of these can be further divided into a hierarchy of progressively smaller basins or watersheds down to areas that drain individual lakes and rivers.
35] What do we mean by water quality?
Water quality is defined in terms of the chemical, physical, and biological content of water. The water quality of rivers and lakes changes with the seasons and geographic areas, even when there is no pollution present. There is no single measure that constitutes good water quality. For instance, water suitable for drinking can be used for irrigation, but water used for irrigation may not meet drinking water guidelines
36] What are the key factors that influence water quality?
Many factors affect water quality. Substances present in the air affect rainfall. Dust, volcanic gases, and natural gases in the air, such as carbon dioxide, oxygen, and nitrogen, are all dissolved or entrapped in rain. When other substances such as sulphur dioxide, toxic chemicals, or lead are in the air, they are also collected in the rain as it falls to the ground.
Rain reaches the earth's surface and, as runoff, flows over and through the soil and rocks, dissolving and picking up other substances. For instance, if the soils contain high amounts of soluble substances, such as limestone, the runoff will have high concentrations of calcium carbonate. Where the water flows over rocks high in metals, such as ore bodies, it will dissolve those metals. Another factor influencing water quality is the runoff from urban areas. It will collect debris littering the streets and take it to the receiving stream or water body. Urban runoff worsens the water quality in rivers and lakes by increasing the concentrations of such substances as nutrients (phosphorus and nitrogen), sediments, animal wastes (fecal coliform and pathogens), petroleum products, and road salts.Industrial, farming, mining, and forestry activities. also significantly affect the quality of rivers, lakes, and groundwater. For example, farming can increase the concentration of nutrients, pesticides, and suspended sediments. Industrial activities can increase concentrations of metals and toxic chemicals, add suspended sediment, increase temperature, and lower dissolved oxygen in the water. Each of these effects can have a negative impact on the aquatic ecosystem and/or make water unsuitable for established or potential uses.
37] How do we measure water quality?
The quality of water is determined by making measurements in the field or by taking samples of water, suspended materials, bottom sediment, or biota and sending them to a laboratory for physical, chemical, and microbiological analyses. For example, acidity (pH), colour, and turbidity (a measure of the suspended particles in the water) are measured in the field. The concentrations of metals, nutrients, pesticides, and other substances are measured in the laboratory.
Another way to obtain an indication of the quality of water is biological testing. This test determines, for example, whether the water or the sediment is toxic to life forms or if there has been a fluctuation in the numbers and kinds of plants and animals. Some of these biological tests are done in a laboratory, while others are carried out at the stream or lake.
38] What is good quality drinking water?
Good quality drinking water is free from disease-causing organisms, harmful chemical substances, and radioactive matter. It tastes good, is aesthetically appealing, and is free from objectionable colour or odour.
39] Is it possible to eliminate pollution by boiling all the water we consume?
No. Boiling water kills germs but will not remove heavy metals and chemicals
Boiling the water will actually INCREASE the amount of nitrate remaining in the water, increasing the danger to infants. If you have high nitrate water, either treat it with an approved treatment methodology or find another source: Boiling will only make it worse!
40] Is chlorine in the water supply necessary, and could it become a health hazard?
Chlorine was introduced as a disinfectant in water treatment around 1900. It has since become the predominant method for water disinfection. Apart from its effectiveness as a germicide, it offers other benefits such as colour removal, taste and odour control, suppression of algal growths, and precipitation of iron and manganese. In addition, chlorine is easy to apply, measure, and control. It is quite effective and relatively inexpensive.
Chlorine as a disinfectant in water treatment can be a health hazard if its concentration or the concentrations of certain by-products (e.g., trihalomethanes, a chlorinated organic compound)
41] Some people say that you shouldn't pour solvents and other household chemicals down the drain because they pollute the rivers and lakes. Is that true? How else can I get rid of them?
While household chemical products are generally safe for the uses they are designed for, some may become harmful to the environment as they accumulate in it. For this reason you should not put these products down a drain. Most sewage treatment facilities are not capable of removing such toxic substances. You should also be aware, in most instances, that anything put into the storm sewer system goes directly to the receiving lake or river completely untreated. So, before you dump anything down a drain or into a storm sewer, remember that you or others may be drinking it some day.
For those substances that you have at home now and want to get rid of, such as old paint, find out whether there is a hazardous waste disposal site in your community and take them there. You may also contact your local environmental health officer for assistance. Make sure the containers are labeled to indicate the contents.
42] Eutrophication is a form of pollution. What is a eutrophic lake?
Eutrophication is the natural aging process of lakes as they become better nourished, either naturally or artificially. Eutrophication occurs naturally with the gradual input of nutrients and sediment through erosion and precipitation, resulting in a gradual aging of the lake. Humans speed up this natural process by releasing nutrients, particularly phosphorus, into rivers and lakes through municipal and industrial effluent and through increased soil erosion resulting from poor land use practices. Eventually, a lake will develop high nutrient concentrations and dense growths of aquatic weeds and algae. These plants die and decompose, causing depletion of dissolved oxygen in the water. This process often results in fish kills and changes in a lake's fish species. Ultimately, eutrophication will fill the lake with sediment and plant material.
43] Is the discharge of cooling water from electrical power plants a form of pollution?
Yes; it is called "thermal pollution". Thermal pollution, when not regulated, can be a problem. Artificially heated water can promote algae blooms, threatening certain species of fish and otherwise disturbing the chemistry of the receiving water body. When this water is not reused by industries or for heating in nearby communities, large amounts of energy and potential money is lost. When it is reused, it can also have an improved effect on climate change by displacing the use of some fossil fuels.
44] What effect can a dam have on the water quality of a river system?
Generally, rivers are dammed to create reservoirs for power production, downstream flood control, recreation, or irrigation. When a dam is constructed, the land behind it is flooded. This may mean the loss of valuable wildlife habitat, farmland, forests, or town sites. Accumulation of sediments in the reservoir can have a detrimental effect on water quality by creating increased concentrations of harmful metal and organic compounds in the reservoir. If vegetation is not removed behind the dam before flooding, other problems can occur. For example, the eutrophication process may occur at a faster rate and adversely affect the water quality. Silt is trapped behind dams, reducing fertility downstream as well as the capacity and life-span of the dam. Downstream silt must be replaced by expensive chemical fertilizer.
Dams always carry the danger of collapse due to earthquakes, flooding or sabotage. Casualties from dam collapse will be much higher than those from normal flooding.
45] What is dredging?
Dredging is the removal of sediments or earth from the bottom of water bodies using either a type of scoop or a suction apparatus. This material, often called "spoils", is then deposited along the shore, formed into islands, or transported elsewhere away from the site. Dredging is usually done to increase the depth or width of water channels for navigation or to allow increased flow rates to accommodate larger volumes of water
46] Can dredging do any harm?
Dredging can disturb the natural ecological balance through the direct removal of aquatic life. For example, in estuaries (part of the river mouth where fresh water and seawater are mixed), oyster beds can be destroyed; in the freshwater environment, those bottom-dwelling organisms on which fish depend for food may be eliminated from the food chain. In addition, when spoils are deposited directly in a water system, they may smother the remaining organisms, and silt or sediments released from dredging activities can cover and destroy fish feeding and breeding habitats.
Furthermore, contaminants accumulate over long periods of time in the sediments. Some toxic substances which may reside in the sediment (e.g., mercury) can re-enter the water system when the sediments are dredged. Such contaminants then endanger the health of water users, particularly the organisms that live in the body of water. Nutrients are also released by dredging. These can cause eutrophication of the system, resulting in oxygen depletion and possibly the death of fish and other aquatic organisms.
47] Can dredging be beneficial to the aquatic ecosystem?
Yes, in some instances, dredging is beneficial to the environment. Dredging can be used to enlarge or create wetlands and provide more habitat opportunities and greater biological diversity within targeted geographic area. In some cases, disturbed lake and river bottoms can be re-colonized once the actual dredging activities have stopped. Dredged spoils can be used to create islands and contoured shorelines which can provide nursery habitat for fish, nesting and staging habitat for waterfowl, and winter habitat for furbearing mammals. In many cases, however, the material removed by dredging (i.e., dredgeate) requires containment or treatment and would not be suitable for wildlife habitat creation.
Although dredging can disturb the normal balance and productivity of an aquatic ecosystem, proper attention to mitigation and construction procedures may result in the beneficial effects of dredging outweighing the negative effects.
48] What is acid rain?
Acid rain refers to rainwater that, having been contaminated with chemicals introduced into the atmosphere through industrial and automobile emissions, has had its acidity increased beyond that of clean rainwater. Acidity is measured on a pH scale. For example, vinegar, an acid, has a pH of 3, and lemon juice, another acid, has a pH of 2. It is generally accepted that rain with a pH less than 5.3 is acidic. Emissions of sulphur and nitrogen oxides from a variety of sources enter the atmosphere everyday. While in the atmosphere, these compounds combine with atmospheric water to form acids. The most common acids formed in this manner are sulphuric acid and nitric acid. When mixed with rain, these acids fall as wet deposition (acid rain). In the absence of rain, the particulate matter slowly settles to the ground as dry deposition. Together, wet and dry deposition of acidic substances is known as acid precipitation.
Acid rain is a uniquely human-related phenomenon. The burning of fossil fuels (coal and oil) by power-production companies and industries releases sulfur into the air that combines with oxygen to form sulfur dioxide (SO2). Exhausts from cars cause the formation of nitrogen oxides in the air. From these gases, airborne sulfuric acid (H2SO4) and nitric acid (HNO3) can be formed and be dissolved in the water vapor in the air. Although acid-rain gases may originate in urban areas, it is often carried for hundreds of miles in the atmosphere by winds into rural areas. That is why forests and lakes in the countryside can be harmed by acid rain that originates in cities.
49] How does acid deposition affect water quality?
The effects of acid deposition on water quality, although complicated and variable, have been well documented. Impacts from these acidic compounds in the atmosphere can occur directly, by deposition on the water surface, or indirectly, by contact with one or more components of the terrestrial ecosystem before reaching any aquatic system. The interactions of acid deposition with the terrestrial ecosystem, including vegetation, soil, and bedrock, result in chemical alterations of the waters draining these watersheds, eventually altering conditions in the lakes downstream.
The extent of chemical alteration resulting from acidic deposition depends largely on the type and quantity of the soils and the nature of the bedrock material in the watershed, as well as on the amount and duration of the precipitation. Watersheds with soils and bedrock containing substantial quantities of carbonate-containing materials, such as limestone and calcite, are less affected by acidic deposition because of the high acid-neutralizing capacity derived from the dissolution of this carbonate material.
50] What is acid mine drainage?
Acid mine drainage or, more generally, acid rock drainage, results when rock containing metallic sulphides, such as pyrite, become exposed to water and air. Examples of this are mine tailings and excavation of acid rock through highway construction. The rate of acid generation is greatly enhanced by the presence of sulphur-oxidizing bacteria.
The impact of this process is increased acidity and metal levels in receiving waters (surface water and groundwater) to the detriment of fish and other organisms, as well as to drinking water supplies.
51] Rivers are much more than flowing water
As Max Finkelstein of Canada's Heritage Rivers Program points out: 'They are the threads that bind the fabric of nature and humanity and define the world's mosaic of cultures and landscapes. Throughout the world, rivers are imprinted on the land, and in the hearts and minds of the people who live along their banks.'
The river waters mix, metaphorically at least, with the blood coursing through their veins. Perhaps there is a little bit of some river, somewhere, in all of us?
52] Comprehensive Assessment of the Freshwater Resources of the World
Report of the Secretary-General
"The holistic management of fresh water as a finite and vulnerable resource, and the integration of sectoral water plans and programs within the framework of national economic and social policy, are of paramount importance for actions in the 1990s and beyond.
"Integrated water resources management is based on the perception of water as an integral part of the ecosystem, a natural resource and social and economic good, whose quantity and quality determine the nature of its utilization. To this end, water resources have to be protected, taking into account the functioning of aquatic ecosystems and the perenniality of the resource, in order to satisfy and reconcile needs for water in human activities."
From Agenda 21, Chapter 18, paragraphs 18.6 and 18.8, as endorsed at the United Nations Conference on Environment and Development, Rio de Janeiro, June 1992.
EXECUTIVE SUMMARY
53] The assessment by this report shows that in many countries, both developing and developed, current pathways for water use are often not sustainable. There is clear and convincing evidence that the world faces a worsening series of local and regional water quantity and quality problems, largely as a result of poor water allocation, wasteful use of the resource, and lack of adequate management action. Water resources constraints and water degradation are weakening one of the resource bases on which human society is built.
54] Water use has been growing at more than twice the rate of the population increase during this century, and already a number of regions are chronically water short. About one-third of the world's population lives in countries that are experiencing moderate to high water stress partly resulting from increasing demands from a growing population and human activities. By 2025, as much as 2/3 of the world population would be under stress conditions.
55] Water shortages and pollution are causing widespread public health problems, limiting economic and agricultural development, and harming a wide range of ecosystems. They may put global food supplies in jeopardy, and lead to economic stagnation in many areas of the world. The result could be a series of local and regional water crises with global implications.
56]This report finds that in some cases people have taken action to reduce demand and pollution, thus relieving water stress. However, far more widespread and sustained action is essential to reverse many of the unsustainable trends. This report presents policy options designed to improve understanding of how to reach sustainable levels of water use, while satisfying a wide range of needs including agricultural irrigation, industrial development, domestic use and water to maintain natural ecosystems.
Among the findings of this report:
57]There is a steady increase in the number of regions of the world where human demands are outstripping local water supplies, and the resulting water stress is limiting the development, especially of poor societies. Due largely to poverty, at least one-fifth of all people do not have access to safe drinking water, and more than one-half of humanity lacks adequate sanitation. At any given time, an estimated one-half of the people in developing countries suffer from water and food related diseases caused either directly by infection, or indirectly by disease-carrying organisms that breed in water and food.
58] Water demands are so high that a number of large rivers decrease in volume as they flow downstream, with the result that downstream users face shortages, and ecosystems suffer, both in the rivers and in adjacent coastal areas. Many underground water resources, known as groundwater, are being drained faster than nature can replenish them.
59] A growing number of the world's rivers, lakes and groundwater aquifers are being severely contaminated by human, industrial and agricultural wastes. The pollution not only affects freshwater quality, but much of it flows into the world's oceans, threatening marine life. The future health of the oceans depends heavily on how the freshwater systems are managed.
60] High withdrawals of water, and the heavy pollution loads have already caused widespread harm to a number of ecosystems. This has resulted in a wide range of health effects, in which humans have been harmed by eating food from contaminated ecosystems. Reproductive failures and death in various wildlife species, particularly at higher levels in the food chain are being reported in various regions of the world. In addition, rising human demands will put increasing pressure on ecosystems. As more water is withdrawn for human uses, there is increasing need to make certain that an adequate water supply to wetlands, lakes, rivers and coastal areas are maintained to ensure the healthy functioning of ecosystems.
However, there are bright spots to note. There have been some significant improvements in water quality, particularly when citizen pressure for cleanups grew, and governments and industry responded. Most developed countries have begun
61] treating an increasing part of their municipal sewage, and a number of their industries are reducing discharges of many toxic substances. As a result, there have been improvements in the health of some wildlife species, and reduced risks to human health.
62] Some countries have also made impressive reductions in the amount of water needed for irrigation, industrial and municipal purposes by using more effective water management systems and better technologies. These improvements were usually driven by shortages, and by increases in the price of water. Improved irrigation water management leads to less seepage and pooling of water which have a favourable impact on the transmission of vector-borne diseases such as malaria and schistosomiasis.
63] On balance, these gains have not reversed either the general trend toward water shortages, nor the widespread decline in water quality. A number of studies by UN agencies show that many countries lack the capacity to do comprehensive water resources assessments that include not only water quantity and quality but other factors such as changes in population and industrial development. There is a need for countries to strengthen their capabilities in this regard in order to be able to meet more effectively current and future stresses on their water resources.
64] There are driving forces of change that could make water problems worse, unless actions are taken. Those forces include a world population that is now 5.7 billion, and is heading toward 8.3 billion by 2025. Much of this increase will be in the rapidly growing urban areas of developing countries, many of which are already experiencing serious water stress.
65] Another driving force will be increasing consumption of food and industrial goods produced using water. Irrigation already accounts for 70 per cent of the water taken from lakes, rivers and underground sources, and there will be pressure to use more water to produce food for the increasing population. An increasing number of water short countries will have to make choices about the amount of water they allocate for food production as compared to other uses. They may find that limited water resources are more profitably invested in producing goods that can be exported to buy food, rather than in trying to grow all their food at home. Countries will also face increasing demands for water supplies for industrial development, hydro-electric generation, navigation, recreation and domestic use. Unless development stays within the limits of water supplies, there could be shortages that hamper economic development.
66] Water pollution will continue to increase unless more effort is put into pollution prevention, increase sewage treatment, and employ cleaner and more water-efficient forms of industrial production. This means using substances that are less toxic, and reducing the release into the environment of potentially harmful materials that are used in agriculture, industry and homes.
67] Because of increasing competition among demands for a finite resource, there is already growing perception of water as an economic good and as a tradable commodity. As human demands grow, so will the price of water and possibly food prices, placing a heavier burden on the poorer strata of the worldþs population. Economic planners often neglect to account for the amount of water that will be needed for certain forms of development, especially food production, for the world of 2025.
68] Countries, often working in regional groups and with international institutions such as the United Nations, need to develop a broad range of water strategies based on the best information available. There is a need to use water more efficiently, reduce pollution, provide people with access to safe drinking water and sanitation, and work for a global trading system in which countries that lack enough water to grow all their own food will have access to food grown in water rich regions. Concerted actions are needed at the local, national and international level. These include incorporating water into economic analyses, which should change consumption patterns and reduce demand for water. Poverty alleviation will be closely linked to the success of water policies.
69] About 300 major river basins, and many groundwater aquifers cross national boundaries. It is essential for riparian countries to find ways of cooperating over the development and management of these transboundary water sources, if they are to maximize mutual benefits from the use of the resource.
70] There are many technologies to reduce water use. In some countries, waste water is already being treated and used for irrigation. A number of industries have developed or adopted water management techniques and technologies that greatly reduce water use. Irrigation can become much more efficient in delivering water directly to plants, and still be designed and maintained in a way that avoids or minimizes such harmful side effects as waterlogging and salinization of the soil. Changing to crops using less water together with sequencing and shifting growing seasons can as well reduce water use substantially.
71] The amounts of water available and its quality are directly related to such activities as forestry, farming, urban developments and industrial strategies. To make water use more sustainable, planners at all levels need to understand water issues, and make them a central part of their development plans. The wise management of both water quantity and quality has to be a central part of health, economic and social policies.
72] Water management must adopt an integrated approach, taking into account a wide range of ecological, economic and social factors and needs. Decision-making should include full public participation, with all sectors of society. In developing countries, women are the main providers of water for household uses, which makes it critical to involve them at all levels in the decision-making process.
73] In making decisions about water resources management it is important to have overall planning and coordination, but it is also helpful to delegate as much responsibility as possible to the lowest appropriate levels. This helps to ensure participation of more people with a stake in the success of water projects.
74] Water used for development should be considered as natural capital, an economic good, and the marketplace can help to decide where its services are best used to generate wealth. It is important to ensure that the way in which water resources are developed does not result in worsening poverty.
75] Because of the lengthy period of planning, design, and construction of large water resources projects, it is crucial for decision makers to start making plans based on the best evidence available. It is no exaggeration to say that water resources projects to meet the needs of societies and economies in 2025 must be started or be in an advanced planning stage within the next few years. It is essential to plan and design new projects in ways that avoid the past mistakes that resulted in excessive water use and degraded water quality.
76] The world faces many challenges over use of the environment as a source of natural resources and as a sink for wastes. Water has to be considered one of the main issues facing the world. It is as important as atmospheric change, deforestation, protection of biodiversity and desertification, all of which are linked to water management. Many of the negative trends will take years to reverse, so it is imperative that actions to reverse them begin immediately.
77] All people require access to adequate amounts of clean water, for such basic needs as drinking, sanitation and hygiene. In return, those who use water have a responsibility to see that water is used wisely and not degraded.
78] It will be vital to monitor and report on progress in dealing with water issues. Among the indices which measure the effectiveness of water management are:
o Human health, which has a direct correlation with vector and water borne diseases and water supply and sanitation.
o Environmental health, which correlates with water use and pollution discharges.
o Food production, with its correlation with nutrition, and the availability of affordable water.
79] A growing number of regions face increasing water stresses because more people are both polluting and demanding more water for all uses from a renewable but finite resource. They are thus suffering from scarcities caused by failure to adapt to the amount of water that is regularly made available by rain and snowfall.
80] Concern over the global implications of water problems was voiced as far back as the United Nations Conference on the Human Environment in Stockholm in 1972. It has been the focus of a number of meetings, including the United Nations Water Conference in Mar del Plata, Argentina, in 1977, the Global Consultation on Safe Water and Sanitation for the 1990s in New Delhi, India, 1990, the International Conference on Water and the Environment: Development Issues for the 21st Century, in Dublin, Ireland, and the United Nations Conference on Environment and Development in Rio de Janeiro, Brazil, both in 1992. Since then, the Interministerial Conference on Drinking Water Supply and Environmental Sanitation, in Noordwijk, The Netherlands, in 1994, reinforced these concerns. Most recently, the Committee on Natural Resources of the Economic and Social Council þnoted with alarm that some 80 countries, comprising 40 per cent of the worldþs population, are already suffering from serious water shortages and that, in many cases, the scarcity of water resources has become the limiting factor to economic and social developmentþ. It further noted that þever- increasing water pollution has become a major problem throughout the world, including coastal zonesþ. The UN Commission on Sustainable Development, at its second session in 1994, noted that in many countries a rapid deterioration of water quality, serious water shortages and reduced availability of fresh water were severely affecting human health, ecosystems and economic development.
81] The Commission requested this Comprehensive Assessment of the Freshwater Resources of the World, to be submitted at its fifth session, and to the Special Session of the General Assembly in 1997. This assessment was prepared by a number of UN organizations, the Department of Policy Coordination and Sustainable Development, Department of Development Support and Management Services, Food and Agriculture Organization, United Nations Development Programme, United Nations Environment Programme, UNESCO, UNIDO, World Bank, World Health Organization and World Meteorological Organization, working in collaboration with the Stockholm Environment Institute, and with the advice of experts on a wide range of subjects. The support given to this project by the Governments of Sweden, Norway, Denmark, the Netherlands and Canada is acknowledged with sincere appreciation.
82] The recommendations in this report were guided by reports from previous conferences, particularly the report of the Dublin water conference and Chapter 18 of Agenda 21. More recent information has also been evaluated, particularly on water availability and use.
83] This assessment provides an overview of major water quantity and quality problems with the aim of helping people understand the urgent need to deal with these issues before they become even more serious. In spite of its limitations, the available information provides the basis for a broad understanding of the problems facing various regions of the world, and of the nature and magnitude of the global implications of not dealing with these problems.
Figure 1. Water plays many complex roles in human activities and natural systems. A comprehensive approach must thus relate to water use from many different aspects. The assessment describes the human interaction within the economic, social and environmental framework. It seeks to point out how the systems are interacting through different global linkages such as cultural influences, environmental impacts, global governance and trade, showing that the socio-ecological system is complex with connections within and between the different subsystems.
I. THE SUPPLY, AVAILABILITY AND USE OF THE WORLD'S FRESH WATER RESOURCES
84] Fresh water is one of the most essential elements that supports human life and economic growth and development. It is irreplaceable for drinking, hygiene, food production, fisheries, industry, hydro power generation, navigation, recreation and many other activities. Water is equally critical for the healthy functioning of nature, upon which human society is built.
A. Water availability
Figure 2. Naturally dry zones of the world mean that there are limitations to the pattern of development that may be available on the basis of water resources availability, particularly for agriculture.
85] Many people have an image of the world as a blue planet, for 70 per cent of it is covered with water. The reality is that 97.5 per cent of all water on earth is salt water, leaving only 2.5 per cent as fresh water. Nearly 70 per cent of that fresh water is frozen in the icecaps of Antarctica and Greenland, and most of the remainder is present as soil moisture, or lies in deep underground aquifers as groundwater not accessible to human use. As a result, less than one per cent of the world's fresh water, or about 0.007 per cent of all water on earth, is readily accessible for direct human uses. This is the water found in lakes, rivers, reservoirs and those underground sources that are shallow enough to be tapped at an affordable cost. Only this amount is regularly renewed by rain and snowfall, and is therefore available on a sustainable basis.
Much of the approximately 110,000 cubic kilometres of precipitation that falls on the continents each year evaporates back into the atmosphere, or is absorbed by plants. About 42,700 cubic kilometres of water that falls on earth flows through the world's rivers. (This is roughly the amount of water now stored in some of the world's largest lake systems combined: Lake Baikal in Russia, and Lake Tanganyika and Lake Victoria in Africa combined.) When the world's total river flow is divided by the world population of 1995, that amounts to an average of 7,300 cubic metres of water per person each year. Due to the growing world population, that is a drop of 37 per cent per person since 1970
Figure 3. Average Annual Runoff. The amount of freshwater varies sharply among continents. The size of the population determines how much water is potentially available per person. While Asia has the world's greatest river flow, it has billions of people, so the per capita availability is the lowest of all the continents. The high per capita runoff in Australia/Oceania shows that despite the fact much of Australia is very dry, the population density is quite low, and there is very heavy rainfall in parts of the country, and on the Pacific islands.
86] Fresh water resources are very unevenly distributed, ranging from the deserts, where almost no rain falls, to the most humid regions, which can receive several metres of rainfall a year. Most of the flow is in a limited number of rivers: the Amazon carries 16 per cent of global runoff, while the Congo-Zaire River basin carries one-third of the river flow in all of Africa. The arid and semi-arid zones of the world, which constitute 40 per cent of the land mass, have only 2 per cent of global runoff.
87] Even in parts of the world with large river flows, there can be a great amount of variability in when and where the water is available. Most of the annual water flow may come as floods following snow-melt or heavy rains, and unless captured by reservoirs, it flows to the seas, sometimes causing seasonal flooding. Later in the year, the same areas may suffer droughts. Another major factor in the availability of water is the rate of evapotranspiration, the loss of water from land to atmosphere by evaporation from the soil and water surfaces, and transpiration from plants. For example, Sweden and Botswana receive about the same amount of precipitation each year, yet the climate in Sweden is humid, while that of Botswana is semiarid, because so much of its water is drawn up by the heat of the sun. One more important factor is that much of the world's accessible runoff occurs in areas far from human settlements, and water is very expensive to transport over long distances.
Present water withdrawal and consumption by sector.
88] Experts have estimated the amount of the fresh water that is readily accessible for human use at about 9,000 cubic kilometres a year. They add another 3,500 cubic kilometres of water that is captured and stored by dams and reservoirs. Harnessing the remaining water resource for human needs becomes increasingly costly, because of topography, distance and environmental impacts. Currently, humans are using about half the 12,500 cubic kilometres of water that is readily available. Given an expected population increase of about 50% in the next 50 years, coupled with expected increases in demand as a result of economic growth and life-style changes, this does not leave a great room for increased consumption. Water needs to be left in rivers to maintain healthy ecosystems, including fisheries. Recreation, navigation, and hydro power generation all require the preservation of adequate amount of water. When the global water picture is examined at a country level, some countries still have large amounts of water per capita, but others, however, are already facing serious difficulties. Future increases in demand due to population growth and increased economic activities will inevitably impinge further on the available water resources.
B. Water uses
A number of human actions are changing the flow of water in parts of the world, including the building of dams and canals, the drainage of wetlands, and removal of forests and other plant cover. Trees and other plants modify the flow of water that falls on the land, consume water, and release some into the atmosphere, where it may result in more rain
In the hydrological cycle, the sun constantly evaporates water into the atmosphere, part of which is returned on land as rain and snow. Part of that precipitation is rapidly evaporated back into the atmosphere. Some drains into lakes and rivers to commence a journey back to the sea. Part infiltrates into the soil to become soil moisture or groundwater. Under natural conditions, the groundwater gradually works its way back into surface waters and makes up the main source of dependable river flow. Plants incorporate some of the soil moisture and groundwater into their tissues, and release some into the atmosphere in the process of transpiration.
89] Humans interact with the hydrological cycle at many levels. We use surface water and groundwater. Pollution contaminates not only water on and beneath the ground, but it also changes the chemical composition of water in the atmosphere. Waste discharges from a wide range of sources, including motor vehicles, homes, offices and industries, as well as chemicals and animal wastes from agricultural production, leading an increasing number of decision makers to give these "environmental" flows priority along with water use for economic activities.
C. Water scarcity Water scarcity occurs when the amount of water withdrawn from lakes, rivers or groundwater is so great that water supplies are no longer adequate to satisfy all human or ecosystem requirements, bringing about increased competition among potential demands. Scarcities are likely to happen sooner in regions where the per capita availability of water is low to start with and with high population growth. They become more serious if demand per capita is growing due to changes in consumption pattern.
90] Global withdrawals of water to satisfy demands have grown dramatically in this century. Between 1900 and 1995, water withdrawals increased by over six times, more than double the rate of population growth. This rapid growth in water demand is due to the increasing reliance on irrigation to achieve food security, the growth of industrial uses, and the increasing use per capita for domestic purposes.
Global water withdrawals by sector, 1940-2000.
91] The increased demands are causing water stress in many areas of the world, even in some humid areas where rising demand or pollution have caused over utilization of the local resource. Already, about 460 million people, more than 8 per cent of the world's population, live in countries using so much of their water resources that they can be considered to be highly water stressed. A further one-quarter of the world's population lives in countries where the use of water is so high that they are likely to move into situations of serious water stress.
D. Human induced stresses
1. Quantity
92] Irrigated agriculture takes about 70 per cent of water withdrawals, and the figure rises to 90 per cent in the dry tropics. Agriculture is by far the biggest consumptive use of water, representing 87 per cent of the total. Traditionally, most food has been grown on rainfed lands, relying on soil moisture supplied by rainfall, but as food demand rises, this is increasingly supplemented by irrigation, using water drawn from lakes, rivers and underground aquifers. Irrigated agriculture contributes nearly 40 per cent of world food production from just 17 per cent of cultivated land. Much of the dramatic increase in food production of recent decades, including the Green Revolution, requires high-yield plant varieties, combined with fertilizers and pest control, and depends on irrigation to ensure adequate and timely water for high growth. Water withdrawals for irrigation have increased by over 60 per cent since 1960.
93] Until the late 1970s, the growth in the amount of land being irrigated exceeded the rate of population growth. Since then, the amount of irrigated land has increased more slowly than population, due to a limited amount of additional land suitable for irrigation, increasing water scarcities and the loss of some irrigated areas to soil degradation including soil salinization. However, total agricultural output has continued to outstrip population growth, owing to productivity increases. Currently, the world can produce enough food for everyone, but an estimated 840 million people are lack access to sufficient food for their nourishment, and are hampered in carrying on productive, working lives because they cannot afford to buy enough food. As the number of people to feed increases, it will be ever more of a challenge to produce enough food at prices people can afford. In many regions, in particular arid and semi-arid regions, the amount of water available for irrigation will become increasingly limited and costly.
Amount of irrigated land in the world, and water consumption for irrigation. Dark-coloured bars depict the amount of water consumption while light-coloured bars show the amount of land that is irrigated.
2. Impacts of demand for water
94] In some areas, the withdrawals are so high that the flow of rivers decreases as they move downstream, and some lakes are shrinking.
95] Groundwater supplies one-third of the world's population, and is the main or only source of water for rural dwellers in many parts of the world and is also increasingly the main source for irrigation. Underground sources are being heavily overused in a number of regions, with water being pumped out faster than nature can replenish the supply. The excessive use of groundwater is likely to increase over the next 30 years. Over pumping groundwater has dropped water levels by tens of metres in places, making it increasingly difficult and expensive for people to have continued access to the water. In a number of regions, depletion has forced people to turn to lower quality groundwater sources, some of which contain natural contaminants. The overuse of groundwater can have a serious effect on the base flow of rivers,
96]
Aral Sea
In 1960, the Aral Sea was the fourth largest inland body of water in the world. Since then it has shrunk to less than half its original size because of the nearly total cutoff of inflow from the Amu Dar'ya and Syr Dar'ya rivers as result of heavy withdrawals for irrigation. The desiccation of the Aral has resulted in the loss of its fishing industry, the destruction of its ecosystem and deltas, the blowing of salts from the exposed seabed which are toxic to humans and deleterious to crops, and depressing the economy. Indiscriminate use of water for non-agricultural purposes, inefficient irrigation practices, excessive use of chemicals for growing cotton and rice crops, and the lack of adequate drainage caused extensive waterlogging and salinity, and polluted the groundwater and drainage inflows to the rivers and the sea. Water pollution from urban and industrial wastes has further aggravated the problems. To stabilize the environment and rehabilitate the economy of the Aral Sea Basin, the governments of the five independent riparian states have begun a large and complex program intended to assist them to cooperate and adopt sustainable regional development policies, and to provide a framework for selected national macro-economic and sectoral policies to achieve sustainable land, water, and other natural resources development.
97] Many groundwater aquifers are recharged on a regular basis by rain and melting snows. However, some groundwater reservoirs that were filled under different climatic conditions, often thousands of years ago, are known as fossil aquifers, and if used, they will not be recharged by nature for a very long time, if ever.
98] In some cases, groundwater depletion results in the land above aquifers sinking. Land subsidence caused by high water withdrawals has been recorded in many countries, including Mexico, the United States, Japan, China and Thailand, with the land sinking from 1 to 10 metres.
99] Over utilization of aquifers near seacoasts leads to intrusion from the ocean, which contaminates the fresh water with salt. Small islands fall in a special category because for many of them fresh water is a fragile resource. If the fresh water is overdrawn, this leads to salt water intrusion. People on some small islands have been forced to turn to expensive alternatives, including desalination and importing water by tanker.
3. Water pollution issues
100] For millennia, people have used water as a convenient sink into which to dump wastes. The pollution comes from many sources, including untreated sewage, chemical discharges, petroleum leaks and spills, dumping in old mines and pits, and agricultural chemicals that are washed off or seep downward from farm fields. In one area after another, the amounts and types of waste discharged have outstripped nature's ability to break them down into less harmful elements. Pollution spoils large quantities of water which then cannot be used, or at best can be used for restricted purposes only.
101] The impairment of water quality near major urban centres is recognized as a major problem. In parts of the world, water quality has been so degraded that it is unfit even for industrial purposes. Even when the levels of some pollutants seem to be low, they can pose a threat by accumulating in the aquatic food chain, affecting the health of these creatures, and threatening the health of humans who eat contaminated wildlife. Groundwaters, once contaminated, are very difficult to clean up because the rate of flow is usually slow.
102] Among major water pollution problems:
Contaminated water that people drink without adequate treatment is one of the major cause of human illness. micro-organisms found in human and animal wastes include a wide range of bacteria, viruses, protozoa and other organisms that cause many diseases. These are present in virtually all wastes discharged, even those from most sewage treatment plants. As a result, it is necessary to treat drinking water to prevent outbreaks of disease.
103] Accelerated growth of algae fertilized by the phosphorus and nitrogen present in many discharges, including human and animal wastes, detergents and runoff from fertilizers. These two elements act as nutrients when discharged into water, greatly speeding up the process called eutrophication. Excessive algal growth leads to a decline in the oxygen content in the water, which can suffocate some forms of aquatic life. It can also impart a foul taste to drinking water. Eutrophication, first noticed in many Western European and North American Lakes in the 1950s, is now leading to the decline in water quality on all continents. When the nutrients drain into oceans, they can increase in the number of toxic algal blooms, sometimes known as red tides, which can make seafood unsafe to eat.
104] Nitrates from fertilizers, human and cattle wastes are polluting groundwater in many regions. High nitrate levels in drinking water decrease the oxygen carrying capacity of haemoglobin in blood, which can threaten the health of infants. A UN study say that nitrate pollution will likely be one of the most pressing water quality problems in Europe and North America in the coming decade, and will become a serious problem in other countries, such as India and Brazil, if present trends continue.
105] Some of the more than 100,000 commercial chemicals in the world, as well as a number of chemical waste by-products, are known or suspected to cause harmful effects in humans, plants and animals. One class of compounds, known as Persistent Organic Pollutants, which include such well-known substances as PCBs and DDT, has created many of the problems because they are toxic, highly persistent in the environment and they build up in the food chain. These and other chlorinate organic chemicals have been so widely distributed by air and ocean currents that they are found in the tissues of people and wildlife everywhere.
106] Heavy metals are found naturally in soil and water, but their worldwide production and use by industry, agriculture and mining have released large amounts into the environment. The metals of greatest concern for human health are lead, mercury, arsenic, and cadmium. Many other metals, including copper, silver, selenium, zinc and chromium, are also highly toxic to aquatic life. Water pollution related to metal production and use, including the release of acids from mining wastes, is a problem in many of the world's mining and metal processing regions. Elevated levels of some metals, such as lead and mercury, are also found around many cities, and downwind from metal smelters and coal-burning power plants.
107] In theory, virtually all pollutants can be removed from water, but in practice decontaminating water, especially in the case of toxic substances, is very expensive, and requires sophisticated techniques.
108] Water pollution problems vary in severity around the world, depending on population densities, the types and amounts of industrial and agricultural development, and the number and efficiency of waste treatment systems that are used. The global magnitude of pollution is difficult to quantify because of a scarcity of information in many countries. There are estimates that in developing countries, which often lack the resources to build and maintain sewage treatment systems, 90 per cent of waste water is discharged without treatment. A UN study found that in Latin America, virtually all domestic sewage and industrial waste is discharged untreated into the nearest streams. In most areas, domestic sewage volumes are far higher than those of industrial discharges. There were similar findings from West Africa, where there were signs of shallow aquifers being contaminated by the seepage of human wastes. In Western Asia, the major water quality problem identified was salinity caused by widespread irrigation, although other water quality problems may not be evident due to lack of monitoring programs. In the Asia and Pacific region, in addition to domestic and industrial wastes, there are also high sediment loads in rivers resulting from high erosion upstream where much land is left exposed due to the removal of forest.
109] The water pollution problems in many developing countries mirror those already experienced by developed countries in Europe and North America. A few decades ago some rivers in rich nations were so polluted that fires broke out on their oil-slicked surfaces. This was documented both in Canada and the United States. Due largely to public pressure, controls have been imposed on much of the gross pollution, and clean-ups are taking place, often at very high cost to the present generation.
110] While much of the world's pollution is directly released from discharge pipes and sewers, or is carried off polluted industrial, municipal and agricultural areas by rainfall and melting snows, a significant pollution load is transferred long distances by the atmosphere. Several decades ago researchers discovered that the release of tens of millions of tonnes of a year of sulphur and nitrogen caused sulphuric and nitric acid fallout. This acid rain affects large areas of the world, including parts of Europe, North America, Latin America, India and Asia. It has killed parts of ecosystems, and can threaten human health by dissolving metals into the water. In addition to acids, there is long-range airborne transport of a wide range of chemicals and metals from such sources industries, motor vehicles, power plants, smelters and incinerators. Pesticide use is another important source because some of the chemicals evaporate into the air, and others adhere to tiny dust particles, both of which can be carried great distances by wind currents. Sometimes, the pollutants build up in the food chain, and are passed on to humans who rely on wild foods. Tests of breast milk from women in some northern latitudes, where there is little industry and no agriculture, found levels of PCBs and certain pesticides were four to 10 times higher than in women from regions hundreds of kilometres to the south.
111] Since most lakes and rivers eventually drain to the seas, the freshwater waste discharges also have an impact on coastal and even deep-sea ecosystems. About 80 per cent of marine pollution is caused by human activities on land. The water in the oceans will never be clean, unless pollution from sources on land is not controlled.
E. Human health at risk due to water problems
112] . Water supply, sanitation and health
· The need to provide safe drinking water and sanitation and to reduce water contamination are basic questions of equity and protection for human health. They were emphasized in the Mar del Plata conference of 1977. In 1980, the UN General Assembly proclaimed in Resolution 35/18 that the period 1981-1990 would be the International Drinking Water Supply and Sanitation Decade, "during which Member States will assume a commitment to bring about a substantial improvement in the standards and level of services in drinking water supply and sanitation by the year 1990." The issue continued to receive attention at such intergovernmental conferences as the Global Consultation on Safe Water and Sanitation in New Delhi in 1990 and the Noordwijk conference of 1994.
·
Water supply service coverage (per cent of population served) at the end of 1994.
113] In the past two decades, these essential services were provided to millions of people world-wide, saving a great many lives and reducing illness. However, the rate of supply has not kept pace with that of population growth, and 20 per cent of the world's population lacks access to safe water supply, while 50 per cent lacks access to adequate sanitation. The vast majority of these people live in developing countries. This lack of access to safe drinking water and sanitation is directly related to poverty, and, in some cases, the inability of governments to invest in these systems. In a number of regions, poor people lack access to piped water, and must buy from vendors, so they pay more for their water than rich people.
114] A great deal of treated drinking water is lost unnecessarily. There are estimates that about half the water in drinking water supply systems in the developing world is lost due to leakage, illegal hookups and vandalism. This deprives operators of the water supply systems of money they could use to maintain and expand service. The World Bank estimates that about $600 billion needs to be invested worldwide to repair and improve water delivery systems.
Figure 9. Sanitation service coverage (per cent of population served) at the end of 1994. "No data" means that data was not available in the data base used for this study
115] Human health is closely linked to safe drinking water and sanitation, and to sound management of land and water resources, particularly in the context of water resources development projects. At any given time, an estimated one-half of the people in developing countries are suffering from water or food associated diseases caused either directly by infection through the consumption of contaminated water or food, or indirectly by disease-carrying organisms (vectors), such as mosquitoes, that breed in water. The most widespread of these diseases and with the greatest impact on human health status are diarrhoea, malaria, schistosomiasis, dengue, infection by intestinal worms, and river blindness (onchocerciasis). According to the World Health Organization, some 2 billion people are at risk of malaria alone, with 100 million people affected at any one time and between one and two million deaths a year.
116] The WHO estimates that a total of more than five million people die each year just from diseases caused by unsafe drinking water, and a lack of sanitation and water for hygiene. Provision of safe drinking water and sanitation could reduce the amount of illness and death by as much as three-quarters, depending on the disease. The toll is not only a human tragedy, but it means these people are less able to carry on productive lives, which undermines social and economic development. An outbreak of cholera, a water-borne disease, began in Peru a few years ago and spread through many parts of Latin America, killing hundreds of people, and costing hundreds of millions of dollars in lost income.
117] There are other economic impacts caused by poor water supply systems. Women are the main water providers, especially in developing countries, and the provision of basic drinking water supply systems could also reduce the annual expenditure of over 10 million person-years of effort by women and female children carrying water from distant sources. Reallocation of the time spend in this unproductive activity would assist in poverty alleviation.
2. Health effects of other contaminants
118] In humans, high levels of exposure to some chemicals and heavy metals have been linked to a number of illnesses, including cancer, damage to the nervous system and birth defects. Pollutants can build up in the food chain to the point that they harm people, as with Minamata disease caused by people eating seafood contaminated with mercury from industrial discharges. The cumulative effects of long-term exposure to a variety of chemicals at what seem like low concentrations cannot be well quantified at present. Studies in North America suggest a link between fetal exposure to high levels of some organochlorines and reduced learning ability in children. There is also suggestive evidence from wildlife studies that humans may be at risk from a number of subtle effects, such as disruptions in the endocrine system caused when synthetic materials interfere with the body's normal chemical balance.
119] Toxic chemical effects have been more clearly recorded in wildlife. The effects include, cancer, death, eggshell thinning, population declines, reduced hatching success, abnormal behaviour, changes in organ development, infertility, birth defects and a range of other illnesses. There are also less visible effects on body chemistry, including abnormalities in the thyroid, liver and endocrine systems. Some organochlorines appear to have the ability to mimic or block the normal functioning of hormones, interfering with natural body processes, including normal sexual development.
F. Stress on land resources
120] The stresses on water and land are closely linked. For thousands of years, humans have been drawing water from rivers and wells to irrigate dry lands thus growing more food. And, for millennia, inadequate drainage systems have resulted in waterlogging and soil salinization. The salinization happens when water in the ground evaporates, leaving behind natural salts that were present in the water. It is estimated that about 20 per cent of the world's 250 million hectares of irrigated land are salt affected to an extent that crop production is significantly reduced. A further one and one-half million hectares are affected each year. The countries most severely affected are predominantly located in arid and semi-arid regions.
Figure 10. Map of soil degradation.
121] The mismanagement of soil and water resources is also excarcebating erosion brought about by water. This depletes the land of soil and nutrients, and increases water pollution in the form of soil particles that often carry agricultural chemicals with them. When suspended soil particles arrive at a dam, they often sink to the bottom of the reservoir, gradually reducing the amount of water it can hold. This process has caused serious losses of reservoir capacity in a number of river basins.
The Murray-Darling Basin covers one-seventh of Australia, and accounts for half the country's gross agricultural production. As demands for water increased, reservoirs were constructed to increase the available supply to individual states. In recent years, use approached the sustainable yield of the basin as a whole, and pressure mounted for sharing the resource between jurisdictions. In 1985, a Basin Commission was formed and in 1989, agreement was reached on sharing. The next issue requiring resolution was soil salinity that had the potential to expand to 95 per cent of the total irrigated area within 50 years. The three upstream states were the primary beneficiaries of water diversion, while the damage caused by salinity was most severe in the downstream state. An agreement was reached on joint funding of remedial measures and collaboration was initiated, driven primarily from the community level. Action has been under way for four years, and the spirit of collaboration continues as a demonstration of integrated water management success.
G. Extent and geographical distribution of water stresses due to scarcity
122] In keeping with the concept of water scarcity previously defined, the ratio of water withdrawal to water availability on an annual basis is used as a measure of stress.
123] It has been observed that water stress can begin as the use of fresh water rises above 10 per cent of renewable freshwater resources, and it becomes more pronounced as the use level crosses the 20 per cent level. On average, a country can only capture about one-third of the annual flow of water in its rivers using dams, reservoirs and intake pipes. A further limitation arises from the growing lack of acceptance for the social and environmental impacts of large dams. The closest and most economical sources of water are used first, and it becomes increasingly expensive to tap sources that are farther away from the needs. Another limitation to water use is that once withdrawals pass certain thresholds, which vary from site to site, lake and river levels fall to the point that other uses are harmed.
124] This report distinguishes four categories of water stress based on the amount of available fresh water that is used.
125] Low water stress. Countries that use less than 10 per cent of their available fresh water generally do not experience major stresses on the available resources.
126] Moderate water stress. Use in the range of 10 to 20 per cent of available water generally indicates that availability is becoming a limiting factor, and significant effort and investments are needed to increase supply and reduce demand.
127] Medium-high water stress. When water withdrawals are in the range of 20-40 per cent of the water available, management of both supply and demand will be required to ensure that the uses remain sustainable. There will be a need to resolve competing human uses, and aquatic ecosystems will require special attention to ensure they have adequate water flows. Developing countries, in particular, will need major investments to improve water use efficiency and the portion of Gross National Product allocated to water resources management can become substantial.
128]High water stress. Use of more than 40 per cent of available water indicates serious scarcity, and usually an increasing dependence on desalination and use of groundwater faster than it is replenished. It means there is an urgent need for intensive management of supply and demand. Present use patterns and withdrawals may not be sustainable, and water scarcity can become the limiting factor to economic growth.
Figure 11. This map shows water withdrawal as a percentage of water availability. Calculations are based on both internal water resources and water available from upstream sources in international basins. Many countries with high water withdrawal rates are also very dependent on external water. Because the data used to prepare this map were gathered at a country level, there are some apparent contradictions. For example, the Sahel region does not show as having a high water stress, even though it is a dry region. This is because a number of countries in dry regions have relatively abundant water resources in part of the country, as in one large river, such as the Nile or Niger. They might also have abundant rainfall for part of the year. However, the poor countries in this category lack the financial and technical resources to capture rainfall or to move water to many of their people. Even water rich countries can have tremendous disparities internally.
H. Coping capability based on income levels
129] The ability of countries to cope with water scarcities, including the effects of pollution, depends on a number of factors. This report uses income levels as a rough measure of the ability of different groups of countries to deal with water issues. In general, countries with higher per capita incomes are in a better position than low-income countries to respond to water scarcity, as the financial resources and skilled people for management and development are more readily available. Because of low income levels, many developing countries face severe difficulties in creating the infrastructure to fully utilize their water resources.
130] The World Bank has grouped countries into four categories, based on their average annual per capita annual Gross National Product, in U.S. dollars.
131]Low income. Per capita income of less than $795.
4. Lower-middle income. Per capita income of $796-2,895.
5. Upper-middle income. Per capita income of $2,896-8,955.
6. High income. Per capita income over $8,956.
Table 1. Water Stress Category. Withdrawal to availability ratio
(population in millions of people)
Income Withdrawal/Availability 1995
1 (<10%). 2 (10-20%) 3 (20-40%) 4 (<40%) Total
1 806.18 1,265.89 957.70 238.07 3,267.84
2 542.40 285.95 165.33 137.91 1,131.59
3 258.95 13.10 137.30 63.44 472.79
4 108.44 514.41 181.25 19.74 823.84
Total 1,721.97 2,079.35 1,441.58 459.16 5696.06
Table 1. This grid shows how the 5.7 billion people in the world in 1995 were distributed in terms of their use of available fresh water, and by their income as measured in GNP. Over one-half the world falls in the low income category, and more than one-third of these people are in countries that already face medium-high to high water stress. An additional 39 per cent are in countries with moderate water stress. As well, one-fifth of the world is in the lower-middle income category. Of these, 31 per cent are in countries with medium-high water stress, and 24 per cent are in countries with moderate water stress. Unless water resources are managed with a view to achieving efficiency and equity, water shortages could become a serious obstacle to economic and social development in many poorer countries.
Figure 12. GNP per capita 1994 based on figures from the world bank.
I. Freshwater vulnerability
132] When water stress and income levels are combined, the result is a series of categories showing the vulnerability of various countries and regions to problems caused by water scarcities. Each of these could be sub-divided into a number of specialized categories, by water stresses and financial coping capability. For illustrative purposes, this report shows the effects on four broad categories.
1. High income countries with low water stress
133] Their main problem is water pollution rather than supply, although some large countries contain water poor regions. They have the financial resources to deal with regional water supply problems, often using water diversions.
2. High income countries with high water stress.
134] This category includes a number of countries that have fairly large amounts of water, but are facing stress conditions as a result of continuing over-use and pollution of their water resources causing problems, such as groundwater depletion, in the near future. Other countries have, however, already used most of their accessible water resources. They have little if any scope for increasing the amount of water supplied to human uses through conventional means without inflicting damage to aquatic ecosystems, or seriously depleting groundwater aquifers.
3. Low income countries with low water stress
135] There are several different types of countries within this grouping. There are low income countries that have low water stress because they have abundant water resources, primarily in tropical humid countries, or large countries that have a tropical region. Most of these countries or their humid regions suffer from too much water in the form of floods that come during a short rainy or monsoon season, causing damage to buildings, structures and agriculture. Since these countries are poor, they often suffer from inadequate drinking water supply and sanitation.
136] Another category, which includes much of Sub-Saharan Africa and some other countries in arid and semi-arid areas, has little water and little water stress because people are too poor to tap much of the resource. Overall, this grouping of countries suffers from inadequate access to its water resources due to insufficient financial resources, technical expertise and institutional support. Because of these constraints there is a lack of adequate water supply, sanitation and waste water treatment. In cases where there is high population growth or economic development, there is likely to be an increase in water demand. If that demand is not well managed, it could drive the country into a high vulnerability situation.
4. Low income countries with high water stress
137] This category is made up of low-income countries that are using their water resources heavily now, often for farm irrigation. They also suffer from a lack of pollution controls. A number of countries in the arid or semi-arid regions of Africa and Asia fall in this category. These countries are the most constrained for future development because they have neither the extra water nor the financial resources to shift development away from intensive irrigation and into other sectors that would create employment and generate income with which to buy food from water-rich countries.
II. WATER CHALLENGES - A 30 YEAR OUT-LOOK
138] In this section, the report draws a number of implications for future water use patterns, based on current trends. From 1995, it looks forward for 30 years, which is the span of a generation, examining major forces that will affect and be affected by water use. It is difficult to provide a detailed picture of the world of 2025 because of many uncertainties in political and economic developments. However, it is possible to look ahead, and provide some general analyses.
A. Driving forces of change
139] Water use in 2025 is going to be shaped by several major driving forces:
Population will influence how much water will be needed for a wide range of needs, including food production, industrial development and domestic use. The mid-range projection from the United Nations is that world population will grow from 5.7 billion in 1995 to about 8.3 billion in 2025, an increase of 2.6 billion people. Much of the population increase will be in the rapidly growing urban areas of developing countries, many of which are already experiencing serious water stress.
140] The magnitude of the impact of a given population will vary depending on the amount and patterns of consumption of natural resources and of pollution. Depending on what technologies are used, the impact from a given type of consumption can be increased or decreased from today's levels. For example, if more food is produced by increasing the amount of irrigation, using the same mix of technologies as today, the water use will increase. The same is true of the continuing industrial development. A UNIDO study showed that current trends will lead to a more than doubling of 1995 industrial water use by 2025, with over a four-fold rise in industrial pollution loading unless changes are made. If more water efficient technologies are used, this would cut wastage, and thus reduce the amount of water that needs to taken from various sources to produce a given amount of food or industrial output. In the agricultural and industrial sectors, there are already many examples of technology changes that have reduced both the amount of water used and the amount of pollution released without reducing the output of products. At the domestic level, there are many examples of water-efficient fixtures, and there are attempts to educate more people in the safe use of hazardous materials to reduce the amount dumped into waterways or drains leading to waterways.
141] Trade policies. A large part of the increase in world food demand will come from the arid and semi-arid developing world, where there are high population growth rates. Many of these countries will find it difficult to keep increases in food production in line with demand increases, and water will be a limiting factor. Countries may have to choose between using their scarce water resources to maintain food self-sufficiency, or to use the water to produce high value products that can be exported to pay for food imports.
142] Most of the new population will be found in the developing world, and those countries will move from being 37 per cent urban in 1995 to 56 per cent urban in 2025. At the same time, there is more industrial development. These trends take both people and water supplies from agriculture, and creating an urgent need for more urban sanitation. Peri-urban agriculture is also increasing. By 1995, the world had 321 cities with populations over 1 million, including 15 mega-cities with populations in the 10 to 20 million range. The number of mega-cities is forecast to double over the next 20 years. In spite of that, there will still be more rural poor in 2025. If regions with high rates of urbanization are to maintain current levels of water and sanitation supply, this could mean investments over 1 per cent of GDP by 2025.
Figure 13. This map shows locations of large cities of the world.
143] There is another potential factor that could affect water availability. According to the Intergovernmental Panel on Climate Change, the release of gases such as CO2 are increasing the ability of the atmosphere to trap heat. The panel warns that this may bring temperature increases, precipitation changes and sea level rise, with impacts varying on the availability of fresh water around the world. Computer models of possible future climate patterns are not yet precise enough to forecast changes at the local or small basin level. Current indications are that if climate change is gradual, the impacts may only be minor by 2025, with some countries having positive impacts, and most being negatively affected. Climate change impacts are predicted to become increasing strong during the decades following 2025.
B. Outlook and challenges that lie ahead
144] Although there is a very large uncertainty about future water needs, it is clear that all sectors will have growing requirements, and they already face stresses in many regions of the world. Given current trends, as much as two-thirds of the world population in 2025 may be subject to moderate to high water stress, and almost half the world would have clear difficulties in coping due to inadequate financial resources. Since many of the countries currently facing moderate to high water stress, as well as those that risk moving into higher stress categories by 2025 belong to the lower income groups, it is clear that water resources could become a limiting factor in the development of a number of countries. For reasons spelled out earlier in this report, it will also be more difficult and expensive to easily augment reliable water supplies by building more dams and creating reservoirs. There will be a need to modify consumption patterns, and to design and construct water supply projects in such a way as to bring into the planning both the people who may suffer and those who benefit, and to ensure that benefits are distributed fairly. Demand management will serve as an essential policy tool.
145] Many economic forecasts do not currently account for the amount water that will be required to achieve their goals, and water may become a limiting factor. Certain current water-intensive patterns of development will become less and less feasible.
146] As the risk of water stress increases, there will be a need for increased demand management in order to maximize the socio-economic benefits derived from the competing users of water. Water management must also be more prudent than in the past to avoid further degrading agricultural areas through such impacts as salinization, water erosion and waterlogging. Failure to protect the food growing capability of the world would have severe implications. To avert such problems countries, particularly water scarce countries, need to look at projections in such sectors as population, urbanization, economic and agricultural development, and establish water strategies and policies.
147] One of the trends identified in this report is that as water becomes more scarce in relation to demand, and competition among various users increases, water ceases to be available as a free good and in some cases becomes a tradable commodity. There is a shift taking place in the role of governments from being providers of water at very low cost, to regulators of water markets. As competition for available water grows among users, such as municipalities, industries, hydro-electric generators and irrigators, the price of water rises. While this allows the marketplace to choose the highest-valued use for water in economic terms, it will almost certainly mean water price increases, and this means that some users will be able to outbid others for the available water. This has the potential to impose hardships on some users, and there will be a need to ensure that everyone has a basic amount of water available at reasonable cost.
Figure 14. This map shows the impact of the expected population growth on water usage by 2025. It is based on the UN mid-range population projection and assumes that the current rate of use per person will not change. No account is taken of probable increases in water use patterns with economic growth or improvements in efficiency in water use.
1. Water needs for food production
148] World population forecasts suggest that within 30 years nearly 50 per cent more people than in 1995 will need to be fed. A substantial portion of future population growth is forecast for arid and semi-arid regions. Here, rainfed crop production is insecure because of a short rainy season, erratic rainfall, recurrent drought years, high evaporation of the rain that does fall and crust-forming, desertification-prone soils. In Sub-Saharan Africa, where over 95 per cent of the farmers depend on rainfed farming, the per capita production of cereals in the past two decades has not risen, and remains below what is needed to feed the population.
149] A number of estimates were made of how much water would be needed to produce enough food to give everyone in the world a healthy diet. The estimates ranged between a 50 to 100 per cent increase in water for food production over 30 years. The bulk of the increase in food production will need to come from irrigated land. Some of the estimates found that by 2025, it would require virtually all the economically accessible water in the world to meet the needs of agriculture, industry and households, and maintain adequate lake levels and flows in rivers. If more water is needed, more expensive projects such as high cost dams and diversions to bring water from sources far away from the area will be required.
150] As water becomes more scarce, municipalities and industries will be able to outbid most farmers, and this will push up the cost of water. If cost of water is passed on to consumer, food prices will go up. If farmers have to absorb the increased cost, poorer farmers growing relatively low value products could be forced out of business. While in the long run the use of pricing as a tool for allocating water resources is effective, the implementation of pricing policies need to take into account the possible economic and social impacts on the peri-urban and rural poor.
151] As food production is closely linked to the quality of land, the proper management of irrigation is essential in order to prevent land degradation such as salinization and waterlogging. The installation of adequate drainage, while protecting this natural capital, is likely to raise the cost of irrigation.
2. Water supply and sanitation and health
152] The regions most vulnerable to domestic water shortages include those that presently have poor access to water, and have rapid population growth, uncontrolled urbanization, financial problems and which lack of a skilled work force. Even if the world maintained the pace of the 1990s in water supply development, it would not be enough to ensure that everyone had access to safe drinking water by 2025. The challenge is particularly critical in Africa. Sanitation development is even more difficult to achieve. If everyone is to have sanitation facilities by 2025, this means providing services for more than 5 billion people in 30 years.
153] The continued neglect on the need for waste water treatment and damage from water pollution will lead to increases in public health problems and further damage to ecosystems, including the oceans, and foregone opportunities to recover and treat waste water for other uses, such as irrigation.
3. What will happen?
154] The analyses show that if many of the current approaches to water management to not change, this will lead to increasing water stress. As scarcities increase, there will be the risk of greater conflict over the water in the more than 300 transboundary rivers as well as many underground aquifers. This shows the importance of cooperation over river systems shared by countries. It will be crucial to work out water sharing arrangements which seeks to maximize benefits for all users.
155] Since it typically takes at least a decade to bring even a modest water resources project from planning to completion, and even more time for large projects, it is crucial for decision makers to immediately make and implement water policies and programs based on the best evidence available.
156] The concluding section provides suggestions for development of global, regional and national water strategies.
III. CONCLUSIONS AND POLICY OPTIONS
A. Elements of a water strategy - general considerations
157] Although many current water use patterns and pollution habits are sending the world toward a series of local and regional water crises, mankind have not yet crossed the line of no return. There are many practical, cost effective measures that can reduce the strain on water resources. They represent a series of critical investment opportunities that cannot afford to be ignore.
158] It is crucial for water resources to be given a high priority in planning. There are some promising national efforts in water policy development, but these efforts must be spread and reinforced. Governments must reduce the fragmentation of institutional responsibilities on water issues. They also need to include water resources in economic analysis.
159] Acritical element in planning is information on the state of the water resources. Over recent decades the ability of many countries to assess water resources has actually declined because measurement networks and staffing levels have been reduced.
160] Since it will take time to change many unsustainable development patterns, urgent and decisive action must begin now. Experience has shown that the consequences of inaction, in terms of human suffering, social disruptions, foregone economic opportunities and the cost of undoing the harm caused to the resource and the environment will usually outweigh the human and financial resources needed in to engage into a sustainable development path. Many of the problems are of a local and regional nature, and action is primarily a national (and regional) responsibility. Nevertheless, it would be illusory to believe that anything short of a global commitment would provide the means to sustainability. Because some of the water crises could be very severe, the whole world has a stake in averting them.
1. Making water available to increase food production
161] The need and demand for food are rising steadily both because of steady population increases. A large amount of the world production of grains is used for meat production in developed countries and as the diet in developing countries gets fuller and more balanced, an increased demand for animal proteins is expected. This growing demand for meat means that more water will be needed since meat requires more water to produce than a vegetarian diet.
162] In many regions, water scarcity is resulting in severe constraints to the expansion of agricultural production, thus raising pressure for water policy interventions and for more efficient water use practices. Because globally little new land of adequate quality remains to be put into production, and whereas the environmental cost of converting land use is high, the largest part of future food requirements will have to be satisfied through higher productivity on existing agricultural land. Application of water through various forms of irrigation, jointly with the use of genetically improved crops and the considered application of pest management and plant nutrition systems, are main factors of the required agricultural productivity increases to feed the world. Countries can improve the efficiency of water use for irrigation with such techniques as lining canals and the use of more efficient ways of applying water to plants. However, attention must be drawn to the fact that water use in the entire river basin can be highly efficient even though the individual irrigation schemes within the basin are inefficient, in which case seeking a higher irrigation efficiency in one scheme is bound to result in further water scarcity in the downstream schemes. Under such situations, water savings have to be sought in the use of a less water demanding mix of crops and in shifts of the cropping period into a less evaporation-intensive season.
163] Besides new cropping patterns and conventional first-generation irrigation, many other "drought-proofing" techniques exist. They include high-efficiency irrigation, water harvesting, inland valley swamp development, low-lift pump schemes, peri-urban irrigation with treated urban waste water and conjunctive use of surface water and groundwater. Irrespective of what method is chosen, it would imply a consumption of water now passing through the landscape, meaning that water would not be available downstream for other uses.
164] If treated waste water is used for irrigation, it will mean that the amount of fresh water that could be used for other purposes would increase. In those water scarce countries that, because of the domestic water shortage will become heavy importers of basic food stuff, wastewater may well represent in the future the predominant long-term water supply for irrigated agriculture. Water harvesting, which means small-scale projects to capture runoff, can also improve soil moisture and food production.
165] Desalination of seawater is an option for such relatively low-volume, high-value, users as industries and homeowners with at least a moderate income. But, even with technological advances, wheat production with desalinated water is economically prohibitive.
166] As water prices rise, small scale farmers will face increasingly difficulties competing for the scarce water resources. There may thus be a need to help the small irrigation farmer, particularly with partnerships that will give them access to capital, technology, know-how and markets.
167] However, there are limitations to how much these techniques will improve the situation, especially in arid countries. Countries may have to turn toward increasing food imports, as is already the case for a number of arid countries, particularly in the Middle East and North Africa. Countries may have non-economic reasons to pursue a course of substantial food self-sufficiency. From an economic point of view, they may find it advantageous to shift their production pattern toward less water-intensive and higher income-yielding products, either in agriculture or the industrial sector. This transition is already taking place in a few countries. In Israel, the water use within various sectors is very efficient. Water availability is, however, so limited that allocation choices between sectors competing for the water resources are increasingly necessary. In this situation, the previous high priority to irrigation is reduced and urban users are pronounced. In most countries, this shift will require training of the rural population to acquire skills needed in other sectors of the economy, and an infusion of capital to create new economic opportunities.
168] The world needs to move towards achieving the objective of global food security. In some countries, this could be done through a transition from food self-sufficiency (a capacity to produce all food within the country) to food self reliance (a capacity to provide food from national sources and through purchase from the international market). However, such an integration of the world economy is unlikely to be painless without proper consideration of world market conditions, and the potential impact on the poorer strata of the population of developing countries. Countries can only make such transition if they can rely on the world agricultural markets to provide a dependable and efficient source of supplies at stable international prices.
2. Access to drinking water supply and sanitation need to be increased dramatically
169] Without adequate quality and sufficient quantities of water for human consumption and for personal and domestic hygiene, billions of people will continue to suffer from diarrhoea and enteric diseases, helminthic infections and other illnesses arising from unsanitary environments, improper excreta disposal and polluted water. Even though most of the suffering takes place in developing countries, the whole world will suffer. Diseases can be communicated easily over long distances. Economic stagnation resulting from ill health affects the global economy.
170] There are a number of relatively simple and inexpensive techniques for supplying drinking water and sanitation. If they are to succeed they must be chosen in consultation with the users, and they must use technologies that can be installed and maintained at the community level. They must thus be user friendly, affordable and appropriate.
171] Top priority needs to be given to the African region, Latin America and South-east Asia. Recent estimates are that $54 billion would be needed between 1990 and 2000 to provide universal coverage only in the urban areas of the regions most in need. The resources required are more than three times the rate of present expenditure. There is no sign this amount of funding will be made available in the near future in the form of reallocation of internal government spending in nations, or in development assistance from abroad. Experience shows that in many cases additional funding for water supply and sanitation systems could be raised by charging users even modest amounts of money for the water they draw. Countries need to apply a higher degree of demand management.
172] When it comes to making decisions on water supply and sanitation systems, it is vital to involve all users. For example, women already play a crucial role in providing water and in decision on hygiene in families. They should be closely involved in decision-making as well as implementation of the water and sanitation supply programmes.
3. Water pollution must be reduced to protect human health and the rest of the environment
173] If not controlled, untreated sewage from cities, industrial discharges and non-point pollution from agricultural activities and urban runoff will continue to damage rivers, aquifers and coastal zones, with devastating effects on our freshwater resources and oceans. Even though pollution prevention sometimes has a higher initial cost than discharging wastes untreated, experience shows that in the long run it is cheaper than clean-ups. Waste water, especially that which is not heavily polluted, can often be used for other purposes, such as industrial cooling and sometimes for irrigation. To encourage pollution prevention, it is important to apply the Polluter Pays Principle.
174] It is important to build on the water quality management experiences of different regions. For example, Nigeria has Interim National Water Quality Guidelines and Standards that are used to set water quality standards. The United States and Canada have adopted controls on discharges that take into account the effect on downstream ecosystems, such as the Great Lakes. Canada looks at impacts on the marine environment when setting water quality objectives for rivers flowing directly to the seas.
The need for cooperation is clearly demonstrated for transboundary waters
175] Some of the world's more than 300 major river basins and a number of major aquifers that cross national boundaries are in regions where serious water quality or quantity problems are or soon will be evident. A wide range of transboundary water agreements exist, dealing with rivers, lakes and other water bodies. While a number of these agreements refer to river basins, most of them deal with specific waterworks, water uses and measures to control and regulate water flows. A few deal with pollution. In 1995, a Protocol was signed by the eight heads of member governments of the Southern African Development Community on regionally shared watercourses. The member states recognized that a failure to develop water resources in a sustainable manner could hamper economic productivity and social development in the region. The agreement promotes the equitable use of shared water resources, including the development of integrated water resource development plans. The Rhine Action Plan has led to pollution control objectives that are to improve water quality to the point that sensitive species can once again live in the river. It is also aimed at reducing pollution to the North Sea. The 1909 Boundary Waters Treaty between Canada and the United States has led to a series of agreements over the sharing of waters and controls on pollution, particularly in the Great Lakes.
176] The need for a comprehensive legal instrument for international water bodies has been voiced by several countries. The Draft Articles of the Law of the Non-navigational uses of International Watercourses were adopted by the International Law Commission in 1994. The Commission recommend the elaboration of a convention by the General Assembly on the basis of the draft Articles.
177] This report, like many others before it, has identified the river basin as the logical unit for water management, as any activity in one part will influence other parts of the basin, especially downstream. Thus, there is a clear need for cooperation in the management of international and transboundary watercourses to maximize mutual benefits for all riparian countries.
. Water needs to be considered as a resource having an economic value
178] Water has economic value, and should be considered an economic as well as social good. Like any valuable commodity, water use has a cost either in terms of its development or foregone opportunities. The cost of using or misusing water does not disappear, but is paid either by the user or by the community at large or through a depletion of the existing natural capital. As water demands increase, it becomes more important to see that water is put to the high-valued economic uses. It is important to see that there is full cost accounting, full cost recovery for the provision of water, and that users pay for the water used for economic purposes.
179] At the same time, it is essential for water planning to secure basic human and environmental needs for water. Otherwise, there will be a risk of shortages, which impose costs on society both in terms of health impacts and losses in economic performance. An example is Brazil which is undergoing social reform programmes, including in the water sector. The country still needs to settle some controversial issues, but the direction is toward a recognition of water as an economic good while also stressing that provision for human consumption must be given top priority.
180] There is a need in many countries to begin or to continue a shift from the government from being the provider of water services to being the creator and regulator of an environment that allows involvement of communities, the private sector and non-governmental organizations in the provision of water supply and sanitation services as well as in the development and utilization of water in other sectors of the economy. Uganda is undergoing water reforms and is moving away from a centralized system to a system where communities will actively take part in the decision making and where choices of solution to water services will relate to local affordability and needs. Thus, the new Water Action Plan and Water Statue aim to facilitate a flexible and coherent water resources management at all levels in the society.
181] The introduction of water markets and pricing mechanisms can encourage the private sector to play an increasingly important role in providing the necessary financial resources and management skill needed for the successful development and utilization of the resources. Governments need to establish laws and regulations for the fair and efficient operation of water markets. Wherever subsidies or income transfers are deemed necessary for social or other national considerations, the objectives of such subsidies or transfers should be well defined and the incidence of the subsidy should not fall on the public or private utilities providing the service.
182] It is essential that economic planning incorporate the idea of water as natural capital whose services can be depleted, as in using up groundwater or polluting water sources. Those services can only be restored at high cost. In the long run, a failure to include the state of water resources in economic analysis, particularly in macro-economic analysis, leads to unnecessary, wasteful and costly investments in water supply developments, mis-allocation of water resources among competing uses and, in some cases, to the actual collapse of schemes.
. Building human and institutional capacity to solve our water problems
183] Capacity building is an essential step in preparing sustainable water strategies. It includes education, awareness-raising and the creation of a legal framework, institutions and an environment which enables people to take well-informed decisions for the long-term benefit of their society. Women, youth, non-governmental organizations and indigenous people need to be brought into capacity-building strategies, as they are essential in building a sustainable water future.
184] If people, particularly in poor and water scarce countries are going to come up with solutions to problems such as how to attain food security, they must be educated and given access to the information that will help them make the decisions. The world needs more well-trained people, especially more women, to assess and develop fresh water supplies, and to manage water projects for sustainable use. Capacity building should be aimed at giving professionals from different backgrounds and working in different sectors the skills to effectively participate in the intersectoral dialogue during the planning, design and construction of water resources projects. There is further a need to create new or strengthen existing institutions capable of integrated water management and to build networks linking institutions with expertise in land, water quality and water quantity.
185] Many governments will need to assign a high priority to their capacity-building efforts towards institution building, legislation, and human resources development. National efforts in this regard need to be supported by international, regional and national external support agencies, and by the non-governmental community, including the private sector.
. Access to reliable data is presently inadequate
186] Effective water resources assessment and management are not possible without adequate information, including hydrological information, water use and quality data, demographic data (separated by gender where relevant), forestry and land management, and capacity to assess the data. There is a need for national and internationally agreed upon and harmonized information systems that provide data needed for decision making, as well as common ways of analysing the information.
187] Ideally, the river basin or watershed should constitute the geographical unit for data collection and analysis. Even though some countries have hydrological data available, usually on river basin level, almost no country has socio-economic data sorted at a comparable level.
188] The experience with the current assessment demonstrates that the capability to provide accurate water quantity and quality data is sorely lacking in the majority of countries. For years, the capacity of hydrological offices in many developing countries, particularly in Africa, has been declining when it comes to the operation, maintenance and extension of hydrological networks. Few, if any, developing countries have a significant capability for water quality monitoring, which would give important information from a health perspective. It is very difficult to obtain reliable, systematic information on water resources management and irrigation in most developing countries. There is also poor data on land degradation related to water use. Even developed countries have been reducing their environmental monitoring systems as part of general budget cuts in recent years. Despite problems in finding resources for data gathering, there have been some encouraging signs. As part of the Southern African Development Community protocol on water resources, there was agreement to create a Water Sector dealing with integrated water planning and development of shared river basins. India's National Water policy calls for the development of a standardized national information system with multi-disciplinary units for water management.
189] Support from international, regional and national external support agencies is urgently needed. The WHYCOS programme, developed by WMO with support from the World Bank and other donors, is an important first step with regard to the strengthening of hydrological networks. The UNEP/WHO/GEMS water programme provides international support for the monitoring of water quality. The WHO/UNICEF Global Drinking Water Supply Monitoring Program collects and analysis information involving water supply and sanitation coverage in developing countries. FAO's AQUASTATs programme assembles information on rural water use in participating countries, and make it available in a standard format. UNESCO's International Hydrological Programme includes the FRIENDS (Flow Regimes of International Experimental and Network Data Sets) programme that places a strong emphasis on water resources management. Despite these important programmes, international support efforts concerning information management remain fragmented and incomplete.
B. Strategy development
190] Important action recommendations on global water issues have been formulated, from the 1977 United Nations Water Conference in Mar del Plata and the Global Consultation on Safe Water and Sanitation for the 1990s in New Delhi, India, 1990, to the International Conference on Water and the Environment in Dublin, and the United Nations Conference on Environment and Development, both in 1992. Further recommendations were provided by Interministerial Conference on Drinking Water Supply and Environmental Sanitation in Noordwijk, and by the Commission on Sustainable Development at its second session, both in 1994. Considerable progress has been achieved in some places in terms of implementing these recommendations, with significant achievements towards a more equitable and efficient utilization of water resources. On the whole, however, we are still far from achieving the sustainable development objective.
191] The findings of this report dramatize the importance of putting into practice the concept of a holistic management of fresh water as a finite and vulnerable resource, and the integration of sectoral water plans and programmes within the framework of national economic and social policy.
192] Through a series of meetings, particularly the Dublin water conference, a set of principles, later reflected in chapter 18 of Agenda 21, for water planning and management have emerged and are gaining wide acceptance.
The Dublin Water Principles
Principle No. 1. Fresh water is a finite and vulnerable resource, essential to sustain life, development and the environment.
Principle No. 2. Water development and management should be based on a participatory approach, involving users, planners and policy-makers at all levels.
Principle No. 3. Women play a central part in the provision, management and safeguarding of water.
Principle No. 4. Water has an economic value in all its uses, and should be recognized as an economic good.
193] The concept of water as an economic good needs to be implemented taking into account the provision of water for the satisfaction of basic needs.
194] Some important progress has been achieved in a number of countries in this regard. However, a much greater commitment to the implementation of these recommendations is needed world wide to achieve sustainability.
195] Governments should incorporate these important principles in their social, economic, and environmental planning.
C. Policy option for country categories
196] Given many current trends, there is a risk that an increasing number of low income countries will find themselves facing water stress. Some countries may also have economic growth that will shift them to higher income categories, giving them financial means to develop suitable water strategies. It should be noted that some economic growth projections used by planners do not take into account water as a possible limiting factor in future economic development.
197] As the pressure on water increases, so will the number of problems that countries must solve. For a country not to move to a position of higher water stress possibly with serious economic implications, certain actions must be taken, and most of them are urgent if they are not to suffer a decline in their human, economic and environmental health.
198] Relatively small amounts of water per capita do not prevent development, but they do shape it. There are examples of countries that are coming to terms by using technology and economic strategies to live within their means.
199] All countries need to implement the recommendations contained in the Rio Declaration and in chapter 18 of Agenda 21 in the framework of their water management policies. They should also encourage demand management and pricing principles, as discussed above.
200] At a time when development assistance funds are limited, it will be important to focus on assisting people who suffer from lack of funds to make use of their water resources. This must be done in a way that helps economic and social development without over exploiting water and other natural resources. After the provision for basic human needs, development projects in most countries need to focus on efficient use of water for relatively high value products.
. High income countries with low water stress
201] Pollution reduction and control is the major water-related challenge facing most countries in this category. Many of them also need to look at the issue of water pricing, because the fact that water might be plentiful does not mean that it should be free. Development and distribution costs need to be covered by either public or private utilities. Some countries in this group, with favourable land and climate conditions, may have a significant potential for increased food production from irrigation and rainfed agriculture, and could play a significant role in providing food to world markets.
202] Because of the average nature of the water availability and use, some large countries classified in this category nevertheless contain arid and semi-arid areas which would have to be considered as being highly stressed and vulnerable. In such regions, demand management measures and water rights markets are becoming critically important.
. High income countries with high water stress
203] For those countries with low per capita water availability, the allocation of water to the highest value uses is a necessity. Demand management and water allocation policies designed to maximize the socio-economic value of water are of paramount importance, as is pollution control. Water markets with tradable water rights and permits are already beginning to play an important role in the allocation of water, and will need to continue to play an increasingly important role. With increased allocation efficiency, it is likely that irrigated agriculture will decrease in importance, and it appears that more countries in this category will become increasingly dependent on the world market for agricultural products.
204] The depletion of groundwater aquifers and sea-water intrusion needs to be avoided. The protection of surface and groundwater from pollution is vital. It is recommended that all countries in this category give urgent attention to pollution monitoring and control through economic and regulatory measures of both surface and groundwater.
205] Waste water treatment and reuse will constitute essential mechanisms for pollution control and the augmentation of water supplies. For example, Israel already recycles and reuses two-thirds of the water discharged after urban and industrial use.
. Low income countries with low water stress
206] Countries in this group that are well endowed with land and water resources may have the opportunity to increase agricultural production and exports into the world market either from irrigated or rainfed agriculture. For those countries with relative water scarcity, and high levels of evaporation, agricultural production is probably best directed into high-value, low water intensive products. Some poor countries lack adequate access to what little water they have, and development assistance could help them in using that water wisely.
207] Both water rich and water poor countries with low incomes generally suffer from a lack of sanitation and waste water treatment. Water pollution from human or animal wastes is often already a problem, and steps are needed now to improve pollution control and treatment to protect human and ecosystem health.
208] The acceptance of highly polluting industries with little or no control on their discharges may be tempting on the basis of short-term economic growth considerations. However, the overall, long-term costs to redress environmental damages resulting from such decisions have often been shown to more expensive than creating low-polluting industries in the first place.
209] Countries are urged to give high priority to investments for waste water treatment and reuse, and to formulate and implement pollution monitoring and control policies.
. Low income countries with high water stress
210] If appropriate action is not taken between now and 2025, the number of people in this category could grow substantially. Water resources will become a major limiting factor to socio-economic development unless early measures are taken towards restructuring production and consumption patterns away from wasteful and low value water intensive uses. There is evidence that some countries are already reaching this kind of developmental bottleneck. Achieving sustainable use of water resources for most countries in this category will require that per capita water use decrease as population increases.
211] Given the high ratio of water use to availability, population growth and future economic development will require shifts in the utilization of water towards the production of high value products. Under current trends, many of these countries will become less self sufficient in food production, and will have to rely on the world market for food imports. The economic transformation of these countries will need to be accompanied by social support programmes involving education and training of the labour force to enable it to cope with the demands of an increasingly industrialized society.
212] Countries in this category are urged to give the highest priority to the formulation of economic and regulatory measures designed to increase irrigation efficiency and optimize water allocation among various uses. In particular, they need to pay attention to the generation of foreign exchange that might be needed for food imports.
213] Countries should increase waste water treatment and reuse, and should control pollution from agricultural chemicals through land management and integrated pest management measures.
214. These countries may need to adopt the following strategies:
o Develop the educational and information infrastructure to improve the skills of the labour force required for the industrial transformation that need to take place.
o A need to shift to more high-valued less water-intensive crops, and develop the associated agricultural industries to process more of the products, thus raising the valued-added component in their countries.
215] To be able to move out of this category in the next 30 years, assistance of the international community will be needed in order to generate the financial resources for the economic transformation required.
D. Action - recommendations
216] Bearing in mind existing principles and the recommendations in chapter 18 of Agenda 21, the following action are recommended partly based on the discussion in previous sections of this report:
217] Manage water quantity and quality together in an integrated and comprehensive manner, taking into account the upstream and downstream consequences of management actions, regional and sectoral relations and social equity.
218] Base strategies for the sustainable development of water resources on a participatory process that integrates all aspects freshwater management.
219] Provide equitable access to clean water for all people and include human health and the state of the environment as water resource management indicators.
220] Develop sustainable water strategies that address basic human needs, as well as the preservation of ecosystems, in ways that are consistent with socio-economic objectives of different societies.
221] Develop adequate national and regional water policies and plans, and promote cost-efficient water technologies. Water management must be integrated into physical, social and economic planning, including land use planning, forest resource utilization and protection of coastal zones from land based activities. Land and water use are closely intertwined.
222] Integrate water in economic planning analysis. Recognize water and the environment as vital capital. This means accounting for the value of water in each nation's system of national accounts. The accounts need to reflect the economic losses caused by a degradation of water resources.
223] Integrate the private sector into the water development process. While people must be provided with access to water for basic needs at affordable cost, the private sector can play a helpful role in seeing that water for a number of industrial and agricultural uses is priced in a manner that reflects its value to society.
224] Build up needed expertise on water issues among water users and decision-makers at all levels, thus increasing their capacity to deal with complex water management questions. There is a need for people with expertise in hydrology, water quality, water law, water conflict resolution, and people who can identify and help implement the best water technologies. It is essential also to build expertise on dealing with the socio-economic aspects of water management, such as water pricing, and the role of the private sector in water supply and sanitation.
225] Enhance national water resource assessment capabilities and measurement networks and establish water resource information systems that enable people to understand the options available for sustainable urban, industrial, domestic and agricultural development in combination with environmental conservation.
. High income countries with low water stress
201] Pollution reduction and control is the major water-related challenge facing most countries in this category. Many of them also need to look at the issue of water pricing, because the fact that water might be plentiful does not mean that it should be free. Development and distribution costs need to be covered by either public or private utilities. Some countries in this group, with favourable land and climate conditions, may have a significant potential for increased food production from irrigation and rainfed agriculture, and could play a significant role in providing food to world markets.
202] Because of the average nature of the water availability and use, some large countries classified in this category nevertheless contain arid and semi-arid areas which would have to be considered as being highly stressed and vulnerable. In such regions, demand management measures and water rights markets are becoming critically important.
. High income countries with high water stress
203] For those countries with low per capita water availability, the allocation of water to the highest value uses is a necessity. Demand management and water allocation policies designed to maximize the socio-economic value of water are of paramount importance, as is pollution control. Water markets with tradable water rights and permits are already beginning to play an important role in the allocation of water, and will need to continue to play an increasingly important role. With increased allocation efficiency, it is likely that irrigated agriculture will decrease in importance, and it appears that more countries in this category will become increasingly dependent on the world market for agricultural products.
204] The depletion of groundwater aquifers and sea-water intrusion needs to be avoided. The protection of surface and groundwater from pollution is vital. It is recommended that all countries in this category give urgent attention to pollution monitoring and control through economic and regulatory measures of both surface and groundwater.
205] Waste water treatment and reuse will constitute essential mechanisms for pollution control and the augmentation of water supplies. For example, Israel already recycles and reuses two-thirds of the water discharged after urban and industrial use.
. Low income countries with low water stress
206] Countries in this group that are well endowed with land and water resources may have the opportunity to increase agricultural production and exports into the world market either from irrigated or rainfed agriculture. For those countries with relative water scarcity, and high levels of evaporation, agricultural production is probably best directed into high-value, low water intensive products. Some poor countries lack adequate access to what little water they have, and development assistance could help them in using that water wisely.
207] Both water rich and water poor countries with low incomes generally suffer from a lack of sanitation and waste water treatment. Water pollution from human or animal wastes is often already a problem, and steps are needed now to improve pollution control and treatment to protect human and ecosystem health.
208] The acceptance of highly polluting industries with little or no control on their discharges may be tempting on the basis of short-term economic growth considerations. However, the overall, long-term costs to redress environmental damages resulting from such decisions have often been shown to more expensive than creating low-polluting industries in the first place.
209] Countries are urged to give high priority to investments for waste water treatment and reuse, and to formulate and implement pollution monitoring and control policies.
. Low income countries with high water stress
210] If appropriate action is not taken between now and 2025, the number of people in this category could grow substantially. Water resources will become a major limiting factor to socio-economic development unless early measures are taken towards restructuring production and consumption patterns away from wasteful and low value water intensive uses. There is evidence that some countries are already reaching this kind of developmental bottleneck. Achieving sustainable use of water resources for most countries in this category will require that per capita water use decrease as population increases.
211] Given the high ratio of water use to availability, population growth and future economic development will require shifts in the utilization of water towards the production of high value products. Under current trends, many of these countries will become less self sufficient in food production, and will have to rely on the world market for food imports. The economic transformation of these countries will need to be accompanied by social support programmes involving education and training of the labour force to enable it to cope with the demands of an increasingly industrialized society.
212] Countries in this category are urged to give the highest priority to the formulation of economic and regulatory measures designed to increase irrigation efficiency and optimize water allocation among various uses. In particular, they need to pay attention to the generation of foreign exchange that might be needed for food imports.
213] Countries should increase waste water treatment and reuse, and should control pollution from agricultural chemicals through land management and integrated pest management measures.
214. These countries may need to adopt the following strategies:
o Develop the educational and information infrastructure to improve the skills of the labour force required for the industrial transformation that need to take place.
o A need to shift to more high-valued less water-intensive crops, and develop the associated agricultural industries to process more of the products, thus raising the valued-added component in their countries.
215] To be able to move out of this category in the next 30 years, assistance of the international community will be needed in order to generate the financial resources for the economic transformation required.
D. Action - recommendations
216] Bearing in mind existing principles and the recommendations in chapter 18 of Agenda 21, the following action are recommended partly based on the discussion in previous sections of this report:
217] Manage water quantity and quality together in an integrated and comprehensive manner, taking into account the upstream and downstream consequences of management actions, regional and sectoral relations and social equity.
218] Base strategies for the sustainable development of water resources on a participatory process that integrates all aspects freshwater management.
219] Provide equitable access to clean water for all people and include human health and the state of the environment as water resource management indicators.
220] Develop sustainable water strategies that address basic human needs, as well as the preservation of ecosystems, in ways that are consistent with socio-economic objectives of different societies.
221] Develop adequate national and regional water policies and plans, and promote cost-efficient water technologies. Water management must be integrated into physical, social and economic planning, including land use planning, forest resource utilization and protection of coastal zones from land based activities. Land and water use are closely intertwined.
222] Integrate water in economic planning analysis. Recognize water and the environment as vital capital. This means accounting for the value of water in each nation's system of national accounts. The accounts need to reflect the economic losses caused by a degradation of water resources.
223] Integrate the private sector into the water development process. While people must be provided with access to water for basic needs at affordable cost, the private sector can play a helpful role in seeing that water for a number of industrial and agricultural uses is priced in a manner that reflects its value to society.
224] Build up needed expertise on water issues among water users and decision-makers at all levels, thus increasing their capacity to deal with complex water management questions. There is a need for people with expertise in hydrology, water quality, water law, water conflict resolution, and people who can identify and help implement the best water technologies. It is essential also to build expertise on dealing with the socio-economic aspects of water management, such as water pricing, and the role of the private sector in water supply and sanitation.
225] Enhance national water resource assessment capabilities and measurement networks and establish water resource information systems that enable people to understand the options available for sustainable urban, industrial, domestic and agricultural development in combination with environmental conservation.
226] Pay attention to the role of gender in water resources management. In much of the world, women play a key role in acquiring water and deciding how it is used. They need to be part of the decision making process for water projects and for industrial and land use projects that affect water quality and quantity.
227] Accelerate or initiate actions that will result in global, international or regional agreements or programmes to address:
o The provision of safe drinking water and environmental sanitation.
o Elimination of unsustainable uses of toxic materials, especially Persistent Organic Pollutants.
228] Accelerate actions within the framework of existing programmes, conventions and agreements towards:
o The combatting of desertification and drought, by better integrating land and water management.
o The protection and sustainable use of biodiversity related to fresh water.
o The protection of coastal areas and oceans from land based activities.
229] Develop models of cooperation aiming at maximizing the benefits from the development of transboundary river basins or aquifers.
230] Accelerate the implementation of the water related activities contained in the Action Plans adopted at the:
o Conference for Small Island Developing States, Barbados, 1993.
o International Conference on Population and Development, Cairo, 1994.
o Fourth World Conference on Women, Beijing, 1995.
o Habitat II Conference, Istanbul, 1996.
231] Within the framework of the World Food Summit Plan of Action, approved by the World Food Summit in Rome in 1996, examine and report on water related activities aiming at securing access to food.
232] Develop an institutional and regulatory framework to ensure functional water markets and protection of water rights.
233] Establish, within existing institutions, especially the UN system, a global water information network to compile information with particular emphasis on water quality, quantity and water use. The institutions should also conduct regular global and regional water assessments. Water information programmes should be implemented at national level, and international institutions should propose models to ensure compatibility between data of individual countries. There is a need for a periodic review and it is recommended that the Commission on Sustainable Development carry out periodic global fresh water assessments, using the existing network of experts.
234] Build on international collaborative arrangements such as the Global Water Partnership, the Water Supply and Sanitation Collaborative Council, World Water Council, and strengthen collaboration with Non Governmental Organizations.
235] Develop north-south academic partnerships to develop the research capacity on a broad range of water-related issues, including those of quantity and quality and those related to helping people understand the value of water as natural capital.
236] Develop partnerships with the private sector and industries to take advantage of their expertise to achieve mutual benefits in the water sector.
237] Given the seriousness of the situation and future risk of crises, there is an urgent need to act now. The international community has to strive for a situation in which there is no undermining of the natural resource base. Land and water need to be protected from long-term degradation that threatens food production, aquatic ecosystems, human health and biodiversity. There is a need to reduce water use per unit of production, using water-efficient technologies. Pollution has to be sharply reduced, and persistent toxic substances that accumulate in the food chain must no longer be released into the environment. Agricultural water use has to become highly efficient, so as to ensure an adequate food supply for everyone. Generally accepted political goals need to be developed based on the fair sharing of benefits from water use.
In order to achieve this future it is necessary for governments to take the steps needed to reach a Global Consensus over and above what is contained in the existing principles and agreements on freshwater resources of the world. Such a Consensus should take into account factors brought out in this report.
238] Large Scale Dew Collection as a Source of Fresh Water Supply
Published in Desalination, Vol. 36, No. 3, March 1981, pp 299-306
Anil K. Rajvanshi1
Director, Nimbkar Agricultural Research Institute (NARI)
Phaltan, Maharashtra, INDIA
ABSTRACT
A scheme for large scale dew collection as a source of fresh water supply is outlined in
the present paper. The scheme envisages bringing cold sea water (50C) from about 500 meters
depth and about 5 km from the shore, in four, 1.22 m diameter plastic pipes. It then passes
through an onshore heat exchanger field with an area of 1.29 X 105 m2 (1.39 X 106 ft2) where it
condenses 643 m3 of dew over the 24 hour period. The pumping of sea water from the sea and
through the field is accomplished by three 200 kW wind machines. Technical and economical
feasibility of the scheme is analyzed and the possibility of marine culture as a source of food is
explored. The present scheme is economically not feasible as compared to a RO (reverse
osmosis) facility of equivalent capacity.
CONCLUSIONS
The following conclusions can be drawn based on the present study.
1. Large scale dew collection near the seashore for production of fresh water is technically
feasible.
2. A heat exchanger field of area 1.29 X 105 m2 (1.39 X 106 ft2) can condense 643 m3 (170,000
gallons) of dew over a period of 24 hours.
3. The cold water for dew condensation is obtained from a depth of about 600 m. The
pumping of 8.32 X 106 kg/hr (18.3 X 106 lbs/hr) of this cold water is achieved by 3, 200 kw wind machines.
4. This present scheme is economically not feasible as compared to a RO facility of equivalent
capacity.
239] Facts & Figures on Fresh Water
The State of the Planet's Fresh Water Supply
· Water covers close to three-quarters of the Earth's surface, but only a fraction of it is fresh water not locked in ice. South America accounts for about half of our planet's fresh water supply. Asia gets almost one-quarter. The remaining quarter is used by everyone living in North and Central America, Europe, Australia, Africa, and the Middle East.
· Most of the water we use goes to growing food: irrigation siphons off roughly two-thirds of all we consume. Industrial and other economic activities draw less than a third. Common household uses, most of which are low quality, such as watering lawns and flushing toilets, account for what is left. Men and women use water differently: men tend to use water for irrigation and other enterprises; women tend to use it for household purposes.
· Water is often distributed inequitably by class, gender, and even ethnic group. To make matters worse, the poor generally pay more for water than do the rich.
· All the best and cheapest sources of water are now being used. In some regions, we are approaching the limits: in the Middle East, 58% of all reasonably available fresh water is already being withdrawn. In Eastern Europe, the figure stands at 41%.
· Other strategies to increase water supply, such as desalinating seawater or shipping large volumes by pipeline or sea, are technically feasible, but they are complicated and expensive and would likely entail severe ecological and political costs.
· For more and more people, water quality is every bit as threatening as the lack of adequate supplies. Already more than 1 billion people do not have access to safe drinking water and 3 billion lack access to basic sewerage systems.
240] Options for the Future o ensure supply of fresh water
· The cheapest, most efficient way to increase the supply of fresh water is by managing its demand: reducing waste and making every drop serve more purposes, more efficiently.
· Past approaches that favoured large-scale, capital intensive projects did deliver water to many households and many farms, but most fell short of their original promise.
· Thirty years of applied research supported by Canada's International Development Research Centre (IDRC) offers a new focus for global efforts to curb water demand and alleviate poverty: community-based or local water management.
· Experience around the world shows the following:
o Scarce water supplies are used more sustainably if they are managed locally.
o Local management empowers people, particularly the poor and disadvantaged.
o Local management generally looks to more traditional rather than new solutions.
o Local water systems must be managed within frameworks linked to watershed management and to senior levels of government.
o Local management works best when policymakers can draw upon the lessons of field research when making decisions.
· Approaches to local water management that have proven effective
include
o Small-scale water supply, such as rainwater collection;
o Wastewater treatment and reuse, to improve sanitation and provide water suitable for irrigation;
o Community-based water quality testing, to allow isolated rural communities to monitor their drinking water supplies;
o Watershed management and irrigation, to improve soil productivity and reduce the considerable waste from irrigation.
241] How a Stream Becomes a River
The journey from stream to ocean begins in our backyards and farms.
Precipitation comes down, literally, everywhere -- in various forms. It may rain, hail, snow or sleet. Whatever the form, once it reaches the ground some water is absorbed by trees and other plants.
Once the water finds its way into a stream or ditch, where does it go?
If you have ever studied a map in detail, you will notice how rivers and streams form a network of waterways across the countryside.
Little streams come together to form small rivers. Small rivers join together and become medium-sized rivers. All these rivers may be tributaries of a large river. such as the Mississippi. Collectively, the network of rivers and streams form a watershed which drains the land of excess water
242] Nature should always be secured against degradation by warfare or other hostile activities.
Activities which might have an impact on nature shall be controlled, and the best available
technologies that minimize significant risks to nature or other adverse effects shall be used; in
particular:
· Activities which are likely to cause irreversible damage to nature should be avoided;
· Activities which are likely to pose a significant risk to nature shall be preceded by an
exhaustive examination; their proponents shall demonstrate that expected benefits outweigh
potential damage to nature, and where potential adverse effects are not fully understood, the
activities should not proceed;
· Activities which may disturb nature shall be preceded by assessment of their consequences,
and environmental impact studies of development projects shall be constructed in advance,
and if they are to be undertaken, such activities shall be planned and carried out so as to
minimize potential adverse impacts.
These guiding principles have been reaffirmed in a succession of formal intergovernmental
Agreements
243] International Conference on Water and Environment (Dublin) (1992)
Five hundred participants endorsed four guiding principles in the Dublin Statement:
1) Fresh water is a finite and vulnerable resource, essential to sustain life, development and the
environment.
2) Water development and management should be participatory, involving planners and policy
makers at all levels.
3) Women play a central role in the provision, management and safeguarding of water.
4) Water has an economic value in all its competing uses and should be recognised as an
economic good.
Since water sustains life, effective management of water resources demands a holistic
approach, linking social and economic development with protection of natural ecosystems.
Effective management links land and water uses across the whole of a catchment area or
groundwater aquifer
244] The Human Right to Water
Peter Gleick,
President, Pacific Institute for Studies in
Development, Environment, and Security
PACIFIC INSTITUTE FOR STUDIES IN DEVELOPMENT,
ENVIRONMENT, AND SECURITY
654 13th St.
Oakland, CA 94612 USA
510.251.1600 (ph.)
510.251.2203 (fax)
pistaff@pacinst.org
www.pacinst.org
Published in 1(More than a billion people in the developing world lack safe drinking water – an amenity those in the developed
world take for granted. Nearly three billion people live without access to adequate sanitation systems necessary
for reducing exposure to water-related diseases. The failure of the international aid community, nations, and local
organizations to satisfy these basic human needs has led to substantial, unnecessary, and preventable human
suffering. This paper argues that access to a basic water requirement is a fundamental human right implicitly and
explicitly supported by international law, declarations, and State practice. Governments, international aid agencies,
non-governmental organizations, and local communities should work to provide all humans with a basic
water requirement and to guarantee that water as a human right. By acknowledging a human right to water and
expressing the willingness to meet this right for those currently deprived of it, the water community would have a
useful tool for addressing one of the most fundamental failures of 20th century development.
245] The Water Cycle
Water is continually moving around, through, and above the Earth as water vapor, liquid water, and ice. In fact, water is continually changing its form. The Earth is pretty much a "closed system," like a terrarium. That means that the Earth neither, as a whole, gains nor loses much matter, including water. Although some matter, such as meteors from outer space, are captured by Earth, very little of Earth's substances escape into outer space. This is certainly true about water. This means that the same water that existed on Earth millions of years ago is still here. Thanks to the water cycle the same water is continually being recycled all around the globe.
The Water Cycle (or hydrological cycle) is the continuous transfer of water between the sea, the land and the atmosphere. It is a continuous cycle with no beginning or end.
A basic description of the Water Cycle:
Precipitation (rain, snow, sleet or hail) falls to the ground. This is either:
INTERCEPTED by vegetation or buildings
INFILTRATES into the ground
RUNS-OFF the surface of the ground (as a river or stream).
Energy from the sun evaporates the water. If the air cools it causes condensation (clouds), then precipitation.
River Basins
A river basin is an area of land drained by a river and its tributaries. River basins have typical features, these include:
Tributaries - smaller rivers flowing into a larger river.
A Watershed - an area of highland surrounding the river basin.
A confluence - where a river joins another river.
Source - The start of a river.
Mouth - Where a river meets the sea or an ocean.
Changes from source to mouth
A river flows from an upland source. Here the velocity of water is faster than downstream because the river's gradient is steep. Near a river's source the valley has a narrow floor and steep sides (v- shaped) This is evident in the photograph above).
The middle course of the river has a wider floor and the sides of the valley are more gently sloping. The velocity is slower than the upper stage. However, the channel is wider as the amount of water flowing in it increases as other streams and rivers join it.
The lower course of the river is very gentle sloping, almost flat. The channel is usually at its widest and deepest here because the amount of water flowing within the river is at its greatest.
Erosion
Rivers erode in four ways:
Abrasion or corrasion - This is when large pieces of bedload material wear away the river banks and bed.
Attrition - This is when the bed load itself is eroded when sediment particles knock against the bed or each other and break, becoming more rounded and smaller.
Hydraulic Action - This is when the force of water erodes softer rock.
Solution or corrosion - This is when acidic water erodes rock Flooding
Floods can bring both advantages and disadvantages to an area. Floods can deposit rich, fertile alluvium on agricultural areas. Also, flood water can replenish irrigation channels. On the other hand floods can destroy food supplies, homes and transport infrastructures.
Causes of flooding
Human causes:
Deforestation - Cutting down trees causes increased run-off (water flowing over the surface of the earth). Rain water reaches rivers faster. Flooding becomes more likely.
Urbanisation - Man-made surfaces such as concrete result in greater run-off. Rain water reaches rivers faster and can cause flooding.
Natural causes:
Heavy rainfall
Melting snow
Solutions to flooding
Afforestation - Planting more trees reduces run-off and increases interception.
Dams - Although very expensive, dams can significantly reduce the risk of flooding downstream
Case Study - Ganges/Brahmaputra River Basin
Flooding is a significant problem in the Ganges/Brahmaputra river basin. They cause large scale problems in the low lying country of Bangladesh. There are both human and natural causes of flooding in this area.
Human Causes
Deforestation - Population increase in Nepal means there is a greater demand for food, fuel and building materials. As a result deforestation has increased significantly. This reduces interception and increases run-off. This leads to soil erosion. River channels fill with soil, the capacity of the River Ganges and Brahmaputra is reduced and flooding occurs.
Natural Causes
Monsoon Rain
Melting Snow
Tectonic Activity - The Indian Plate is moving towards the Eurasian Plate. The land where they meet (Himalayas) is getting higher and steeper every year (fold mountains). As a result soil is becoming loose and is susceptible to erosion. This causes more soil and silt in rivers. This leads to flooding in Bangladesh.
246] world’s water system
247] Major ions in sea water
The two ions that are present most often in seawater are are chloride and sodium. These two make up over 90% of all dissolved ions in seawater. By the way, the concentration of salt in seawater (salinity) is about 35 parts per thousand. In other words, about 35 of 1,000 (3.5%) of the weight of seawater comes from the dissolved salts.
248] Water quality measuring units
pH is a measure of how acidic/basic water is. The range goes from 0 - 14, with 7 being neutral. pHs of less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base. pH is really a measure of the relative amount of free hydrogen and hydroxyl ions in the water. Water that has more free hydrogen ions is acidic, whereas water that has more free hydroxyl ions is basic. Since pH can be affected by chemicals in the water, pH is an important indicator of water that is changing chemically. pH is reported in "logarithmic units," like the Richter scale, which measures earthquakes. Each number represents a 10-fold change in the acidity/basicness of the water. Water with a pH of 5 is ten times more acidic than water having a pH of six.
249] Specific conductance
Specific conductance is a measure of the ability of water to conduct an electrical current. It is highly dependent on the amount of dissolved solids (such as salt) in the water. Pure water, such as distilled water, will have a very low specific conductance, and sea water will have a high specific conductance. Rainwater often dissolves airborne gasses and airborne dust while it is in the air, and thus often has a higher specific conductance than distilled water. Specific conductance is an important water-quality measurement because it gives a good idea of the amount of dissolved material in the water.
Probably in school you've done the experiment where you hook up a battery to a light bulb and run two wires from the battery into a beaker of water. When the wires are put into a beaker of distilled water, the light will not light. But, the bulb does light up when the beaker contains salt water (saline). In the saline water, the salt has dissolved, releasing free electrons, and the water will conduct an electrical current.
250] What determines hardness of water?
Hardness
The amount of dissolved calcium and magnesium in water determines its "hardness."
250] Water Basics
Water is generally classified into two groups: Surface Water and Ground Water. Surface water is just what the name implies; it is water found in a river, lake or other surface impoundment. This water is usually not very high in mineral content, and many times is called "soft water" even though it usually is not. Surface water is exposed to many different contaminants, such as animal wastes, pesticides, insecticides, industrial wastes, algae and many other organic materials. Even surface water found in a pristine mountain stream possibly contains Giardia or Coliform Bacteria from the feces of wild animals, and should be boiled or disinfected by some means prior to drinking
Ground Water is that which is trapped beneath the ground. Rain that soaks into the ground, rivers that disappear beneath the earth, melting snow are but a few of the sources that recharge the supply of underground water. Because of the many sources of recharge, ground water may contain any or all of the contaminants found in surface water as well as the dissolved minerals it picks up during it's long stay underground. Waters that contains dissolved minerals, such as calcium and magnesium above certain levels are considered "hard water" Because water is considered a "solvent", i.e., over time it can break down the ionic bonds that hold most substances together, it tends to dissolve and 'gather up' small amounts of whatever it comes in contact with. For instance, in areas of the world where rock such as limestone, gypsum, fluorspar, magnetite, pyrite and magnesite are common, well water is usually very high in calcium content, and therefore considered "hard".
Due to the different characteristics of these two types of water, it is important that you know the source of your water -- Surface or Ground. Of the 326 million cubic miles of water on earth, only about 3% of it is fresh water; and 3/4 of that is frozen. Only 1/2 of 1% of all water is underground; about 1/50th of 1% of all water is found in lakes and streams. The average human is about 70% water. You can only survive 5 or less days without water
251] What determines hardness of water?
Hardness
The amount of dissolved calcium and magnesium in water determines its "hardness."
252] What are hardness minerals?
Calcium, manganese and magnesium are the most common
253] Why Should Hard Water Concern Me?
For many uses, it would not matter. For instance, to put out fires, water your lawn, wash the mud off the streets or float your boat, water would have to be pretty hard to cause a problem. But for bathing, washing dishes and clothes, shaving, washing your car and many other uses of water, hard water is not as efficient or convenient as "soft water." For instance:
· you use only 1/2 as much soap cleaning with soft water.
· because hard water and soap combine to form "soap scum" that can't be rinsed off, forming a 'bathtub ring' on all surfaces and drys leaving unsightly spots on your dishes.
· when hard water is heated, the hardness minerals are re-crystallized to form hardness scale. This scale can plug your pipes and hot water heater, causing premature failure, and costly replacement.
· the soap scum remains on your skin even after rinsing, clogging the pores of your skin and coating every hair on your body. This crud can serve as a home for bacteria, causing diaper rash, minor skin irritation and skin that continually itches.
· for many industrial uses, the hardness minerals interfere with the process, causing inferior product.
254] Coliform bacteria are a group of microorganisms that are normally found in the intestinal tract of humans and other warm blooded animals, and in surface water. The presence of these organisms in drinking water suggest contamination from a surface or shallow subsurface source such as cesspool leakage, barnyard runoff or other source. The presence of these bacteria indicate that disease-causing (pathogenic) organisms may enter the drinking water supply in the same manner if preventive action is not taken.
255] Nitrate in drinking water supplies may reduce the oxygen carrying capacity of the blood (cyanosis) if ingested in sufficient amounts by infants under 6 months of age. This could cause a disease called "methemoglobinemia", or "blue baby" syndrome. Unlike Coliform or other types of bacteria, boiling the water will actually INCREASE the amount of nitrate remaining in the water, increasing the danger to infants. If you have high nitrate water, either treat it with an approved treatment methodology or find another source: Boiling will only make it worse!
256] Cysts and viruses are microbiological contaminants, usually found in surface water supplies. Giardia lamblia cysts can cause giardiasis, a gastrointestinal disease. Another "bug" getting a lot of attention lately, is cryptosporidium, single-cell parasite measuring about 2 - 5 microns in diameter. Many surface water supplies contain this pest, which also comes from the intestine of warm blooded animals.
257] Land subsidence
Land subsidence occurs when large amounts of ground water have been withdrawn from certain types of rocks, such as fine-grained sediments. The rock compacts because the water is partly responsible for holding the ground up. When the water is withdrawn, the rocks falls in on itself. You may not notice land subsidence too much because it can occur over large areas rather than in a small spot, like a sinkhole. That doesn't mean that subsidence is not a big event –
Sinkholes are common where the rock below the land surface is limestone, carbonate rock, salt beds, or rocks that can naturally be dissolved by ground water circulating through them. As the rock dissolves, spaces and cavernsdevelop underground. Sinkholes are dramatic because the land usually stays intact for a while until the underground spaces just get too big. If there is not enough support for the land above the spaces then a sudden collapse of the land surface can occur
258] Just how much water is there on (and in) the Earth? Here are some numbers you can think about:
The total water supply of the world is 326 million cubic miles (a cubic mile is an imaginary cube (a square box) measuring one mile on each side). A cubic mile of water equals more than one trillion gallons.
About 3,100 cubic miles of water, mostly in the form of water vapor, is in the atmosphere at any one time. If it all fell as precipitation at once, the Earth would be covered with only about 1 inch of water.
Each day, 280 cubic miles of water evaporate or transpire into the atmosphere
Of the freshwater on Earth, much more is stored in the ground than is available in lakes and rivers. More than 2,000,000 cubic miles of fresh water is stored in the Earth, most within one-half mile of the surface. Contrast that with the 60,000 cubic miles of water stored as fresh water in lakes, inland seas, and rivers. But, if you really want to find fresh water, the most is stored in the 7,000,000 cubic miles of water found in glaciers and icecaps, mainly in the polar regions and in Greenland.
Information on this page is from "The Hydrologic Cycle (Pamphlet), U.S. Geological Survey, 1984
259]
Water source Water volume, incubic miles Percent oftotal water
Oceans 317,000,000 97.24%
Icecaps, Glaciers 7,000,000 2.14%
Ground water 2,000,000 0.61%
Fresh-water lakes 30,000 0.009%
Inland seas 25,000 0.008%
Soil moisture 16,000 0.005%
Atmosphere 3,100 0.001%
Rivers 300 0.0001%
Total water volume 326,000,000 100%
Source: Nace, U.S. Geological Survey, 1967
260] Distributed Aquifer Recharge Enhancements in Arid Zones
Enrique R. Vivoni
Ralph M. Parsons Laboratory
Massachusetts Institute of Technology
Abstract
Enhanced aquifer recharge is one alternative to the water sustainability crisis occurring in many arid regions. Intermittent and intense rainfall events over an arid watershed can lead to short term surface water availability. Without the proper management of this water resource, the excess precipitation can be quickly lost to the high evaporative environment or lost from the watershed via runoff. By ensuring that the available surface water remains within the catchment in the form of stored groundwater, a sustainable flux of water is obtained for the region (Eltahir, 1996). Sustainability, defined in this perspective, allows a water resources manager to focus on ensuring a consistent yield corresponding to the climatically variable input.
Conclusions
Currently, the use of artificial recharge to an aquifer is seen as a potential solution to the sustainable water supply needs of various arid and semiarid regions. One needs only to inspect the rising number of projects being designed and constructed in the semiarid southwest of the United States to appreciate the growing popularity of engineered recharge systems (ENR, 1999a,b; WATER/Engineering and Management, 1995, 1999). Other types of aquifer recharge and water harvesting systems have been implemented in many arid region over the past hundreds of years. Despite this wealth of engineering knowledge, a quantitative hydrological analysis of an artificial recharge system that considers the impact of the competing hydrological processes in arid regions has not been performed. This preliminary study takes a small step in that direction by presenting the conceptual design and initial modeling results of the Branched Aquifer Recharge System (BARS).
The Branched Aquifer Recharge System takes advantage of the hydrologic processes that favor the increase of vertical transport of water through the unsaturated zone, the concentration of flow by topographical constraints and the reduction of evaporative loss due to the high atmospheric evaporative demand. Four basic elements comprise the hydrologic engineering technology: hillslope collectors, a branched network of underground tunnels for storage and distribution, convergence zone collectors with an overflow structure to a transmission line and supply well.
261]
Periods of water resources renewal on the Earth
Water of Hydrosphere Period of renewal
World Ocean 2500 years
Ground water 1400 years
Polar ice 9700 years
Mountain glaciers 1600 years
Ground ice of the permafrost zone 10000 years
Lakes 17 years
Bogs 5 years
Soil moisture 1 years
Channel network 16 days
Atmospheric moisture 8 days
Biological water several hours
262] General Water Saving Tips
Be aware of and follow all water conservation and water shortage rules in effect in your community. Don’t assume — even if you get your water from a private well — that you need not observe good water use rules. Every drop counts.
Encourage your employer to promote water conservation in the workplace. Suggest that water conservation be put in employee orientation and training programs.
Report all significant water losses (broken pipes, open hydrants, errant sprinklers, abandoned free-flowing wells, etc.) to the property owner, local authorities or your water management district.
Encourage your school system and local government to help develop and promote a water conservation ethic among children and adults.
Support projects that will lead to an increased use of reclaimed waste water for irrigation and other uses.
Support efforts and programs that create a concern for water conservation among tourists and visitors to our state. Make sure your visitors understand the need for, and benefits of, water conservation.
Encourage your friends and neighbors to be part of a water-conscious community. Promote water conservation in community newsletters, on bulletin boards and by example. Encourage your friends, neighbors and co-workers to “do their part”.
Conserve water because it is the right thing to do. Don’t waste water just because someone else is footing the bill, such as when you are staying at a hotel.
Try to do one thing each day that will result in saving water. Don’t worry if the savings are minimal. Every drop counts. You can make a difference.
263] Saving Water Indoors
1 Never pour water down the drain when there may be another use for it such as watering a plant or garden, or for cleaning.
2 Verify that your home is leak free. Many homes have hidden water leaks. Read your water meter before and after a two-hour period when no water is being used. If the meter does not read exactly the same, there is a leak.
3 Repair dripping faucets by replacing washers. If your faucet is dripping at a rate of one drop per second, you can expect to waste 2,700 gallons per year. This adds to the cost of water and sewer utilities, or can strain your septic system.
4 Retrofit all household faucets by installing aerators with flow restrictors.
5 Check for toilet tank leaks by adding food coloring to the tank. If the toilet is leaking, color will appear in the toilet bowl within 30 minutes. Check the toilet for worn out, corroded or bent parts. Most replacement parts are inexpensive, readily available and easily installed. (Flush as soon as test is done, since food coloring may stain tank.)
6 If the toilet handle frequently sticks in the flush position letting water run constantly, replace or adjust it.
7 Install a toilet dam or displacement device such as a bag or bottle to cut down on the amount of water needed for each flush. Be sure installation does not interfere with the operating parts. When purchasing new or replacement toilets, consider low-volume units which use less than half the water of older models. In many areas, low-volume units are required by law.
8 Take shorter showers. Replace your showerhead with an ultra-low-flow version. Some units are available that allow you to cut off the flow without adjusting the water temperature knobs.
9 Place a bucket in the shower to catch excess water and use this to water plants. The same technique can be used when washing dishes or vegetables in the sink.
10 In the shower, turn water on to get wet; turn off to lather up; then turn back on to rinse off. Repeat when washing your hair.
11 Operate automatic dishwashers and clothes washers only when they are fully loaded. Set the water level for the size of load you are using.
12 When washing dishes by hand, fill one sink or basin with soapy water. Quickly rinse under a slow-moving stream from the faucet.
13 Store drinking water in the refrigerator. Don't let the tap run while you are waiting for cool water to flow.
14 Do not use running water to thaw meat or other frozen foods. Defrost food overnight in the refrigerator or use the defrost setting on your microwave.
15 Kitchen sink disposals require lots of water to operate properly. Start a compost pile as an alternate method of disposing of food waste, instead of using a garbage disposal. Garbage disposals also can add 50 percent to the volume of solids in a septic tank, which can lead to malfunctions and maintenance problems.
16 Consider installing an instant water heater on your kitchen sink so you don't have to let the water run while it heats up. This will reduce water heating costs for your household.
17 Insulate your water pipes. You'll get hot water faster and avoid wasting water while it heats up.
18 Never install a water-to-air heat pump or air-conditioning system. Newer air-to-air models are just as efficient and do not waste water.
19 Don't let water run while shaving or washing your face. Brush your teeth first while waiting for water to get hot, then wash or shave after filling the basin.
20 Install water softening systems only when necessary. Save water and salt by running the minimum amount of regenerations necessary to maintain water softness. Turn softeners off while on vacation.
21 If you have a well at home, check your pump periodically. Listen to hear if the pump kicks on and off while water is not being used. If it does, you have a leak.
22 Avoid flushing the toilet unnecessarily. Dispose of tissues, insects and other similar waste in the trash rather than the toilet.
Saving Water Outdoors
23 Don't overwater your lawn. As a general rule, lawns only need watering every five to seven days in the summer and every 10 to 14 days in the winter. A hearty rain eliminates the need for watering for up to two weeks. Buy a rain gauge and use it to determine how much rain your yard has received. Most of the year, lawns only need one inch of water per week.
24 Plant it smart. Xeriscape landscaping is a great way to design, install and maintain both your plants and irrigation system. More importantly, it will save time, money and water. For your free copy of Plant It Smart, an easy-to-use guide to Xeriscape landscaping, contact your water management district.
25 Water lawns during the early morning hours when temperatures and wind speed are the lowest. This reduces losses from evaporation.
26 Don't allow sprinklers to water your street, driveway or sidewalk. Position them so water lands on the lawn and shrubs... not the paved areas.
27 Install irrigation devices that are the most water efficient for each use. Micro and drip irrigation and soaker hoses are examples of water efficient irrigation methods.
28 Check sprinkler systems and timing devices regularly to be sure they operate properly. Florida law now requires that "anyone who purchases and installs an automatic lawn sprinkler system MUST install a rain sensor device or switch which will override the irrigation cycle of the system when adequate rainfall has occurred." To retrofit your existing system, contact an irrigation professional for more information.
29 Raise the lawn mower blade to at least three inches or to its highest level. A higher cut encourages grass roots to grow deeper, shades the root system and holds soil moisture better than a closely-clipped lawn.
30 Avoid over fertilizing your lawn. Fertilizer applications increase the need for water. Apply fertilizers which contain slow-release, water-insoluble forms of nitrogen.
31 Use mulch to retain moisture in the soil. Mulch also helps control weeds that compete with landscape plants for water.
32 Plant native and/or drought-tolerant grasses, ground covers, shrubs and trees. Once established, they do not need water as frequently and usually will survive a dry period without watering. Group plants together based on similar water needs.
33 Do not hose down your driveway or sidewalk. Use a broom to clean leaves and other debris from these areas.
34 Use a shut-off nozzle on your hose which can be adjusted down to a fine spray so that water flows only as needed. When finished, turn it off at the faucet instead of at the nozzle to avoid leaks. Check hose connectors to make sure plastic or rubber washers are in place. Washers prevent leaks.
35 Do not leave sprinklers or hoses unattended. A garden hose can pour out 600 gallons or more in only a few hours. Use a kitchen timer to remind yourself to turn sprinklers off.
36 Avoid purchasing recreational water toys which require a constant stream of water.
37 Consider using a commercial car wash that recycles water. If you wash your own car, park on the grass and use a hose with an automatic shut-off nozzle.
38 Avoid the installation of ornamental water features (such as fountains) unless the water is recycled.
39 If you have a swimming pool, consider a new water-saving pool filter. A single backflushing with a traditional filter uses 180 to 250 gallons of water.
General Water Saving Tips
40 Get involved in water management issues. Voice your questions and concerns at public meetings conducted by your local government or water management district.
41 Be aware of and follow all water conservation and water shortage rules in effect in your community. Don't assume -- even if you get your water from a private well -- that you need not observe good water use rules. Every drop counts.
42 Encourage your employer to promote water conservation in the workplace. Suggest that water conservation be put in employee orientation and training programs.
43 Patronize businesses which practice and promote water conservation, such as restaurants that only serve water upon request.
44 Report all significant water losses (broken pipes, open hydrants, errant sprinklers, abandoned free-flowing wells, etc.) to the property owner, local authorities or your water management district.
45 Encourage your school system and local government to help develop and promote a water conservation ethic among children and adults.
46 Support projects that will lead to an increased use of reclaimed waste water for irrigation and other uses.
47 Support efforts and programs that create a concern for water conservation among tourists and visitors to our state. Make sure your visitors understand the need for, and benefits of, water conservation.
48 Encourage your friends and neighbors to be part of a water-conscious community. Promote water conservation in community newsletters, on bulletin boards and by example. Encourage your friends, neighbors and co-workers to "do their part."
49 Conserve water because it is the right thing to do. Don't waste water just because someone else is footing the bill, such as when you are staying at a hotel.
50 Try to do one thing each day that will result in saving water. Don't worry if the savings are minimal. Every drop counts. You can make a difference
264] Water saving tips outdoors
· Water your lawn during the late evening hours when the temperatures are low and the amount of evaporation is reduced.
· After washing your car, rinse off the suds with a bucket of clean water. Don't waste water using a hose.
265] water savings methods you can practise
· When it rains, collect rainwater in a bucket. You can play in this water instead of
using the hose.
· To clean your stuffed animals, take them in the tub with you when you take a bath.
When you get a drink of water, only fill your glass halfway. Then you won't have
to throw out the water you don't drink. If you still don't drink it all, pour it in house-
plants instead of down the drain
· Use a bucket and sponge to wash your bicycle instead of letting the hose run.
· At the water fountain, use a paper cup instead of trying to gulp down all that water
at one time. After you are done, recycle the cup.
· By turning the water off while you brush your teeth, you can save 2 - 3 gallons of
water a dayWhen your parents boil foods such as noodles or potatoes, have them save the water. After it cools, it can be used to water houseplants.
· Use a broom to clean sidewalks instead of using a hose. It's not as much fun, but
it saves water.
· If the water is too hot, turn down the hot instead of turning up the cold.
· Don't water the lawn when it's going to rain.
Make sure you don't have any leaky faucets
266] water quotations and proverbs
A fool and water will go the way they are diverted.
Ethiopian Proverb
A fool is thirsty in the midst of water.
Ethiopian Proverb
Beware of silent dogs and still waters.
Portuguese Proverb
Children's love is like water in a basket.
Argentine Proverb (1904 - 1991) English novelist
Don't throw away the old bucket until you know whether the new one holds water.
Swedish Proverb
Gardening requires lots of water -- most of it in the form of perspiration.
Lou Erickson (1859 - 1930) Scottish author, physician
In the "Atlanta Journal and Constitution."
I believe that any man's life will be filled with constant and unexpected encouragement, if he makes up his mind to do his level best each day, and as nearly as possible reaching the high water mark of pure and useful living.
Booker T. Washington (1856 - 1915) US educator, social reformer
In The Ultimate Success Quotations Library, 1997
In the world there is nothing more submissive and weak than water. Yet for attacking that which is hard and strong nothing can surpass it.
Lao-Tzu (c. 570BC - ????) Chinese philosopher
"Tao-te-ching," bk. 2, ch. 78.
My father had always said there are four things a child needs: plenty of love, nourishing food, regular sleep, and lots of soap and water. After that, what he needs most is some intelligent neglect.
Ivy Baker Priest (1905 - 1975) US government official
"Green Grows Ivy," Ch. 11, 1958.
OCEAN, n. A body of water occupying about two-thirds of a world made for man -- who has no gills.
Ambrose Bierce (1842 - 1914) US journalist, short-story writer
The Devil's Dictionary, 1911
One kernel is felt in a hogshead; one drop of water helps to swell the ocean; a spark of fire help to give light to the world. None are too small, too feeble, too poor to be of service. Think of this and act.
Hannah More (1745 - 1833) English writer
In "Poor Man's College Quotations Collection," ed. Sidney Madwed, AAPEX software, 1994.
POTABLE, n. Suitable for drinking. Water is said to be potable; indeed, some declare it our natural beverage, although even they find it palatable only when suffering from the recurrent disorder known as thirst, for which it is a medicine.
Ambrose Bierce (1842 - 1914) US journalist, short-story writer
The Devil's Dictionary, 1911.
Water is the only drink for a wise man.
Henry David Thoreau (1817 - 1862) US essayist, poet, naturalist
In The Ultimate Success Quotations Library, 1997
When you drink the water, remember the spring.
Chinese Proverb
You can't trust water: Even a straight stick turns crooked in it.
W. C. Fields (1880 - 1946) US actor, comedian
In The Ultimate Success Quotations Library, 1997.
You can't trust water: Even a straight stick turns crooked in it.
W. C. Fields (1880 - 1946) US actor, comedian
In The Ultimate Success Quotations Library, 1997.
You cannot turn blood into water.
Albanian Proverb from Albania
Stolen waters are sweet, and bread eaten in secret is pleasant. Proverbs 9:17
BiblicalProverb from Biblical*
Enough shovels of earth -- a mountain. Enough pails of water -- a river.
Chinese Proverb from China
Far waters cannot quench near fires.
Chinese Proverb from China
= Found in: NA.htm
Flowing water never gets dirty.
Chinese Proverb from China
One monk shoulders water by himself; two can still share the labor among them. When it comes to three, they have to go thirsty.
Chinese Proverb from China
The greatest virtue is like water; good for everything.
Chinese Proverb from China
Water and words are easy to pour but impossible to recover.
Chinese Proverb from China
Water can do without fishes, fishes cannot do without water.
Chinese Proverb from China
Well water is not an enemy of spring water.
Chinese Proverb from ChinaWell water is not an enemy of spring water.
Chinese Proverb from China
When someone gives you a drop of water reward him with a never ending source.
Chinese Proverb from China
When you drink water, remember where the mountain spring is.
Chinese Proverb from China
Extol the virtue of water, but drink wine.
Czech Proverb from Czech Republic
Don't throw away dirty water before you have more clean water.
Danish Proverb from Denmark
There is no worse water than still water.
French Proverb from France
= Found in: NA.htm
We never know the worth of water till the well is dry.
French Proverb from France
You do not fatten pigs with pure water.
French Proverb from France
A visit is like rainwater; you pray for it when it stays away and its a problem when it rains too much.
Hebrew Proverb from Hebrew
The water of the river flows on without waiting for the thirsty man.
Kenyan Proverb from Kenya
Let the water you cannot drink flow by.
Mexican Proverb from Mexico
Even foul water will quench fire.
Mongolian Proverb from Mongolia
Water teaches us to weep, wine teaches us to sing.
Polish Proverb from Poland
The water from the river becomes salty when it reaches the ocean.
Sanskrit Proverb from Sanskrit*
= Found in: NA.htm
* denotes a proverb from a 'culture' (or ethnic group) within a country or that spans several countries.
There are three things that refresh the heart and reduce your grief water, flowers, and a beautiful woman.
Sanskrit Proverb from Sanskrit
We'll never know the worth of water till the well go dry.
Scottish Proverb from Scottish*
When there is a war between fire and water, fire loses.
Spanish Proverb from Spain
The word "enough" does not exist for water, fire, and women.
Ukranian Proverb from Ukraine
Two burdens: to Moses water, to God the world.
Yiddish Proverb from Yiddish
The horse that arrives early gets good drinking water.
Zulu Proverb from Zulu
267] WATER CONSERVATION IDEAS FOR BEVERAGE INDUSTRIES
Mark Schweiker, Governor Commonwealth of Pennsylvania
David Hess, Secretary Department of Environmental Protection
GENERAL SUGGESTIONS
Appoint a water conservation coordinator with the responsibility and authority for the water conservation program.
Make the plant manager and other employees aware of the water conservation coordinator's function.
Increase employee awareness of water conservation:
*Explain the importance of individual actions to the success of the program. *Seek employee ideas for water conservation using contests, rewards, and suggestion boxes.
Read water meter daily to monitor and report the success of water conservation efforts.
SURVEY THE PLANT
A plant survey helps to establish facility water savings potential by identifying areas where water is wasted or where water could be reused.
Identify the major water lines. Determine the quality, quantity, and temperature of water carried by each.
Identify all points where water is used, including hose connections. Determine the quantity of water used at each point.
Determine the capacity of each water-containing unit and frequency of emptying.
Determine the capacity of each continuous discharge not yet being reused.
Determine flow rates in floor gutters and whether the flows are adequate to prevent solids accumulation.
EVALUATE SURVEY
Review the information developed during the survey:
*Identify the major water-using operations*Review the water re-use practices currently employed.
Develop plans to improve re-use:
*Evaluate the feasibility of installing cooling towers. *Study the potential for screening and disinfecting reclaimed water to increase the number of times it can be re-used.
EFFICIENCY
Install high-pressure low-volume nozzles on spray washers.
Use fogging nozzles to cool product.
Install in-line strainers on all spray headers; inspect nozzles regulatory for clogging.
Adjust pump cooling and flushing water to theDetermine whether discharges from any operation can be substituted for fresh water supplied to another operation.
Discharges that can potentially be re-used are:
*Final rinses from tank cleaning, keg washers, fermenters; *Bottle and can soak and rinse water; *Cooler flush water, filter backwash; and *Pasteurizer and sterilizer water.
Areas of possible re-use are:
*First rinses in wash cycles: *Can shredder, bottle crusher; *Filter backflush; *Caustic dilution; *Boiler makeup; *Refrigeration equipment defrost; and *Equipment cleaning, floor and gutter wash.
Use conveying systems that use water efficiently Handle waste materials in a dry mode if possible.
Replace high-volume hoses with high-pressure, low-volume cleaning systems.
As equipment wears out, replace with water-saving models.
Equip all hoses with spring loaded shutoff nozzles. Be sure these nozzles are not removed.
Instruct employees to use hoses sparingly and only when necessary.
Adjust overflows from recirculation systems by controlling the rate at which make-up water is added:
*Install float-controlled valve on the makeup line. *Close filling line during operation. *Provide surge tanks for each system to avoid overflow.
Turn off all flows during shutdowns (unless flows are essential for cleanup). Use solenoid valves to stop the flow of water when production stops. The valves could be activated by tying them to drive motor controls.
Adjust flow in sprays and other lines to meet minimum requirements.
EVALUATE CLEAN-UP PROCEDURES
Sweep and shovel solid materials from the floor; do not use hoses for this purpose:
Provide an adequate number of receptacles for collecting solids. *Empty the receptacles frequently to prevent odor and insect problems.
Inventory all cleaning equipment (such as hoses) provided in the plant:
*Determine the number and types of units provided. *Evaluate their frequency of operation. *Use more water-efficient equipment where possible.
Inventory all cleaning chemicals used in the facility to determine: *If they are being used correctly. *Their water use efficiency.
EXTERIOR AREAS
Wash autos, buses, and trucks less often.
Discontinue using water to clean sidewalks, driveways, loading docks, and parking lots. Consider using mobile sweepers and vacuums.
Avoid landscape fertilizing and pruning stimulating excessive growth.
Remove weeds and unhealthy plants so remaining plants can benefit from the water saved.
In many cases, older, established plants require only infrequent irrigation. Look for indications of water need, such as wilting, change of color, or dry soils.
Limit landscaping additions and alterations.
In the future, design landscapes requiring less water.
Install soil moisture overrides or timers on sprinkler systems.
Time watering, when possible, to occur in the early morning or evening when evaporation is lowest.
Make sure irrigation equipment applies water* uniformly.
Investigate the advantages of installing drip irrigation systems.
Mulch around plants to reduce evaporation and discourage weeds.
Remove thatch and aerate turf to encourage the movement of water to the root zone.
Avoid runoff and make sure sprinklers cover just the lawn or garden, not sidewalks, driveways, or gutters.
Do not water on windy days.
For more information contact:
Division of Water Use Planning
P.O. Box 8555
Harrisburg, PA 17105-8555
Telephone: 717-772-4048
FAX: 717-787-9549
E-Mail: Drought.Info@dep.state.pa.us
An Equal Opportunity/Affirmative Action Employer
268] WATER CONSERVATION IDEAS FOR COMMERCIAL BUILDINGS
Mark Schweiker, Governor Commonwealth of Pennsylvania
David Hess, Secretary Department of Environmental Protection
GENERAL SUGGESTIONS
Increase employee awareness of water conservation.
Install signs encouraging water conservation in employee and customer restrooms.
When cleaning with water is necessary, use budgeted amounts.
Determine the quantity and purpose of water being used.
Read water meter weekly to monitor success of water conservation efforts.
Assign an employee to monitor water use and waste.
Seek employee suggestions on water conservation; locate suggestion boxes in prominent areas.
Determine other methods of water conservation.
BUILDING MAINTENANCE
Check water supply system for leaks.
Turn off any unnecessary flows.
Repair dripping faucets, showers and continuously running or leaking toilets.
Install faucet aerators where possible.
Reduce the load on air conditioning units by shutting off air conditioning when and where it is not needed.
Reduce toilet water by adjusting flush valves or installing dams and flapper mechanisms.
As appliances or fixtures wear out, replace them with water-saving models.
Shut off water supply to equipment rooms not in use.
Minimize the water used in cooling equipment in accordance with manufacturers recommendations. Shut off cooling units when not needed.
CAFETERIA AREA
Turn off the continuous flow used to clean the drain trays.
Turn dishwasher off when not in use. Wash full loads only.
Use water from steam tables to wash down cooking area.
Do not use running water to melt ice or frozen foods.
Use water-conserving ice makers.
EXTERIOR AREAS
Inventory outdoor water use for landscaped areas.
Water landscapes only when needed. Two-to-three times a week is usually sufficient.
Water in the early morning or evening.
Make sure that water does not run into the streets or alleys.
Stop hosing down sidewalks, driveways, and parking lots.
Use time controllers on sprinkler systems.
Do not water on windy days
269] WATER CONSERVATION IDEAS FOR FOOD PROCESSING FACILITIES
Mark Schweiker, Governor Commonwealth of Pennsylvania
David Hess, Secretary Department of Environmental Protection
GENERAL SUGGESTIONS
Appoint a water conservation coordinator with the responsibility and authority for the water conservation program.
Make the plant manager and other employees aware of the water conservation coordinator's function.
Increase employee awareness of water conservation:
* Explain the importance of individual actions to the success of the program. * Seek employee ideas for water conservation using contests, rewards, and suggestion boxes.
Read water meter daily to monitor and report the success of water conservation efforts.
SURVEY THE PLANT
A plant survey helps to establish facility water savings potential by identifying areas where water is wasted or where water could be reused.
Identify the major water lines. Determine the quality, quantity, and temperature of water carried by each.
Identify all points where water is used, including hose connections. Determine the quantity of water used at each point.
Determine the capacity of each water-containing unit and frequency of emptying.
Determine the capacity of each continuous discharge not yet being reused.
Determine flow rates in floor gutters and whether the flows are adequate to prevent solids accumulation.
EVALUATE SURVEY
Review the information developed during the survey to identify the major water-using operations and review the water re-use practices currently employed.
Develop plans to improve re-use:
* Evaluate the feasibility of installing cooling towers. * Study the potential for screening and disinfecting reclaimed water to increase the number of times it can be re-used.
MAXIMUM WATER-USE EFFICIENCY
Install high-pressure low-volume nozzles on spray washers.
Use fogging nozzles to cool product.
Install in-line strainers on all spray headers; inspect nozzles regularly for clogging.
Adjust pump cooling and flushing water to the minimum required.
Use conveying systems that use water efficiently.
*Handle waste materials in a dry state when possible. *Use conveyor belts for product transport; preference should be given to "rabbit-ear" or "V" shaped roller supports because these are much easier to clean. *Use pneumatic conveying systems wherever possible. *Use flumes with parabolic cross sections rather than flat- bottom troughs.
Establish optimum depth of product on conveyors to maximize wash water efficiency.
Replace water-intensive units with alternatives:
* Rubber-disk units for raw product cleaning and peeling: * Steam for water blanchers; or * Evaporative coolers for hydrocooling systems.
Determine whether discharges from any operation can be substituted for fresh water supplied to another operation.
* Divide the spray wash units into two or more sections and establish a counter flow re-use system. * Use reclaimed water for flushing floor gutters.
Replace high-volume hoses with high pressure, low-volume cleaning systems.
As equipment wears out, replace with water-saving models.
AVOID WASTE
Equip all hoses with spring loaded shutoff nozzles. Be sure these nozzles are not removed.
Instruct employees to use hoses sparingly and only when necessary.
Adjust flows from recirculation systems (washers, flumes) by controlling the rate of makeup water:
* Install float-controlled valve on the makeup line. * Close filling line during operation. * Provide surge tanks for each system to avoid overflow.
Turn off all flows during shutdowns (unless flows are essential for clean-up). Use solenoid valves to stop the flow of water when production stops. The valves could be activated by tying them to drive motor controls.
Adjust flows in sprays and other lines to meet the minimum requirements.
EVALUATE CLEAN-UP PROCEDURES
Sweep and shovel solid materials from the floor; do not use hoses for this purpose:
Provide an adequate number of receptacles for collecting solids. * Empty the receptacles frequently to prevent odor and insect problems.
Inventory all cleaning equipment (such as hoses) provided in the plant:
* Determine the number and types of units provided. * Evaluate their frequency of operation; and * Use more water-efficient equipment where possible.
Inventory all cleaning chemicals used in the facility to determine:
* If they are being used correctly. * Their water use efficiency.
Control belt sprays with a timer to allow for the intermittent application for chlorinated water
EXTERIOR AREAS
Discontinue using water to clean sidewalks, driveways, loading docks, and parking lots. Consider using mobile sweepers and vacuums.
Wash autos, buses, and trucks less often.
Avoid plant fertilizing and pruning that would stimulate excessive growth.
Remove weeds and unhealthy plants so remaining plants can benefit from the water saved.
In many cases, older, established plants require only infrequent irrigation. Look for indications of water need, such as wilt, change of color, or dry soils.
Limit landscaping additions and alterations. In the future, design landscapes requiring less water.
Install soil moisture overrides or timers on sprinkler systems.
Time watering, when possible, to occur in the early morning or evening when evaporation is lowest.
Make sure irrigation equipment applies water uniformly.
Mulch around plants to reduce evaporation and discourage weeds.
Remove thatch and aerate turf to encourage the movement of water to the root zone.
Begin a flexible watering schedule, watering only when needed, and not on windy or rainy days.
Avoid runoff and make sure sprinklers cover just the lawn or garden, not sidewalks, driveways, or gutters.
Do not water on windy days
270] WATER CONSERVATION IDEAS FOR HEALTH CARE FACILITIES
Mark Schweiker, Governor Commonwealth of Pennsylvania
David Hess, Secretary Department of Environmental Protection
GENERAL SUGGESTIONS
Increase employee awareness of water conservation.
Seek employee suggestions on water conservation; locate suggestion boxes in prominent areas.
Conduct contests for employees (e.g., posters, slogans, or conservation ideas).
Determine other methods of water conservation.
Install signs encouraging water conservation in employee and customer restrooms.
When cleaning with water is necessary, use budgeted amounts.
Read water meter weekly to monitor success of water conservation efforts.
Assign an employee to monitor water use and waste.
Determine the quantity and purpose of water being used.
Install signs encouraging water conservation in patient and nonpatient rooms and restrooms.
Use paper cups for drinking water instead of free-flowing drinking fountains.
BUILDING MAINTENANCE
Check water supply system for leaks and turn off any unnecessary flows.
Repair dripping faucets, showers and continuously running or leaking toilets.
Reduce the water used in toilet flushing by either adjusting the vacuum flush mechanism or installing toilet tank displacement devices (dams, bottles, or bags).
Install flow reducers and faucet aerators in all plumbing fixtures whenever possible. As fixtures wear out, replace them with water saving models.
Shut off water supply to equipment and rooms not in use.
Discontinue water circulation pumping in unoccupied areas.
Ensure return of steam condensate to the feed water tank for re- use.
Shut off spray coil units, except where humidity in critical areas cannot be maintained by other means or where the units are used to reduce chiller operation.
Keep hot water pipes insulated.
Avoid excessive boiler and air conditioner blow down. Monitor total dissolved solids levels and blow down only when needed.
Minimize the water used in cooling equipment, such as air compressors, in accordance with the manufacturer recommendations.
CAFETERIA AND KITCHEN AREAS
Turn off the continuous flow used to clean the drain trays of the coffee/milk/soda beverage island.
Turn dishwasher off when not in use. Wash full loads only.
Use water from steam tables to wash down cooking area.
Do not use running water to melt ice or frozen foods. If necessary, use ponded water.
Use water-conserving ice makers.
Provide table signs in cafeteria urging water conservation.
Wash vegetables in ponded water; do not let water run in preparation sink.
Recycle rinse water from the dishwater.
LAUNDRY FACILITIES
Reprogram machines to eliminate a rinse or suds cycle, if possible, and not restricted by health regulations.
Reduce water levels, where possible, to minimize water required per load of washing.
Wash full loads only.
Evaluate wash formula and machine cycles for water use efficiency.
OPERATIONS
Turn off water required for film processing or cooling in the X-ray department when not in use.
Recycle water where feasible, consistent with state and county requirements.
Use full loads in sanitizer, sterilizer, dishwasher, and washing machine consistent with infection control requirements.
Overhaul faulty steam traps on sterilizers.
As appliances or fixtures wear out, replace with water-saving models.
Reduce the load on air conditioning units by shutting off air conditioning when and where it is not needed.
Recover condensate from air conditioners, refrigerators, freezers, and ice machines; use it as make-up water.
EXTERIOR AREAS
Inventory outdoor water use for landscaped areas.
Do not water landscape every day; two-to-three times a week is usually sufficient.
Wash autos, buses, and trucks less often.
Discontinue using water to clean sidewalks, driveways, loading docks, and parking lots. Consider using brooms or motorized sweepers.
Stop hosing down sidewalks, driveways, and parking lots.
Wash autos, buses, and trucks less often.
Avoid plant fertilizing and pruning that would stimulate excessive growth.
Remove unhealthy plants so remaining plants can benefit from the water saved.
In many cases, older, established plants require only infrequent irrigation. Look for indications of water need, such as wilt, change of color, or dry soils.
Install soil moisture overrides or timers on sprinkler systems. Time watering, when possible, to occur in the early morning or evening when evaporation is lowest.
Irrigation equipment should apply water uniformly.
Investigate the advantages of installing drip irrigation systems.
Mulch around plants to reduce evaporation and discourage weeds.
Remove thatch and aerate turf to encourage the movement of water to the root zone.
Avoid runoff and make sure sprinklers cover just the lawn or garden, not sidewalks, driveways, or gutters.
271] WATER CONSERVATION IDEAS FOR HOTELS AND MOTELS
Mark Schweiker, Governor Commonwealth of Pennsylvania
David Hess, Secretary Department of Environmental Protection
GENERAL SUGGESTIONS
Increase employee awareness of water conservation.
Seek employee suggestions on water conservation; locate suggestion boxes in prominent areas.
Conduct contests for employees (e.g., posters, slogans, or conservation ideas).
Install signs encouraging water conservation in employee and customer restrooms.
When cleaning with water is necessary, use budgeted amounts.
Read water meter weekly to monitor success of water conservation efforts.
Assign an employee to monitor water use and waste.
Determine the quantity and purpose of water being used.
Determine other methods of water conservation.
BUILDING MAINTENANCE
Check water supply system for leaks and turn off any unnecessary flows.
Repair dripping faucets, showers and continuously running or leaking toilets.
Install flow reducers and faucet aerators in all plumbing fixtures whenever possible.
Reduce the water used in toilet flushing by either adjusting the vacuum flush mechanism or installing toilet tank displacement devices (dams, bottles, or bags).
As appliances or fixtures wear out, replace them with water-saving models.
Shut off water supply to equipment rooms not in use.
Minimize the water used in cooling equipment, such as air compressors, in accordance with the manufacturer recommendations.
Reduce the load on air conditioning units by shutting air conditioning off when and where it is not needed.
Keep hot water pipes insulated.
Avoid excessive boiler and air conditioner blow down. Monitor total dissolved solids levels and blow down only when needed.
Instruct clean-up crew to use less water for mopping.
Switch from wet or steam carpet cleaning methods to dry powder methods.
Change window cleaning schedule from periodic to an on-call/as required basis.
POOLS
Channel splashed-out pool water onto landscaping.
Lower pool water level to reduce amount of water splashed out.
Use a pool cover to reduce evaporation when pool is not being used.
Reduce the amount of water used to clean pool filters.
KITCHEN AREA
Turn off the continuous flow used to clean the drain trays of the coffee/milk/soda beverage island; clean the trays only as needed.
Turn dishwasher off when not in use. Wash full loads only.
Replace spray heads to reduce water flow. If necessary, use ponded water. Use water from steam tables to wash down cooking area.
Do not use running water to melt ice or frozen foods.
Use water-conserving ice makers.
Recycle water where feasible, consistent with state and county requirements.
Recycle rinse water from the dishwater or recirculate it to the garbage disposer.
Presoak utensils and dishes in ponded water instead of using a running water rinse.
Wash vegetables in ponded water; do not let water run in preparation sink.
Use water from steam tables in place of fresh water to wash down the cooking area.
BAR
Do not use running water to melt ice in the sink strainers.
LAUNDRY
Reprogram machines to eliminate a rinse or suds cycle, if possible, and not restricted by health regulations.
Reduce water levels, where possible, to minimize water required per load of washing.
Wash full loads only.
Evaluate wash formula and machine cycles for water use efficiency.
EXTERIOR AREAS
Do not water landscape every day; two-to-three times a week is usually sufficient.
Stop hosing down sidewalks, driveways, and parking lots.
Wash autos, buses, and trucks less often.
Avoid plant fertilizing and pruning that would stimulate excessive growth.
Remove weeds and unhealthy plants so remaining plants can benefit from the water saved.
In many cases, older, established plants require only infrequent irrigation. Look for indications of water need, such as wilting, change of color, or dry soils.
Install soil moisture overrides or timers on sprinkler systems. Time watering, when possible, to occur in the early morning or evening when evaporation is lowest.
Make sure irrigation equipment applies water uniformly. Investigate the advantages of installing drip irrigation systems. Mulch around plants to reduce evaporation and discourage weeds.
Remove thatch and aerate turf to encourage the movement of water to the root zone.
Avoid runoff and make sure sprinklers cover just the lawn or garden, not sidewalks, driveways, or gutters.
WATER CONSERVATION IDEAS FOR LAUNDRIES AND LINEN SUPPLIERS
Mark Schweiker, Governor Commonwealth of Pennsylvania
David Hess, Secretary Department of Environmental Protection
GENERAL SUGGESTIONS
Increase employee awareness of water conservation.
Conduct contests for employees (e.g., posters, slogans, or conservation ideas.
Seek employee suggestions on water conservation; locate suggestion boxes in prominent areas.
Install signs in employee and customer restrooms encouraging water conservation.
When cleaning with water is necessary, use budgeted amounts.
Read water meter weekly to monitor success of water conservation efforts.
Assign an employee to monitor water use and waste.
Determine the quantity and purpose of water being used. Determine other methods of water conservation.
As appliances and fixtures wear out, replace with water-saving models.
BUILDING MAINTENANCE
Reduce the load on air conditioning units by shutting off air conditioning when and where it is not needed.
Check water supply system for leaks and turn off any unnecessary flows.
Repair dripping faucets, showers and continuously running or leaking toilets.
Reduce the water used in toilet flushing by either adjusting the vacuum flush mechanism or installing toilet tank displacement devices (dams, bottles, or bags).
As appliances or fixtures wear out, replace them with water-saving models.
Shut off water supply to equipment rooms not in use.
Keep hot water pipes insulated.
Avoid excessive boiler and air conditioner blow down. Monitor total dissolved solids levels and blow down only when needed.
Install flow reducers and faucet aerators in all plumbing fixtures whenever possible.
Avoid excessive filter or softener back flush. Back flush only when needed.
OPERATIONS
Recycle water where feasible consistent with state and county requirements.
Reprogram machines to eliminate a rinse or suds cycle, if possible, and if not restricted by health regulations.
Reduce water levels to minimize required water per load.
Evaluate wash formula and machine cycles for water-use efficiency.
Wash full loads only.
EXTERIOR AREAS
Inventory outdoor water use for landscaped areas.
Water landscapes only when needed; two-to-three times a week is usually sufficient.
Make sure water does not run into the gutters, streets, or alleys.
Use controllers on sprinkler systems.
Wash autos, buses, and trucks less often.
Do not water on windy days.
Time watering, when possible, to occur in the early morning or evening when evaporation is lowest.
WATER CONSERVATION IDEAS FOR RESTAURANTS
Mark Schweiker, Governor Commonwealth of Pennsylvania
David Hess, Secretary Department of Environmental Protection
GENERAL SUGGESTIONS
Increase employee awareness of water conservation.
Seek employee suggestions on water conservation; locate suggestion boxes in prominent areas.
Conduct contests.
Install signs encouraging water conservation in employee and customer restrooms.
When cleaning with water is necessary, use budgeted amounts.
Read water meter weekly to monitor success of water conservation efforts.
Assign an employee to monitor water use and waste.
Determine the quantity and purpose of water being used.
Determine other methods of water conservation.
Provide table signs urging water conservation.
Serve water only when requested by customer.
BUILDING MAINTENANCE
Reduce the load on air conditioning units by shutting off air conditioning when and where it is not needed.
Check water supply system for leaks and turn off any unnecessary flows.
Repair dripping faucets, showers and continuously running or leaking toilets.
Install flow reducers and faucet aerators in all plumbing fixtures whenever possible.
Reduce the water used in toilet flushing by either adjusting the vacuum flush mechanism or installing toilet tank displacement devices (dams, bottles, or bags).
As appliances or fixtures wear out, replace them with water-saving models.
Shut off water supply to equipment rooms not in use.
Minimize the water used in cooling equipment, such as air compressors, in accordance with the manufacturer recommendations.
Keep hot water pipes insulated.
Avoid excessive boiler and air conditioner blow down. Monitor total dissolved solids levels and blow down only when needed.
Switch from wet or steam carpet cleaning methods to dry powder methods.
Instruct clean-up crew to use less water for mopping.
Change window cleaning schedule from periodic to an on-call/as required basis.
KITCHEN AREA
Turn off the continuous flow used to clean the drain trays of the coffee/milk/soda beverage island; clean the trays only as needed.
Turn dishwasher off when not in use. Wash full loads only.
Replace spray heads in dishwasher to reduce water flow. Use water from steam tables to wash down cooking area.
Do not use running water to melt ice or frozen foods.
Use water-conserving ice makers.
Recycle water where feasible, consistent with state and county requirements.
Recycle rinse water from the dishwasher or recirculate it to the garbage disposal.
Rinse utensils and dishes in ponded water.
Wash vegetables in ponded water; do not let water run in preparation sink.
BAR
Do not use running water to melt ice in the sink strainers.
EXTERIOR AREAS
Water landscapes only when needed; two-to-three times a week is usually sufficient.
Stop hosing down sidewalks, driveways, and parking lots.
Wash autos, buses, and trucks less often.
Avoid plant fertilizing and pruning that would stimulate excessive growth.
Remove weeds and unhealthy plants so remaining plants can benefit from the water saved.
In many cases, older, established plants require only infrequent irrigation. Look for indications of water need, such as wilting, change of color, or dry soils.
Install soil moisture overrides or timers on sprinkler systems. Time watering, when possible, to occur in the early morning or evening when evaporation is lowest.
Irrigation equipment should apply water uniformly.
Investigate the advantages of installing drip irrigation systems.
Mulch around plants to reduce evaporation and discourage weeds.
Remove thatch and aerate turf to encourage the movement of water to the root zone.
Avoid runoff and make sure sprinklers cover just the lawn or garden, not sidewalks, driveways, or gutters
272] WATER CONSERVATION IDEAS FOR SCHOOLS AND COLLEGES
Mark Schweiker, Governor Commonwealth of Pennsylvania
David Hess, Secretary Department of Environmental Protection
GENERAL SUGGESTIONS
· Increase employee, faculty, and student awareness of water conservation.
· Conduct contests for employees and students (e.g., posters, slogans, or conservation ideas).
· Seek employee suggestions on water conservation; locate suggestion boxes in prominent areas.
· Install signs in all restrooms encouraging water conservation.
· When cleaning with water is necessary, use budgeted amounts.
· Read water meter weekly to monitor success of water conservation efforts.
· Assign an employee to monitor water use and waste.
· Determine the quantity and purpose of water being used.
· Determine other methods of water conservation.
BUILDING MAINTENANCE
· Check water supply system for leaks.
· Turn off any unnecessary flows.
· Repair dripping faucets, showers and continuously running or leaking toilets.
· Install flow reducers and faucet aerators in all plumbing fixtures whenever possible.
· Reduce the water used in toilet flushing by either adjusting the vacuum flush mechanism or installing toilet tank displacement devices (dams, bottles, or bags).
· As appliances or fixtures wear out, replace them with water-saving models.
· Shut off water supply to equipment rooms not in use.
· Minimize the water used in cooling equipment, such as air compressors, in accordance with the manufacturer recommendations.
· Reduce the load on air conditioning units by shutting air conditioning off when and where it is not needed.
· Keep hot water pipes insulated.
· Avoid excessive boiler and air conditioner blow down. Monitor total dissolved solids levels and blow down only when needed.
· Instruct clean-up crew to use less water for mopping.
· Change window cleaning schedule from periodic to an on-call/as required basis.
KITCHEN AND LAUNDRY AREAS
· Turn off the continuous flow used to clean the drain trays of the coffee/milk/soda beverage island; clean the trays only as needed.
· Turn dishwasher off when not in use. Wash full loads only.
Replace spray heads to reduce water flow.
· Recycle rinse water from the dishwater or recirculate it to the garbage disposal.
Do not use running water to melt ice or frozen foods. If necessary, use ponded water.
· Use water-conserving ice makers.
Presoak utensils and dishes in ponded water instead of using a running water rinse.
· Wash vegetables in ponded water; do not let water run in preparation sink.
Use water from steam tables in place of fresh water to wash down the cooking area.
· Reprogram machines to eliminate a rinse or suds cycle, if possible, and if not restricted by health regulations.
· Only wash full loads of clothes.
· Evaluate wash formula and machine cycles for water use efficiency.
POOL
· Channel splashed-out pool water into landscaping.
· Lower pool water to reduce amount of water splashed out.
· Use a pool cover to reduce evaporation when pool is not being used. Reduce amount of water used to clean pool filters.
EXTERIOR AREAS
· Inventory outdoor water use for landscaped areas.
· Water landscape only when needed; two-to-three times a week is usually sufficient. Do not water landscape every day.
· Wash autos, buses, and trucks less often.
· Discontinue using water to clean sidewalks, driveways, loading docks, and parking lots. Consider using brooms or motorized sweepers.
· Avoid landscaped fertilizing and pruning stimulating excessive growth.
· Remove weeds unhealthy plants so remaining plants can benefit from the water saved.
In many cases, older, established plants require only infrequent irrigation. Look for indications of water need, such as wilting, change of color, or dry soils.
· Install soil moisture overrides or timers on sprinkler systems.
· Time watering, when possible, to occur in the early morning or evening when evaporation is lowest.
· Make sure irrigation equipment applies water uniformly. Investigate the advantages of installing drip irrigation systems.
· Mulch around plants reducing evaporation and discouraging weeds.
· Remove thatch and aerate turf encouraging movement of water to the root zone.
Avoid runoff and make sure sprinklers cover just the lawn or garden, not sidewalks, driveways, or gutters.
273] ] Water Conflict Chronology1
September 2000 Version
Compiled by: Peter Gleick,
Pacific Institute for Studies in Development, Environment, and Security
Date Parties Involved Basis of Conflict Violent Conflict? Description Sources
1503 Florence and Pisa warring states Military tool Yes Leonardo da Vinci and Machievelli plan to divert Arno River away from Pisa during conflict between Pisa and Florence. Honan 1996
1642 China; Ming Dynasty Military tool Yes The Huang He's dikes have been breached for military purposes. In 1642, "toward the end of the Ming dynasty (1368-1644), General Gao Mingheng used the tactic near Kaifeng in an attempt to suppress a peasant uprising." Hillel 1991
1863 United States Civil War Military tool Yes General U.S. Grant, during the Civil War campaign against Vicksburg, cut levees in the battle against the Confederates. Grant1885, Barry 1997
1898 Egypt; France; Britain Military and political tool, Control of water resources Military maneuvers Military conflict nearly ensues between Britain and France in 1898 when a French expedition attempted to gain control of the headwaters of the White Nile. While the parties ultimately negotiates a settlement of the dispute, the incident has been characterized as having "dramatized Egypt's vulnerable dependence on the Nile, and fixed the attitude of Egyptian policy-makers ever since." Moorhead 1960
1924 Owens Valley, Los Angeles, California Political tool, Control of water resources, Terrorism, and Development dispute Yes The Los Angeles Valley aqueduct/pipeline suffers repeated bombings in an effort to prevent diversions of water from the Owens Valley to Los Angeles. Reisner 1986, 1993
1935 California, Arizona Political tool, development dispute Military maneuvers Arizona calls out the National Guard and militia units to the border with California to protest the construction of Parker Dam and diversions from the Colorado River; dispute ultimately is settled in court. Reisner 1986, 1993
1938 China and Japan Military tool, Military target Yes Chiang Kai-shek orders the destruction of flood-control dikes of the Huayuankou section of the Huang He (Yellow) river to flood areas threatened by the Japanese army. West of Kaifeng dikes are destroyed with dynamite, spilling water across the flat plain. The flood destroyed part of the invading army and its heavy equipment was mired in thick mud, though Wuhan, the headquarters of the Nationalist government was taken in October. The waters flooded an area variously estimated as between 3,000 and 50,000 square kilometers, and killed Chinese estimated in numbers between "tens of thousands" and "one million." Hillel 1991, Yang Lang 1989, 1994
1940-1945 Multiple parties Military target Yes Hydroelectric dams routinely bombed as strategic targets during World War II. Gleick 1993
1943 Britain, Germany Military target Yes British Royal Air Force bombed dams on the Mohne, Sorpe, and Eder Rivers, Germany (May 16, 17). Mohne Dam breech killed 1,200, destroyed all downstream dams for 50 km. Kirschner 1949
1944 Germany, Italy, Britain, United States Military tool Yes German forces used waters from the Isoletta Dam (Liri River) in January and February to successfully destroy British assault forces crossing the Garigliano River (downstream of Liri River). The German Army then dammed the Rapido River, flooding a valley occupied by the American Army. Corps of Engineers 1953
1944 Germany, Italy, Britain, United States Military tool Yes German Army flooded the Pontine Marches by destroying drainage pumps to contain the Anzio beachhead established by the Allied landings in 1944. Over 40 square miles of land were flooded; a 30-mile stretch of landing beaches was rendered unusable for amphibious support forces. Corps of Engineers 1953
1944 Germany, Allied forces Military tool Yes Germans flooded the Ay River, France (July) creating a lake two meters deep and several kilometers wide, slowing an advance on Saint Lo, a German communications center in Normandy. Corps of Engineers 1953
1944 Germany, Allied forces Military tool Yes Germans flooded the Ill River Valley during the Battle of the Bulge (winter 1944-45) creating a lake 16 kilometers long, 3-6 kilometers wide, and 1-2 meters deep, greatly delaying the American Army’s advance toward the Rhine. Corps of Engineers 1953
1947 onwards Bangladesh, India Development disputes, Control of water resources No Partition divides the Ganges River between Bangladesh and India; construction of the Farakka barrage by India, beginning in 1962, increases tension; short-term agreements settle dispute in 1977-82, 1982-84, and 1985-88, and thirty-year treaty is signed in 1996. Butts 1997, Samson & Charrier 1997
1947-1960s India, Pakistan Development disputes, Control of water resources, and Political tool No Partition leaves Indus basin divided between India and Pakistan; disputes over irrigation water ensue, during which India stems flow of water into irrigation canals in Pakistan; Indus Waters Agreement reached in 1960 after 12 years of World Bank-led negotiations. Bingham et al. 1994, Wolf 1997
1948 Arabs, Israelis Military tool Yes Arab forces cut of West Jerusalem’s water supply in first Arab-Israeli war. Wolf 1995, 1997
1950s Korea, United States, others Military target Yes Centralized dams on the Yalu River serving North Korea and China are attacked during Korean War. Gleick 1993
1951 Korea, United Nations Military tool and Military target Yes North Korea released flood waves from the Hwachon Dam damaging floating bridges operated by UN troops in the Pukhan Valley. U.S. Navy plans were then sent to destroy spillway crest gates. Corps of Engineers 1953
1951 Israel, Jordan, Syria Political tool, Military tool, Development disputes Yes Jordan makes public its plans to irrigate the Jordan Valley by tapping the Yarmouk River; Israel responds by commencing drainage of the Huleh swamps located in the demilitarized zone between Israel and Syria; border skirmishes ensue between Israel and Syria. Wolf 1997, Samson & Charrier 1997
1953 Israel, Jordan, Syria Development dispute, Military target, Political tool Yes Israel begins construction of its National Water Carrier to transfer water from the north of the Sea of Galilee out of the Jordan basin to the Negev Desert for irrigation. Syrian military actions along the border and international disapproval lead Israel to move its intake to the Sea of Galilee. Samson & Charrier 1997
1958 Egypt, Sudan Military tool, Political tool, Control of water resources Yes Egypt sends an unsuccessful military expedition into disputed territory amidst pending negotiations over the Nile waters, Sudanese general elections, and an Egyptian vote on Sudan-Egypt unification; Nile Water Treaty signed when pro-Egyptian government elected in Sudan. Wolf 1997
1960s North Vietnam, United States Military target Yes Irrigation water supply systems in North Vietnam are bombed during Vietnam War. 661 sections of dikes damaged or destroyed. Gleick 1993, Zemmali 1995
1962 to 1967 Brazil; Paraguay Military tool, Political tool, Control of water resources Military maneuvers Negotiations between Brazil and Paraguay over the development of the Paraná River are interrupted by a unilateral show of military force by Brazil in 1962, which invades the area and claims control over the Guaira Falls site. Military forces were withdrawn in 1967 following an agreement for a joint commission to examine development in the region. Murphy and Sabadell 1986
1963-1964 Ethiopia, Somalia Development dispute, Military tool, Political tool Yes Creation of boundaries in 1948 leaves Somali nomads under Ethiopian rule; border skirmishes occur over disputed territory in Ogaden desert where critical water and oil resources are located; cease-fire is negotiated only after several hundred are killed. Wolf 1997
1965-1966 Israel, Syria Military tool, Political tool, Control of water resources, Development dispute Yes Fire is exchanged over "all-Arab" plan to divert the Jordan River headwaters and presumably preempt Israeli National Water Carrier; Syria halts construction of its diversion in July 1966. Wolf 1995, 1997
1966-1972 Vietnam, US Military tool Yes U.S. tries cloud-seeding in Indochina to stop flow of materiel along Ho Chi Minh trail. Plant 1995
1967 Israel, Syria Military target and tool Yes Israel destroys the Arab diversion works on the Jordan River headwaters. During Arab-Israeli War Israel occupies Golan Heights, with Banias tributary to the Jordan; Israel occupies West Bank. Gleick 1993, Wolf 1995, 1997, Wallenstein & Swain 1997
1969 Israel, Jordan Military target and tool Yes Israel, suspicious that Jordan is overdiverting the Yarmouk, leads two raids to destroy the newly-built East Ghor Canal; secret negotiations, mediated by the US, lead to an agreement in 1970. Samson & Charrier 1997
1970s Argentina, Brazil, Paraguay Political goal, Development dispute No Brazil and Paraguay announce plans to construct a dam at Itaipu on the Paraná River, causing Argentina concern about downstream environmental repercussions and the efficacy of their own planned dam project downstream. Argentina demands to be consulted during the planning of Itaipu but Brazil refuses. An agreement is reached in 1979 that provides for the construction of both Brazil and Paraguay’s dam at Itaipu and Argentina’s Yacyreta dam. Wallenstein & Swain 1997
1974 Iraq, Syria Military target, Military tool, Political tool, Development dispute Military maneuvers Iraq threatens to bomb the al-Thawra dam in Syria and massed troops along the border, alleging that the dam had reduced the flow of Euphrates River water to Iraq. Gleick 1994
1975 Iraq, Syria Development dispute, Military tool, Political tool Military maneuvers As upstream dams are filled during a low-flow year on the Euphrates, Iraqis claim that flow reaching its territory is "intolerable" and asks the Arab League to intervene. Syrians claim they are receiving less than half the river’s normal flow and pull out of an Arab League technical committee formed to mediate the conflict. In May Syria closes its airspace to Iraqi flights and both Syrian and Iraq reportedly transfer troops to their mutual border. Saudi Arabia successfully mediates the conflict. Gleick 1993, 1994, Wolf 1997
1975 Angola, South Africa Military goal Yes South African troops move into Angola to occupy and defend the Ruacana hydropower complex, including the Gové Dam on the Kunene River. Goal is to take possession of and defend the water resources of southwestern Africa and Namibia. Meissner 2000
1978-onwards Egypt, Ethiopia Development dispute, Political tool No Long standing tensions over the Nile, especially the Blue Nile, originating in Ethiopia. Ethiopia’s proposed construction of dams on the headwaters of the Blue Nile leads Egypt to repeatedly declare the vital importance of water. "The only matter that could take Egypt to war again is water" (Anwar Sadat-1979). "The next war in our region will be over the waters of the Nile, not politics" (Boutrous Ghali-1988). Gleick 1991, 1994
1981 Iran, Iraq Military target and tool Yes Iran claims to have bombed a hydroelectric facility in Kurdistan, thereby blacking out large portions of Iraq, during the Iran-Iraq War. Gleick 1993
1980-1988 Iran, Iraq Military tool Yes Iran diverts water to flood Iraqi defense positions. Plant 1995
1988 Angola, South Africa, Cuba Military goal, military target Yes Cuban and Angolan forces launch an attack on Calueque Dam via land and then air. Considerable damage inflicted on dam wall; power supply to dam cut. Water pipeline to Owamboland cut and destroyed. Meissner 2000
1982 Israel, Lebanon, Syria Military tool Yes Israel cuts off the water supply of Beirut during siege. Wolf 1997
1986 North Korea, South Korea Military tool No North Korea’s announcement of its plans to build the Kumgansan hydroelectric dam on a tributary of the Han River upstream of Seoul raises concerns in South Korea that the dam could be used as a tool for ecological destruction or war. Gleick 1993
1986 Lesotho, South Africa Military goal; Control of water resources YesS outh Africa supports coup in Lesotho over support for ANC and anti-apartheid, and water. New government in Lesotho then quickly signs Lesotho Highlands water agreement. American University 2000b
1990 South Africa Development dispute, Control of water resources No Pro-apartheid council cuts off water to the Wesselton township of 50,000 blacks following protests over miserable sanitation and living conditions. Gleick 1993
1990 Iraq, Syria, Turkey Development dispute, Military tool, Political tool No The flow of the Euphrates is interrupted for a month as Turkey finishes construction of the Ataturk Dam, part of the Grand Anatolia Project. Syria and Iraq protest that Turkey now has a weapon of war. In mid-1990 Turkish president Turgut Ozal threatens to restrict water flow to Syria to force it to withdraw support for Kurdish rebels operating in southern Turkey. Gleick 1993 & 1995
1991-present Karnataka, Tamil Nadu (India) Development dispute, Control of water resources Yes Violence erupts when Karnataka rejects an Interim Order handed down by the Cauvery Waters Tribunal, empaneled by the Indian Supreme Court. The Tribunal was established in 1990 to settle two decades of dispute between Karnataka and Tamil Nadu over irrigation rights to the Cauvery River. Gleick 1993, Butts 1997, American University 2000a
1991 Iraq, Kuwait, US Military target Yes During the Gulf War, Iraq destroys much of Kuwait’s desalination capacity during retreat. Gleick 1993
1991 Iraq, Turkey, United Nations Military tool Yes Discussions are held at the United Nations about using the Ataturk Dam in Turkey to cut off flows of the Euphrates to Iraq. Gleick 1993
1991 Iraq, Kuwait, US Military target Yes Baghdad’s modern water supply and sanitation system are intentionally targeted by Allied coalition. Gleick 1993
1992 Czechoslovakia, Hungary Political tool, Development dispute Military maneuvers Hungary abrogates a 1977 treaty with Czechoslovakia concerning construction of the Gabcikovo/Nagymaros project based on environmental concerns. Slovakia continues construction unilaterally, completes the dam, and diverts the Danube into a canal inside the Slovakian republic. Massive public protest and movement of military to the border ensue; issue taken to the International Court of Justice. Gleick 1993
1992 Bosnia, Bosnian Serbs Military tool Yes The Serbian siege of Sarajevo, Bosnia and Herzegovina, includes a cutoff of all electrical power and the water feeding the city from the surrounding mountains. The lack of power cuts the two main pumping stations inside the city despite pledges from Serbian nationalist leaders to United Nations officials that they would not use their control of Sarajevo's utilities as a weapon. Bosnian Serbs take control of water valves regulating flow from wells that provide more than 80 percent of water to Sarajevo; reduced water flow to city is used to ‘smoke out’ Bosnians. Burns 1992, Husarska 1995
1993-present Iraq Military tool No To quell opposition to his government, Saddam Hussein reportedly poisons and drains the water supplies of southern Shiite Muslims, the Ma'dan. The European Parliament and UN Human Rights Commission deplore use of water as weapon in region. Gleick 1993, American University 2000c
1993 Yugoslavia Military target and tool Yes Peruca Dam intentionally destroyed during war. Gleick 1993
1995 Ecuador, Peru Military and political tool Yes Armed skirmishes arise in part because of disagreement over the control of the headwaters of Cenepa River. Wolf argues that this is primarily a border dispute simply coinciding with location of a water resource. Samson & Charrier 1997, Wolf 1997
1997 Singapore, Malaysia Political tool No Malaysia supplies about half of Singapore’s water and in 1997 threatened to cut off that supply in retribution for criticisms by Singapore of policy in Malaysia. Zachary 1997
1998 Tajikistan Terrorism, Political tool Potential On November 6, a guerrilla commander threatened to blow up a dam on the Kairakkhum channel if political demands are not met. Col. Makhmud Khudoberdyev made the threat, reported by the ITAR-Tass News Agency. WRR 1998
1999 Lusaka, Zambia Terrorism, Political tool Yes Bomb blast destroyed the main water pipeline, cutting off water for the city of Lusaka, population 3 million. FTGWR 1999
1999 Yugoslavia Military target Yes Belgrade reported that NATO planes had targeted a hydroelectric plant during the Kosovo campaign. Reuters 1999a
1999 Bangladesh Development dispute, Political tool Yes 50 hurt during strikes called to protest power and water shortages. Protest led by former Prime Minister Begum Khaleda Zia over deterioration of public services and in law and order. Ahmed 1999
1999 Yugoslavia Military target Yes NATO targets utilities and shuts down water supplies in Belgrade. NATO bombs bridges on Danube, disrupting navigation. Reuters 1999b
1999 Yugoslavia Political tool Yes Yugoslavia refuses to clear war debris on Danube (downed bridges) unless financial aid for reconstruction is provided; European countries on Danube fear flooding due to winter ice dams will result. Diplomats decry environmental blackmail. Simons 1999
1999 Kosovo Political tool Yes Serbian engineers shut down water system in Pristina prior to occupation by NATO. Reuters 1999c
1999 Angola Terrorism/ Political tool Yes 100 bodies were found in four drinking water wells in central Angola. International Herald Tribune 1999
1999 Puerto Rico, U.S. Political tool No Protesters blocked water intake to Roosevelt Roads Navy Base in opposition to U.S. military presence and Navy’s use of the Blanco River, following chronic water shortages in neighboring towns. New York Times 1999
1999 East Timor Military tool, Political tool, terrorism Yes Militia opposing East Timor independence kill pro-independence supporters and throw bodies in water well. BBC 1999
1999 Kosovo Terrorism/ Political tool Yes Contamination of water supplies/wells by Serbs disposing of bodies of Kosovar Albanians in local wells. CNN 1999
1999-2000 Namibia, Botswana, Zambia Military goal No Sedudu/Kasikili Island, in the Zambezi/Chobe River. Dispute over border and access to water. Presented to the International Court of Justice ICJ 1999.
Notes:
1. Conflicts may stem from the drive to possess or control another nation’s water resources, thus making water systems and resources a political or military goal. Inequitable distribution and use of water resources, sometimes arising from a water development, may lead to development disputes, heighten the importance of water as a strategic goal or may lead to a degradation of another’s source of water. Conflicts may also arise when water systems are used as instruments of war, either as targets or tools. These distinctions are described in detail in Gleick (1993, 1998).
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274] Important water glossary
acid mine drainage - Low pH drainage water from certain mines usually caused by the oxidation of sulphides to sulphuric acid. Mine drainage can also contain high concentration of metal ions.
acid rain - Rainfall with a pH of less than 7.0. One source is the combining of rain and sulphur dioxide emissions, which are a by-product of combustion of fossil fuels. Also referred to as acid deposition and wet deposition.
algae - Simple rootless plants that grow in sunlit waters in relative proportion to the amounts of nutrients available. They can affect water quality adversely by lowering the dissolved oxygen in the water. They are food for fish and small aquatic animals.
algae blooms - Rapid growth of algae on the surface of lakes, streams, or ponds; stimulated by nutrient enrichment.
alkali - Any strongly basic substance of hydroxide and carbonate, such as soda, potash, etc., that is soluble in water and increases the pH of a solution.
aquatic ecosystem - Basic ecological unit composed of living and nonliving elements interacting in an aqueous milieu.
aquifer - The underground layer of water-soaked sand and rock that acts as a water source for a well; described as artesian (confined) or water table (unconfined).
arid - Describes regions where precipitation is insufficient in quantity for most crops and where agriculture is impractical without irrigation.
atmosphere - The layer of gases surrounding the earth and composed of considerable amounts of nitrogen, hydrogen, and oxygen.
atmospheric water - Water present in the atmosphere either as a solid (snow, hail), liquid (rain) or gas (fog, mist).
B
bioaccumulation (bioconcentation) - A term used to describe a process that occurs when levels of toxic substances increase in an organism over time, due to continued exposure.
biodegradable - Capable of being broken down by living organisms into inorganic compounds.
biological diversity (biodiversity) -The variety of different species, the genetic variability of each species, and the variety of different ecosystems that they form.
biomagnification (biological magnification) - A cumulative increase in the concentrations of a persistent substance in successively higher levels of the food chain.
biota - Collectively, the plants, microorganisms, and animals of a certain area or region.
bog - A type of wetland that accumulates appreciable peat deposits. It depends primarily on precipitation for its water source and is usually acidic and rich in plant matter, with a conspicuous mat or living green moss.
boundary water - A river or lake that is part of the boundary between two or more countries or provinces that have rights to the water.
C
climate - Meteorological elements that characterize the average and extreme conditions of the atmosphere over a long period of time at any one place or region of the earth's surface.
climate change - The slow variations of climatic characteristics over time at a given place.
coliform bacteria - A group of bacteria used as an indicator of sanitary quality in water. Exposure to these organisms in drinking water causes diseases such as cholera.
combined sewers - A sewer that carries both sewage and storm water runoff.
condensation - The process by which a vapour becomes a liquid or solid; the opposite of evaporation. In meteorological usage, this term is applied only to the transformation from vapour to liquid.
conservation - The continuing protection and management of natural resources in accordance with principles that assure their optimum long-term economic and social benefits.
consumptive use - The difference between the total quantity of water withdrawn from a source for any use and the quantity of water returned to the source; e.g., the release of water into the atmosphere; the consumption of water by humans, animals, and plants; and the incorporation of water into the products of industrial or food processing.
contaminant - Any physical, chemical, biological, or radiological substance or matter that has an adverse affect on air, water, or soil.
cooling tower - A structure that helps remove heat from water used as a coolant; e.g., in electric power generating plants.
cubic metre per second (m3/s) - A unit expressing rate of discharge, typically used in measuring streamflow. One cubic metre per second is equal to the discharge in a stream of a cross section one metre wide and one metre deep, flowing with an average velocity of one metre per second.
D
dam - A structure of earth, rock, concrete, or other materials designed to retain water, creating a pond, lake, or reservoir.
delta - A fan-shaped alluvial deposit at a river mouth formed by the deposition of successive layers of sediment.
demand - The numerical expression of the desire for goods and services associated with an economic standard for acquiring them.
depletion - Loss of water from surface water reservoirs or
groundwater aquifers at a rate greater than that of recharge.
dioxin - Any of a family of compounds known chemically as dibenzo-p-dioxins. Concern about them arises from their potential toxicity and contamination in commercial products.
discharge - In the simplest form, discharge means outflow of water. The use of this term is not restricted as to course or location, and it can be used to describe the flow of water from a pipe or from a drainage basin. Other words related to it are runoff, streamflow, and yield.
dissolved oxygen (DO) - The amount of oxygen freely available in water and necessary for aquatic life and the oxidation of organic materials.
dissolved solids (DS) - Very small pieces of organic and inorganic material contained in water. Excessive amounts make water unfit to drink or limit its use in industrial processes.
diversion - The transfer of water from a stream, lake, aquifer, or other source of water by a canal, pipe, well, or other conduit to another watercourse or to the land, as in the case of an irrigation system.
domestic use - The quantity of water used for household purposes such as washing, food preparation, and bathing.
drainage basin - See: Watershed.
dredgeate - The material excavated from lake, river, or channel bottoms during dredging.
dredging - The removal of material from the bottom of water bodies using a scooping machine. This disturbs the ecosystem and causes silting that can kill aquatic life.
drought - A continuous and lengthy period during which no significant precipitation is recorded.
dry deposition - Emissions of sulphur and nitrogen oxides that, in the absence of water in the atmosphere (i.e., rain), settle to the ground as particulate matter.
dyke - An artificial embankment constructed to prevent flooding.
E
ecosystem - A system formed by the interaction of a group of organisms and their environment.
effluent - The sewage or industrial liquid waste that is released into natural water by sewage treatment plants, industry, or septic tanks.
environment - All of the external factors, conditions, and influences that affect an organism or a community.
environmental assessment - The critical appraisal of the likely effects of a proposed project, activity, or policy on the environment, both positive and negative.
environmental monitoring - The process of checking, observing, or keeping track of something for a specified period of time or at specified intervals.
erosion - The wearing down or washing away of the soil and land surface by the action of water, wind, or ice.
estuary - Regions of interaction between rivers and nearshore ocean waters, where tidal action and river flow create a mixing of fresh water and saltwater. These areas may include bays, mouths of rivers, salt marshes, and lagoons. These brackish water ecosystems shelter and feed marine life, birds, and wildlife.
eutrophic lake - Shallow, murky bodies of water that have excessive concentrations of plant nutrients causing excessive algal production.
eutrophication - The natural process by which lakes and ponds become enriched with dissolved nutrients, resulting in increased growth of algae and other microscopic plants.
evaporation - The process by which a liquid changes to a vapour.
evapotranspiration - The loss of water from a land area through evaporation from the soil and through plant transpiration.
F
fen - A type of wetland that accumulates peat deposits. Fens are less acidic than bogs, deriving most of their water from groundwater rich in calcium and magnesium.
flood - The temporary inundation of normally dry land areas resulting from the overflowing of the natural or artificial confines of a river or other body of water.
flood damage - The economic loss caused by floods, including damage by inundation, erosion, and/or sediment deposition. Damages also include emergency costs and business or financial losses. Evaluation may be based on the cost of replacing, repairing, or rehabilitating; the comparative change in market or sales value; or the change in the income or production caused by flooding.
flood forecasting - Prediction of stage, discharge, time of occurrence, and duration of a flood, especially of peak discharge at a specified point on a stream, resulting from precipitation and/or snowmelt.
flood fringe - The portion of the floodplain where water depths are shallow and velocities are low.
flood peak - The highest magnitude of the stage of discharge attained by a flood. Also called peak stage or peak discharge.
floodplain - Any normally dry land area that is susceptible to being inundated by water from any natural source. This area is usually low land adjacent to a stream or lake.
floodproofing - Any combination of structural and nonstructural additions, changes, or adjustments to structures that reduce or eliminate flood damage.
floodway - The channel of a river or stream and those parts of the adjacent floodplain adjoining the channel that are required to carry and discharge the base flood.
flow - The rate of water discharged from a source; expressed in volume with respect to time, e.g., m3/s.
flow augmentation - The addition of water to a stream, especially to meet instream flow needs.
food chain - A sequence of organisms, each of which uses the next, lower member of the sequence as a food source.
food web - The complex intermeshing of individual food chains in an ecosystem.
fresh water - Water that generally contains less than 1000 milligrams per litre of dissolved solids such as salts, metals, nutrients, etc.
G
glacier - A huge mass of ice, formed on land by the compaction and re-crystallization of snow, that moves very slowly downslope or outward due to its own weight.
greenhouse effect - The warming of the earth's atmosphere caused by a build-up of carbon dioxide or other trace gases; it is believed by many scientists that this build-up allows light from the sun's rays to heat the earth but prevents a counterbalancing loss of heat.
groundwater - The supply of fresh water found beneath the earth's surface (usually in aquifers) that is often used for supplying wells and springs.
groundwater recharge - The inflow to an aquifer.
H
habitat - The native environment where a plant or animal naturally grows or lives.
hazardous waste - Waste that poses a risk to human health or the environment and requires special disposal techniques to make it harmless or less dangerous.
hydroelectricity - Electric energy produced by water-powered turbine generators.
hydrologic cycle - The constant circulation of water from the sea, through the atmosphere, to the land, and back to the sea by over-land, underground, and atmospheric routes.
hydrology - The science of waters of the earth; water's properties, circulation, principles, and distribution.
I
infiltration - The movement of water into soil or porous rock. Infiltration occurs as water flows through the larger pores of rock or between soil particles under the influence of gravity, or as a gradual wetting of small particles by capillary action.
inflow - The entry of extraneous rainwater into a sewer system from sources other than infiltration, such as basement drains, sewer holes, storm drains, and street washing.
inorganic - Matter other than plant or animal and not containing a combination of carbon, hydrogen, and oxygen, as in living things.
instream use - Uses of water within the stream channel, e.g., fish and other aquatic life, recreation, navigation, and hydroelectric power production.
integrated resource planning - The management of two or more resources in the same general area; commonly includes water, soil, timber, grazing land, fish, wildlife, and recreation.
interbasin transfer - The diversion of water from one drainage basin to one or more other drainage basins.
irrigation - The controlled application of water to cropland, hayland, and/or pasture to supplement that supplied through nature.
J
jökulhlaup - Destructive flood that occurs as the result of the rapid ablation of ice by volcanic activity beneath the ice of a large glacier.
K
kilowatt (kW) - A unit of electrical power equal to 1000 watts or 1.341 horsepower.
kilowatt hour (kWh) - One kilowatt of power applied for one hour.
L
lagoon - (1) A shallow pond where sunlight, bacterial action, and oxygen work to purify wastewater. (2) A shallow body of water, often separated from the sea by coral reefs or sandbars.
lake - Any inland body of standing water, usually fresh water, larger than a pool or pond; a body of water filling a depression in the earth's surface.
leaching - The removal of soluble organic and inorganic substances from the topsoil downward by the action of percolating water.
litre - The basic unit of measurement for volume in the metric system; equal to 61.025 cubic inches or 1.0567 liquid quarts.
M
marsh - A type of wetland that does not accumulate appreciable peat deposits and is dominated by herbaceous vegetation. Marshes may be either fresh water or saltwater and tidal or non-tidal.
megawatt - A unit of electricity equivalent to 1000 kilowatts.
model - A simulation, by descriptive, statistical, or other means, of a process or project that is difficult or impossible to observe directly.
N
NAPLs - Nonaqueous phase liquids; i.e., chemical solvents such as trichloroethylene (TCE) or carbon tetrachloride – often toxic. Many of the most problematic NAPLs are DNAPLs – dense nonaqueous phase liquids.
natural flow - The flow of a stream as it would be if unaltered by upstream diversion, storage, import, export, or change in upstream consumptive use caused by development.
navigable waters - Traditionally, waters sufficiently deep and wide for navigation by all, or specific sizes of, vessels.
non-renewable resources - Natural resources that can be used up completely or else used up to such a degree that it is economically impractical to obtain any more of them; e.g., coal, crude oil, and metal ores.
nutrient - As a pollutant, any element or compound, such as phosphorus or nitrogen, that fuels abnormally high organic growth in aquatic ecosystems (e.g., eutrophication of a lake).
O
oligotrophic lake - Deep, clear lakes with low nutrient supplies. They contain little organic matter and have a high dissolved oxygen level.
organic - (1) Referring to or derived from living organisms. (2) In chemistry, any compound containing carbon.
organism - A living thing.
P
parts per million (PPM) - The number of "parts" by weight of a substance per million parts of water. This unit is commonly used to represent pollutant concentrations. Large concentrations are expressed in percentages.
pathogenic microorganisms - Microorganisms that can cause disease in other organisms or in humans, animals, and plants.
percolation - The movement of water downward through the subsurface to the zone of saturation.
permafrost - Perennially frozen layer in the soil, found in alpine, arctic, and antarctic regions.
pesticide - A substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest. Also, any substance or mixture of substances intended to regulate plant or leaf growth. Pesticides can accumulate in the food chain and/or contaminate the environment if misused.
pH - An expression of both acidity and alkalinity on a scale of 0 to 14, with 7 representing neutrality; numbers less than 7 indicate increasing acidity and numbers greater than 7 indicate increasing alkalinity.
photosynthesis - The manufacture by plants of carbohydrates and oxygen from carbon dioxide and water in the presence of chlorophyll, using sunlight as an energy source.
phytoplankton - Usually microscopic aquatic plants, sometimes consisting of only one cell.
plankton - Tiny plants and animals that live in water.
polychlorinated biphenyls (PCBs) - A group of chemicals found in industrial wastes.
pond - A small natural body of standing fresh water filling a surface depression, usually smaller than a lake.
precipitation - Water falling, in a liquid or solid state, from the atmosphere to a land or water surface.
R
rain - Water falling to earth in drops that have been condensed from moisture in the atmosphere.
receiving waters - A river, ocean, stream, or other watercourse into which wastewater or treated effluent is discharged.
recharge - The processes involved in the addition of water to the zone of saturation; also the amount of water added.
recyclable - Refers to such products as paper, glass, plastic, used oil, and metals that can be reprocessed instead of being disposed of as waste.
renewable resource - Natural resource (e.g., tree biomass, fresh water, fish) whose supply can essentially never be exhausted, usually because it is continuously produced.
reservoir - A pond, lake, or basin (natural or artificial) that stores, regulates, or controls water.
resource - A person, thing, or action needed for living or to improve the quality of life.
river - A natural stream of water of substantial volume.
river basin - A term used to designate the area drained by a river and its tributaries.
runoff - The amount of precipitation appearing in surface streams, rivers, and lakes; defined as the depth to which a drainage area would be covered if all of the runoff for a given period of time were uniformly distributed over it.
S
saltwater intrusion - The invasion of fresh surface water or groundwater by saltwater.
sanitary sewers - Underground pipes that carry off only domestic or industrial waste, not storm water.
sediment - Fragmented organic or inorganic material derived from the weathering of soil, alluvial, and rock materials; removed by erosion and transported by water, wind, ice, and gravity.
sedimentation - The deposition of sediment from a state of suspension in water or air.
seiche - A periodic oscillation, or standing wave, in an enclosed water body the physical dimensions of which determine how frequently the water level changes.
septic tank - Tank used to hold domestic wastes when a sewer line is not available to carry them to a treatment plant; part of a rural on-site sewage treatment system.
sewage - The waste and wastewater produced by residential and commercial establishments and discharged into sewers.
sewage system - Pipelines or conduits, pumping stations, force mains, and all other structures, devices, and facilities used for collecting or conducting wastes to a point for treatment or disposal.
sewer - A channel or conduit that carries wastewater and storm water runoff from the source to a treatment plant or receiving stream.
sewerage - The entire system of sewage collection, treatment, and disposal.
silt - Fine particles of sand or rock that can be picked up by the air or water and deposited as sediment.
sludge - A semi-solid residue from any of a number of air or water treatment processes.
solvent - Substances (usually liquid) capable of dissolving or dispersing one or more other substances.
spoils - Dirt or rock that has been removed from its original location, destroying the composition of the soil in the process, as with strip-mining or dredging.
spring - An area where groundwater flows naturally onto the land surface.
storm sewer - A system of pipes (separate from sanitary sewers) that carry only water runoff from building and land surfaces.
stream - Any body of running water moving under gravity flow through clearly defined natural channels to progressively lower levels.
streamflow - The discharge that occurs in a natural channel. Although the term "discharge" can be applied to the flow of a canal, the word "streamflow" uniquely describes the discharge in a surface stream. The term "streamflow" is more general than the term "runoff", as streamflow may be applied to discharge whether or not it is affected by diversion or regulation.
surface water - All water naturally open to the atmosphere (rivers, lakes, reservoirs, streams, impoundments, seas, estuaries, etc.); also refers to springs, wells, or other collectors that are directly influenced by surface water.
suspended solids (SS) - Defined in waste management, these are small particles of solid pollutants that resist separation by conventional methods. Suspended solids (along with biological oxygen demand) are a measurement of water quality and an indicator of treatment plant efficiency.
sustainable development - Development that ensures that the use of resources and the environment today does not restrict their use by future generations.
swamp - A type of wetland that is dominated by woody vegetation and does not accumulate appreciable peat deposits. Swamps may be fresh water or saltwater and tidal or nontidal.
T
temperature - The degree of hotness or coldness.
thermal pollution - The impairment of water quality through temperature increase; usually occurs as a result of industrial cooling water discharges.
toxic - Harmful to living organisms.
transpiration - The process by which water absorbed by plants, usually through the roots, is evaporated into the atmosphere from the plant surface, principally from the leaves.
tributary - A stream that contributes its water to another stream or body of water.
tsunami - A Japanese term that has been adopted to describe a large seismically generated sea wave capable of considerable destruction in certain coastal areas, especially where sub-marine earthquakes occur.
turbidity - Cloudiness caused by the presence of suspended solids in water; an indicator of water quality.
U
underground storage tank - A tank located all or partially underground that is designed to hold gasoline or other petroleum products or chemical solutions.
urban runoff - Storm water from city streets and adjacent domestic or commercial properties that may carry pollutants of various kinds into the sewer systems and/or receiving waters.
V
vapour - The gaseous phase of substances that are liquid or solid at atmospheric temperature and pressure, e.g., steam.
W
waste disposal system - A system for the disposing of wastes, either by surface or underground methods; includes sewer systems, treatment works, and disposal wells.
wastewater - Water that carries wastes from homes, businesses, and industries; a mixture of water and dissolved or suspended solids.
wastewater treatment plant - A facility containing a series of tanks, screens, filters, and other processes by which pollutants are removed from water.
water (H2O) - An odourless, tasteless, colourless liquid formed by a combination of hydrogen and oxygen; forms streams, lakes, and seas, and is a major constituent of all living matter.
water conservation - The care, preservation, protection, and wise use of water.
water contamination - Impairment of water quality to a degree that reduces the usability of the water for ordinary purposes or creates a hazard to public health through poisoning or the spread of diseases.
water management -The study, planning, monitoring, and application of quantitative and qualitative control and development techniques for long-term, multiple use of the diverse forms of water resources.
water pollution - Industrial and institutional wastes and other harmful or objectionable material in sufficient quantities to result in a measurable degradation of the water quality.
water quality - A term used to describe the chemical, physical, and biological characteristics of water with respect to its suitability for a particular use.
water quality guidelines - Specific levels of water quality that, if reached, are expected to render a body of water suitable for its designated use. The criteria are based on specific levels of pollutants that would make the water harmful if used for drinking, swimming, farming, fish production, or industrial processes.
water supply system - The collection, treatment, storage, and distribution of potable water from source to consumer.
water table - The top of the zone of saturation.
watershed - The land area that drains into a stream.
well - A pit, hole, or shaft sunk into the earth to tap an underground source of water.
wet deposition - See acid rain.
wetlands - Lands where water saturation is the dominant factor determining the nature of soil development and the types of plant and animal communities living in the surrounding environment. Other common names for wetlands are bogs, ponds, estuaries, and marshes.
withdrawal use - The act of removing water from surface water or groundwater sources in order to use it.
Z
zooplankton - Tiny aquatic animals eaten by fish.
zone of saturation - A subsurface zone in which all the pores or the material are filled with groundwater under pressure greater than atmospheric pressure.
Sources:
· Durrenberger, Robert W. Dictionary of the Environmental Sciences. Palo Alta, Ca.: National Press Books, 1973.
· Government of Canada. "Glossary of selected terms." The State of Canada's Environment. Ottawa, 1991.
· North Dakota State Water Commission. Water words: a glossary of water-related terms. Bismark, 1988.
· Parker, Sybil P. (Ed). McGraw-Hill Dictionary of Scientific and Technical Terms. 3rd ed. New York: McGraw-Hill, 1984.
· UNESCO; World Meteorological Organization. International Glossary of Hydrology. Geneva, Switzerland, 1974.
· US Environmental Protection Agency. Glossary of Environmental Terms and Acronym List. Washington, D.C., 1989.
Whittow, John. The Penguin Dictionary of Physical Geography. Markham: Penguin Books
276] largest freshwater lake in the world
Superior, Lake, largest freshwater lake in the world, 31,820 sq mi (82,414 sq km), 350 mi (563 km) long and 160 mi (257 km) at its greatest width, bordered on the W by NE Minnesota, on the N and E by Ontario, Canada, and on the S by NW Michigan and NW Wisconsin; largest, highest, and deepest of the Great Lakes, having a surface elevation of 602 ft (183 m) and a maximum depth of 1,302 ft (397 m). Lake Superior drains into Lake Huron through the St. Marys River and receives the waters of many short, swift-flowing streams including the Nipigon, Kaministikwia, St. Louis, and Pigeon rivers. The largest islands are Isle Royale, Isle St. Ignace, and Simpson and Michipicoten islands. The shoreline is irregular (with many large bays, inlets, and peninsulas) and in places is high and rocky. The waters of Lake Superior are generally purer than those of the lower lakes and are minimally polluted; a U.S.-Canadian pact (1972) was established to prevent pollution and to maintain and improve the water's quality. Commercial and sport fishing are important; and tourism is popular in the lake area. Lake Superior is part of the Great Lakes–St. Lawrence Seaway system, and it is reached by oceangoing and lake vessels through the Sault Sainte Marie Canals, which bypass rapids in the St. Marys River. The principal cargoes are grain, flour, and iron ore. The lake does not freeze completely, but ice impedes navigation from mid-December to the end of March at the lake's outlet and from early December to the end of April in harbors on the south shore. Fog and rough water are hazards. The chief Canadian cities on the lake are Michipicoten and Thunder Bay. The principal cities on the U.S. shore are Marquette, Superior, Ashland, and Duluth. Recreational facilities are found on Isle Royale (part of a U.S. national park), in Pukaskwa National Park (Ontario), and at state and provincial parks on the lake's shores and islands; the U.S. Apostle Islands and Pictured Rocks national lakeshores are there. Étienne Brulé, the French explorer, probably visited the lake in 1616; Pierre Radisson and the sieur des Groseilliers explored it in 1659–60; Father Allouez established (1665) a mission near Ashland; and the sieur Duluth visited the lake in 1678–79.
See bibliography by Water Resources Scientific Information Center (1972).
277] Glossary of Groundwater Terms
The following terms appear frequently in groundwater discussions:
Alluvium sediments consisting of silt, sand, clay, and gravel in varying proportions that are deposited by flowing water in marshes or valleys
Aquifer a saturated geologic formation (rock or sediment) capable of storing, transmitting and yielding reasonable amounts of groundwater to wells and springs
Artesian Aquifer See Confined Aquifer below.
Artesian Well a vertical bore hole in which a pipe-like structure is inserted into the ground so that it withdraws water from a confined aquifer (artesian aquifer)
Attenuation the soil's ability to lessen the amount of, or reduce the severity of groundwater contamination; "during attenuation, the soil holds essential plant nutrients for uptake by agronomic crops, immobilizes metals that might be contained in municipal sewage sludge, or removes bacteria contained in animal or human wastes. 18"
Baseflow the sustained flow (amount of water) in a stream that comes from groundwater discharge or seepage. Groundwater flows underground until the water table intersects the land surface and the flowing water becomes surface water in the form of springs, streams/rivers, lakes and wetlands. Baseflow is the continual contribution of groundwater to rivers and is important source of flow between rainstorms. Groundwater continues to discharge as baseflow because of the new recharge of rainwater in the landscape.
Bedrock solid or fractured rock usually underlying unconsolidated geologic materials; bedrock may be exposed at the land surface
Capillary Fringe saturated zone immediately above the water table where saturation is maintain by capillary tension exerted by soil pores
Condensation the process by which water or other liquids change from gas vapor to a liquid; process that occurs when water droplets form on surfaces or around the nuclei of a particle
Cone of Depression the zone (around a well in an unconfined aquifer) that is normally saturated, but becomes unsaturated as a well is pumped; an area where the water table dips down forming a "V" or cone shape due to a pumping well
Confined Aquifer (artesian aquifer) an aquifer holding water under pressure by a layer above it that does not allow water to pass through. Due to pressure, the water level of a well in a confined aquifer will rise above the top of the aquifer.
Confining Layer(aquitard or aquifuge) geologic material with little or no permeability or hydraulic conductivity. Water does not pass through this layer or the rate of movement is extremely slow.
Contaminant (pollutant) any substance that makes water unfit for a given use
Cubic Feet per Second (cfs) the volume of water in cubic feet (one-foot cube) that passes a given point in one second of time; USGS uses this measurement in reporting streamflow values
Discharge Area an area where groundwater emerges at the surface; an area where upward pressure or hydraulic head moves groundwater towards the surface to escape as a spring, seep, or baseflow of a stream
Drainage Basin the land area from which surface runoff drains into a stream or lake
Evaporation the process by which water or other liquids change from liquids to a gas vapor; evaporation can return infiltrated water to the atmosphere from upper soil layers before it reaches groundwater or surface water, and occur from leaf surfaces (interception), water bodies (lakes, streams, wetlands, oceans), small puddled depressions in the landscape.
Evapotranspiration the sum of evaporation plus transpiration
Feet per Second (ft/sec) the distance in feet that an object or water moves downstream in one second of time; a small twig floats downstream at about 1-2 ft/sec
Filtering the soil's ability to attenuate substances which includes retaining chemicals or dissolved substances on the soil particle surface, transforming chemicals through microbial biological processing, retarding movement, as well as capturing solid particles.
Flow System groundwater flow from the recharge area to a discharge area; three levels of regional, intermediate, and local. In a regional flow system, the recharge area is at the basin or watershed divide and the discharge area is at a river in the valley bottom. In a local flow system, the recharge area is at a topographical high spot and the discharge area is at a nearby topographical low spot.
Geology the study of science dealing with the origin, history, materials and structure of the earth, together with the forces and process operating to produce change within and on the earth
Glacial Drift sediment transported or deposited by glaciers or the water melting from a glacier
Glacial Outwash well-sorted sand, or sand and gravel deposited by water melting from a glacier
Groundwater the water below the water table contained in void spaces (pore spaces between rock and soil particles, or bedrock fractures)
Groundwater Basin the underground area from which groundwater drains. The basins could be separated by geologic or hydrologic boundaries.
Groundwater Divide the boundary between two adjacent groundwater basins, which is represented by a high point in the water table
Hydraulic Conductivity the term used to describe the permeability of water through a medium; a controlling factor on the rate at which water can move through a permeable medium
Hydraulic Head(head) the energy that causes groundwater to flow; the total mechanical energy per unit weight; the sum of the elevation head and the pressure head
Hydrogeology the study of the interrelationships of geologic materials and processes with water, especially groundwater
Hydrology the study of the occurrence, distribution, and chemistry of all waters of the earth
Impermeable not allowing water to pass through
Infiltration the process of water moving from the ground surface vertically downward into the soil
Interception Loss precipitation that is intercepted by trees, vegetation, and/or buildings and evaporates quickly back into the atmosphere before reaching the ground.
Interflow (subsurface stormflow) water that travels laterally or horizontally through the zone of aeration (vadose zone) during or immediately after a precipitation event and discharges into a stream or other body of water
Leachate a liquid formed by water percolating through soil or soluble waste as in a landfill
Leaching the natural process by which water transports salts and other soluble materials through the soil
Maximum Contaminant Level (MCL) the highest concentration of a substance permissible in public drinking water supply as determined by the EPA (Environmental Protection Agency)
Micrograms per Liter (ug/l) a measure of the amount of dissolved solids in a solution in terms of micrograms of solid per liter of solution; Equivalent to part per billion in water or 1ug/l=1ppb
Milligrams per Liter (mg/l) a measure of the amount of dissolved solids in a solution in terms of milligrams of solid per liter of solution; Equivalent to part per million in water or 1mg/l=1ppm
Monitoring Well a non-pumping well, generally of small diameter, that is used to measure the elevation of a water table or water quality. A piezometer is one type of monitoring well.
Moraine an accumulation of earth and stones carried by a glacier and usually deposited into a high point like a ridge
Municipal Well (public or community well) a pumping well that serves water to more than 25 people for at least 60 days of the year
Nitrate (NO3) a chemical formed when nitrogen from ammonia (NH3), ammonium (NH4) and other nitrogen sources combines with oxygenated water
Non-point Source Pollution pollution from dispersed sources like agricultural activities, urban runoff, and atmospheric deposition
Part per Billion (ppb) a measure of the amount of dissolved solids in a solution in terms of a ratio between the number of parts of solids to a billion parts of total volume; Equivalent to microgram per liter in water or 1ppb=1 ug/l
Part per Million (ppm) a measure of the amount of dissolved solids in a solution in terms of a ratio between the number of parts of solids to a million parts of total volume; Equivalent to milligram per liter in water or 1ppm=1 mg/l
Perched Aquifer a saturated zone with in the zone of aeration that overlies a confining layer; a perched aquifer is above the main water table.
Percolation the actual movement of subsurface water either horizontally or vertically; lateral movement of water in the soil subsurface toward nearby surface drainage feature (e.g. stream) or vertical movement through the soil to groundwater zone.
Permeability the property or capacity of a soil or rock for transmitting a fluid, usually water; the rate at which a fluid can move through a medium
Pesticides chemicals including insecticides, fungicides, and herbicides that are used to kill living organisms
Piezometer a type of monitoring well that is open only at the top and bottom of its casing
Plume an underground pattern of contaminant concentrations created by the movement of groundwater beneath a contaminant source. Contaminants spread mostly laterally in the direction of groundwater movement. The spill/source site is the highest concentration, and the concentration decreases away from the source.
Point Source Pollution pollution from distinct sources, such as industrial discharge pipes, underground storage tanks, septic systems, or spills
Porosity the ratio of the volume of void or air spaces in a rock or sediment to the total volume of the rock or sediment
Potable water safe for drinking
Potentiometric Surface an imaginary surface that represents the level to which water rises in wells in a confined aquifer; (similar to the water table of an unconfined aquifer)
Precipitation deposition of rain, snow, sleet, dew, frost, fog, or hail
Private Well a pumping well that serves one home or is maintained by a private owner
Quantity of groundwater the amount of groundwater stored in an aquifer that is available for use
Recharge Area an area in which water infiltrates and moves downward into the zone of saturation of an aquifer; area that replenishes groundwater
Runoff-Direct the sum of surface runoff and interflow
Runoff-Surface (overland flow) precipitation that cannot be absorbed by the soil because the soil is already saturated with water (saturation excess overland flow); precipitation that exceeds infiltration; the portion of rain, snow melt, irrigation water, or other water that moves across the land surface and enters a wetland, stream, or other body of water (overland flow). Overland flow usually occurs in urban settings (pavement, roofs, etc.) or where the soils are very fine textured or heavily compacted.
Runoff-Total includes the sum of surface runoff (overland flow), baseflow, and interflow (subsurface stormflow) that moves across or through the land and enters a stream or other body of water.
Septic System-conventional (private onsite wastewater treatment system [POWTS]) used to treat household sewage and wastewater by allowing the solids to decompose and settle in a tank, then letting the liquid be absorbed by the soil in a drainage field
Spring a natural discharge of groundwater at the land's surface
Stemflow water that is intercepted by vegetation and then runs down plant stems or tree trunks to the soil surface
Surface Water water found in ponds, lakes, streams, rivers, and inland seas
Throughfall water that is intercepted by vegetation and then drips off it to reach the soil surface
Till glacier deposits composed primarily of unsorted sand, silt, clay, and boulders laid down directly by the melting ice
Topographic Divide a high point in the land surface that provides a boundary between adjacent watersheds or basins
Topography the contour of the land surface; the arrangement of the land surface including its relief and the position of its natural and man-made features
Toxin a poisonous compound that causes certain diseases or health problems
Transpiration the process by which plants take up water through their roots and then give off water vapor through their leaves (open stomata)
Unconfined Aquifer (water table aquifer) an aquifer with continuous layers of permeable soil and rock that extends from the land surface to the base of the aquifer. The water table forms the upper boundary of the aquifer.
Watershed the land area from which surface water and groundwater drains into a stream system; the area of land that generates total runoff (surface flow, interflow, and baseflow) for a particular stream system
Water Cycle (hydrologic cycle) the continuous circulation of water from the atmosphere to the earth and back to the atmosphere including condensation, precipitation, runoff, groundwater, evaporation, and transpiration
Water Table the water surface in an unconfined aquifer; the level below which the pore spaces in the soil or rock are saturated with water; the upper surface of the zone of saturation
Water Table Contour a line in a groundwater map that connects points of equal groundwater elevation
Well a vertical bore hole in which a pipe-like structure is inserted into the ground in order to discharge (pump) water from an aquifer
Zone of Aeration (vadose zone or unsaturated zone) the zone between the land surface and the water table in which the pore spaces between soil and rock particles contain water, air, and/or other gases
Zone of Saturation (saturated zone) the zone in which the pore spaces between soil and rock particles are completely filled with water. The water table is the top of the zone of saturation
278] Drinking Water Contaminants
Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk. EPA sets standards for approximately 90 contaminants in drinking water. EPA's standards, along with each contaminant's likely source and health effects, are available at www.epa.gov/safewater/mcl.html. More detailed information on specific contaminants is available below:
Microbes ~ Radionuclides ~ Inorganics ~ Volatile Organics ~ Synthetic
Organics ~ Disinfectants ~ Disinfection Byproducts ~ MTBE ~ Health Advisories
Microbes
Coliform bacteria
are common in the environment and are generally not harmful. However, the presence of these bacteria in drinking water is usually a result of a problem with the treatment system or the pipes which distribute water, and indicates that the water may be contaminated with germs that can cause disease.
Fecal Coliform and E coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes. Microbes in these wastes can cause short-term effects, such as diarrhea, cramps, nausea, headaches, or other symptoms.
Turbidity has no health effects. However, turbidity can interfere with disinfection and provide a medium for microbial growth. Turbidity may indicate the presence of disease causing organisms. These organisms include bacteria, viruses, and parasites that can cause symptoms such as nausea, cramps, diarrhea, and associated headaches.
Cryptosporidium is a parasite that enters lakes and rivers through sewage and animal waste. It causes cryptosporidiosis, a mild gastrointestinal disease. However, the disease can be severe or fatal for people with severely weakened immune systems. EPA and CDC have prepared advice for those with severely compromised immune systems who are concerned about Cryptosporidium.
Giardia lamblia is a parasite that enters lakes and rivers through sewage and animal waste. It causes gastrointestinal illness (e.g. diarrhea, vomiting, cramps).
Radionuclides
Alpha emitters.
Certain minerals are radioactive and may emit a form of radiation known as alpha radiation. Some people who drink water containing alpha emitters in excess of EPA's standard over many years may have an increased risk of getting cancer.
Beta/photon emitters. Certain minerals are radioactive and may emit forms of radiation known as photons and beta radiation. Some people who drink water containing beta and photon emitters in excess of EPA's standard over many years may have an increased risk of getting cancer.
Combined Radium 226/228. Some people who drink water containing radium 226 or 228 in excess of EPA's standard over many years may have an increased risk of getting cancer.
Radon gas can dissolve and accumulate in underground water sources, such as wells, and in the air in your home. Breathing radon can cause lung cancer. Drinking water containing radon presents a risk of developing cancer. Radon in air is more dangerous than radon in water.
Inorganic Contaminants
Antimony Asbestos Barium Beryllium Cadmium Chromium Copper Cyanide Mercury Nitrate Nitrite Selenium Thallium
Arsenic. Some people who drink water containing arsenic in excess of EPA's standard over many years could experience skin damage or problems with their circulatory system, and may have an increased risk of getting cancer.
Fluoride. Many communities add fluoride to their drinking water to promote dental health. Each community makes its own decision about whether or not to add fluoride. EPA has set an enforceable drinking water standard for fluoride of 4 mg/L (some people who drink water containing fluoride in excess of this level over many years could get bone disease, including pain and tenderness of the bones). EPA has also set a secondary fluoride standard of 2 mg/L to protect against dental fluorosis. Dental fluorosis, in its moderate or severe forms, may result in a brown staining and/or pitting of the permanent teeth. This problem occurs only in developing teeth, before they erupt from the gums. Children under nine should not drink water that has more than 2 mg/L of fluoride.
Lead typically leaches into water from plumbing in older buildings. Lead pipes and plumbing fittings have been banned since August 1998. Children and pregnant women are most susceptible to lead health risks. For advice on avoiding lead, see EPA's lead in your drinking water fact sheet.
Synthetic Organic Contaminants,
including pesticides & herbicides
2,4-D 2,4,5-TP (Silvex) Acrylamide Alachlor Atrazine Benzoapyrene Carbofuran Chlordane Dalapon Di 2-ethylhexyl adipate Di 2-ethylhexyl phthalate Dibromochloropropane Dinoseb Dioxin (2,3,7,8-TCDD) Diquat Endothall Endrin Epichlorohydrin Ethylene dibromide Glyphosate Heptachlor Heptachlor epoxide Hexachlorobenzene Hexachlorocyclopentadiene Lindane Methoxychlor Oxamyl [Vydate] PCBs [Polychlorinated biphenyls] Pentachlorophenol Picloram Simazine Toxaphene
Volatile Organic Contaminants
Benzene Carbon Tetrachloride Chlorobenzene o-Dichlorobenzene p-Dichlorobenzene 1,1-Dichloroethylene cis-1,2-Dichloroethylene trans-1,2-Dicholoroethylene Dichloromethane 1,2-Dichloroethane 1,2-Dichloropropane Ethylbenzene Styrene Tetrachloroethylene 1,2,4-Trichlorobenzene 1,1,1,-Trichloroethane 1,1,2-Trichloroethane Trichloroethylene Toluene Vinyl Chloride Xylenes
Technical fact sheets on Volatile Organic Contaminants
Disinfectants
Many water suppliers add a disinfectant to drinking water to kill germs such as giardia and
e coli. Especially after heavy rainstorms, your water system may add more disinfectant to guarantee that these germs are killed.
Chlorine. Some people who use drinking water containing chlorine well in excess of EPA's standard could experience irritating effects to their eyes and nose. Some people who drink water containing chlorine well in excess of EPA's standard could experience stomach discomfort.
Chloramine. Some people who use drinking water containing chloramines well in excess of EPA's standard could experience irritating effects to their eyes and nose. Some people who drink water containing chloramines well in excess of EPA's standard could experience stomach discomfort or anemia.
Chlorine Dioxide. Some infants and young children who drink water containing chlorine dioxide in excess of EPA's standard could experience nervous system effects. Similar effects may occur in fetuses of pregnant women who drink water containing chlorine dioxide in excess of EPA's standard. Some people may experience anemia.
Disinfection Byproducts
Disinfection byproducts form when disinfectants added to drinking water to kill germs react with naturally-occuring organic matter in water.
Total Trihalomethanes. Some people who drink water containing trihalomethanes in excess of EPA's standard over many years may experience problems with their liver, kidneys, or central nervous systems, and may have an increased risk of getting cancer.
Haloacetic Acids. Some people who drink water containing haloacetic acids in excess of EPA's standard over many years may have an increased risk of getting cancer.
Bromate. Some people who drink water containing bromate in excess of EPA's standard over many years may have an increased risk of getting cancer.
Chlorite. Some infants and young children who drink water containing chlorite in excess of EPA's standard could experience nervous system effects. Similar effects may occur in fetuses of pregnant women who drink water containing chlorite in excess of EPA's standard. Some people may experience anemia.
MTBE is a fuel additive, commonly used in the United States to reduce carbon monoxide and ozone levels caused by auto emissions. Due to its widespread use, reports of MTBE detections in the nation's ground and surface water supplies are increasing. The Office of Water and other EPA offices are working with a panel of leading experts to focus on issues posed by the continued use of MTBE and other oxygenates in gasoline. EPA is currently studying the implications of setting a drinking water standard for MTBE.
Health advisories provide additional information on certain contaminants. Health advisories are guidance values based on health effects other than cancer. These values are set for different durations of exposure (e.g., one-day, ten-day, longer-term, and lifetime).
What is Antimony and how is it used?
Antimony is a metal found in natural deposits as ores containing other elements. The most widely used antimony compound is antimony trioxide, used as a flame retardant. It is also found in batteries, pigments, and ceramics/glass.
What is Asbestos and how is it used?
Asbestos is a fibrous mineral occurring in natural deposits. Because asbestos fibers are resistant to heat and most chemicals, they have been mined for use in over 3,000 different products, including roofing materials, brake pads, and cement pipe often used in distributing water to communities.
What is Barium and how is it used?
Barium is a lustrous, machinable metal which exists in nature only in ores containing mixtures of elements. It is used in making a wide variety of electronic components, in metal alloys, bleaches, dyes, fireworks, ceramics and glass. In particular, it is used in well drilling operations where it is directly released into the ground.
What is Beryllium and how is it used?
Beryllium is a metal found in natural deposits as ores containing other elements, and in some precious stones such as emeralds and aquamarine. The greatest use of beryllium is in making metal alloys for nuclear reactors and the aerospace industry
What is Cadmium and how is it used?
Cadmium is a metal found in natural deposits as ores containing other elements. The greatest use of cadmium is primarily for metal plating and coating operations, including transportation equipment, machinery and baking enamels, photography, television phosphors. It is also used in nickel-cadmium and solar batteries and in pigments.
What is Chromium and how is it used?
Chromium is a metal found in natural deposits as ores containing other elements. The greatest use of chromium is in metal alloys such as stainless steel; protective coatings on metal; magnetic tapes; and pigments for paints, cement, paper, rubber, composition floor covering and other materials. Its soluble forms are used in wood preservatives
What is Copper and how is it used?
Copper is a metal found in natural deposits as ores containing other elements. It is widely used in household plumbing materials.
What is Cyanide and how is it used?
Cyanide is a carbon-nitrogen chemical unit which combines with many organic and inorganic compounds. The most commonly used form, hydrogen cyanide, is mainly used to make the compounds needed to make nylon and other synthetic fibers and resins. Other cyanides are used as herbicides.
What is Mercury and how is it used?
Mercury is a liquid metal found in natural deposits as ores containing other elements. Electrical products such as dry-cell batteries, fluorescent light bulbs, switches, and other control equipment account for 50% of mercury used.
What are Nitrates/Nitrites and how are they used?
Nitrates and nitrites are nitrogen-oxygen chemical units which combines with various organic and inorganic compounds. Once taken into the body, nitrates are converted into nitrites. The greatest use of nitrates is as a fertilizer.
What is Selenium and how is it used?
Selenium is a metal found in natural deposits as ores containing other elements. The greatest use of selenium compounds is in electronic and photocopier components, but they are also widely used in glass, pigments, rubber, metal alloys, textiles, petroleum, medical therapeutic agents, and photographic emulsions.
What is Thallium and how is it used?
Thallium is a metal found in natural deposits as ores containing other elements. The greatest use of thallium is in specialized electronic research equipment
278] Is water related to climate?
Water and climate are intimately related. It is obvious, from a water resource perspective, how the climate of a region to a large extent determines the water supply in that region based on the precipitation available and on the evaporation loss. Perhaps less obvious is the role of water in climate. Large water bodies, such as the oceans and the Great Lakes, have a moderating effect on the local climate because they act as a large source and sink for heat. Regions near these water bodies generally have milder winters and cooler summers than would be the case if the nearby water body did not exist.
Water has a basic role in the climate system through the hydrologic cycle. The evaporation of water into the atmosphere requires an enormous amount of energy, which ultimately comes from the sun. The sun's heat is trapped in the earth's atmosphere by greenhouse gases, the most plentiful of which by far is water vapour. When water vapour in the atmosphere condenses to precipitation, this energy is released into the atmosphere. Fresh water can mediate climate change to some degree because it is
stored on the landscape as lakes, snow covers, glaciers, wetlands, and rivers, and is a store of latent energy. Thus water acts as an energy transfer and storage medium for the climate system
The water cycle is also a key process upon which other cycles operate. For example one needs to properly understand the water cycle in order to address many of the chemical cycles in the atmosphere.
Most scientists are predicting extensive climate change. How would this affect water resources?
We have all experienced the natural variability in climate from time to time in the form of cool summers, warm winters, and droughts. It is now believed that changes to the atmospheric composition may result in unprecedented changes in the global climate within the next 100 years. The increasing concentrations of "greenhouse" gases, such as carbon dioxide (from the burning of coal, oil, and gas for industry and energy production, and from large-scale deforestation) and methane (from rice paddies, wetlands, and livestock), trap heat near the earth's surface. As a result, the global mean temperature is expected to increase, with resulting changes in climate being more pronounced in the northern latitudes, which include much of Canada.
Because of the intimate relationship between climate and the hydrologic cycle, changes in the climatic regimes would directly affect the average annual water flow, its annual variability, and its seasonal distribution. For example, greater climatic variability would mean changing the frequency of extreme weather events and increasing the incidences of dry and wet year sequences. Water supplies would become more uncertain as a result of this combined with increased summer evapotranspiration, reduced snowpacks, and unknown water use responses to climate change. Current design criteria for hydrologically related infrastructures such as dams, culverts, urban sewage capacities, wharves, channels, docks, and dykes, as well as for zoning, flow allocation, dam management, and flood damage reduction efforts, may prove to be inadequate under future climatic conditions.
The effects of climate change on the quality of water would modify the stress on aquatic life and cause new cleanup problems. For example, unusually low water levels – which can impair navigation, stimulate the growth of noxious nearshore weeds, and increase the probability of summer fish kills due to anoxia (lack of oxygen) – would require increased dredging activities, thus harming bottom-dwelling organisms and contaminating surrounding waters. Further, low flows will decrease the dilution of effluents resulting in increased contamination levels in receiving waters.
279] What is a drought?
A drought is a sustained and regionally extensive occurrence of appreciably below-average natural water availability in the form of precipitation, streamflow, or groundwater. Droughts are natural events of varying duration that have occurred throughout history and they are part of the cyclical fluctuations of our planet's climate system
280] What causes floods?
Flooding is almost always a natural occurrence; an exception would be flooding due to the collapse of a dam. There are many conditions and variables that determine whether a lake or river overtops its banks or an ocean rises along its shores. The most common causes of flooding in Canada are water backing up behind ice jams and the rapid melting of heavy winter snow cover, particularly when accompanied by rainfall. Heavy rainfall by itself can also cause floods. On large lakes, severe storms can result in strong surges when sustained high winds from one direction push the water level up at one end of the lake. Flooding is worse if high tides occur at the same time.
Certain conditions affect only specific regions in Canada. For example, under-sea disturbances such as volcanic eruptions or earthquakes may result in catastrophic waves called "tsunamis" in the ocean coastal regions. In the glaciated areas of Canada, lakes dammed by glaciers (extensive bodies of land ice) may drain suddenly, resulting in glacier-outburst floods. These floods are called "jökulhlaups" and can be devastating to the local ecosystem as they can cause flood levels of up to 100 times greater than those of normal rain or snowmelt floods.
How does groundwater become contaminated?
Groundwater becomes contaminated when anthropogenic, or people-created, substances are dissolved or mixed in waters recharging the aquifer. Examples of this are road salt, petroleum products leaking from underground storage tanks, nitrates from the overuse of chemical fertilizers or manure on farmland, excessive applications of chemical pesticides, leaching of fluids from landfills and dumpsites, and accidental spills.
Contamination also results from an overabundance of naturally occurring iron, sulphides, manganese, and substances such as arsenic. Excess iron and manganese are the most common natural contaminants. Another form of contamination results from the radioactive decay of uranium in bedrock, which creates the radioactive gas radon. Methane and other gases sometimes cause problems. Seawater can also seep into groundwater and is a common problem in coastal areas. It is referred to as "saltwater intrusion".
Compared with surface water, is groundwater safe for human consumption?
Groundwater is generally safer than surface water for drinking because of the filtration and natural purification processes that take place in the ground. These processes become ineffective, however, when sewage, fertilizers, toxic chemicals, and road salt, seep into the ground.
Household, commercial, and industrial wastes that end up in dumps, waste lagoons, or septic systems can pollute groundwater. Acid rain also threatens to recharge aquifers with contaminated water.
Generally, groundwater is not as easily contaminated as surface water, but once it is contaminated, it is much more difficult to clean up because of its relative inaccessibility.
281] What is an aquatic ecosystem?
An aquatic ecosystem is a group of interacting organisms dependent on one another and their water environment for nutrients (e.g., nitrogen and phosphorus) and shelter. Familiar examples are lakes and rivers, but aquatic ecosystems also include areas such as floodplains and wetlands, which are flooded with water for all or only parts of the year. Seemingly inhospitable aquatic ecosystems can sustain life. Thermal springs, for instance, support algae and some insect species at water temperatures near the boiling point; tiny worms live year-round on the Yukon ice fields; and some highly polluted waters can support large populations of bacteria.
Even a drop of water is an aquatic ecosystem, since it contains or can support living organisms. In fact, ecologists often study drops of water – taken from lakes and rivers – in the lab to understand how these larger aquatic ecosystems work.
282] What is the range of organisms found in aquatic ecosystems?
Aquatic ecosystems usually contain a wide variety of life forms including bacteria, fungi, and protozoans; bottom-dwelling organisms such as insect larvae, snails, and worms; free-floating microscopic plants and animals known as plankton; large plants such as cattails, bulrushes, grasses, and reeds; and also fish, amphibians, reptiles, and birds. Viruses are also a significant part of the microbial ecology in natural waters and have recently been shown to play an important role in the nutrient and energy cycles.
The assemblages of these organisms vary from one ecosystem to another because the habitat conditions unique to each type of ecosystem tend to affect species distributions. For example, many rivers are relatively oxygen-rich and fast-flowing compared to lakes. The species adapted to these particular river conditions are rare or absent in the still waters of lakes and ponds.
283] How does an ecosystem work?
Energy from the sun is the driving force of an ecosystem. This light energy is captured by primary producers (mainly green plants and algae) and converted by a process called photosynthesis into chemical energy such as carbohydrates.
The chemical energy is then used by the plants to perform a variety of functions including the production of plant parts such as leaves, stems, and flowers. The raw materials used for this purpose are nutrients (e.g., nitrogen, phosphorus, oxygen, and calcium): substances necessary for the growth of all plants and animals.
Animals are incapable of photosynthesis. They therefore eat either plants, other animals, or dead tissue to obtain their energy and required nutrients. In ecosystems, the transfer of energy and nutrients from plants to animals occurs along pathways called food chains. The first link in a food chain consists of primary producers: green plants and other organisms capable of photosynthesis.
Plant-eating organisms, known as primary consumers, are the next link in the food chain. They, in turn, are eaten by secondary consumers: carnivores (flesh eaters) or omnivores (plant and animal eaters). Decomposers such asbacteria and fungi make up the final link in the food chain. They break down dead tissues and cells, providing nutrients for a new generation of producers.
Most organisms in an ecosystem have more than one food source (e.g., fish feed on both insects and plants) and therefore belong to more than one food chain. The consequent overlapping food chains make up food webs: complex phenomena with links that are constantly changing
284] What are wetlands?
Wetlands are defined as lands saturated by surface or near surface waters for periods long enough to promote the development of hydrophytic vegetation (e.g., weeds, bulrushes, and sedges) and gleyed (poorly drained) or peaty soils.
There are five basic classes of wetlands: bogs, fens, saltwater and freshwater marshes, swamps, and shallow water.
What kinds of animals use wetlands?
Wetlands are important to species from many familiar classes of animals, as well as to less commonly known creatures.
Every drop of water contains microscopic zooplankton, which are a vital component of the food chain. The water's surface and the wetland bottom are covered with insect eggs, larvae, and nymphs. Members of the fish, amphibian, and reptile groups are all dependent on the habitat provided by wetlands. Numerous bird and mammal species make extensive use of the water and its adjacent shores. These species can be important to humans economically or as indicators of environmental health.
How do wildlife species use wetlands?
Food and shelter are the primary requirements of life. Wetlands provide these functions for many species of animals that either live permanently within the wetland or visit periodically. Almost every part of a wetland, from the bottom up, is important to wildlife in some way. Frogs bury themselves in the muddy substrate to survive the winter, and some insects use bottom debris to form a protective covering. Fish swim and feed in wetlands, often eating the eggs of insects that have been deposited in the water. Wetland vegetation provides nesting materials and support structures to several bird species and is a major source of food to mammals, even those as large as moose. Small mammals use the lush vegetation at the edge of wetlands for cover and as a source of food, and they themselves are a food source for birds of prey. Each species has adapted to using the wetland and its surrounding area in a particular way.
274]
balayogi
Dear Sh.Bala Yogi,
Just now I got a feed back from Dr.MANICKAM,a Biochemist on water. He is also of the view that water is an unique molecule needs to be probed further. He raised a question ‘ why water is basis of life why not an ester or alcohol. YOU FLOAT THE IDEA ON WATER IN YOUR NET ALSO we may get some answer.
Regards,
Smurthy
vtsmurthycbe@yahoo.co.in
Dr.V.T.Sundaramurthy, "Srivaishnavasri", 23, Maniyakarar Street, Veerakeralam, Coimbatore - 641 007, Tamil Nadu, Ph: +91 422 2473853, email: drvtsms@yahoo.co.in, Website: http://www.geocities.com/drvtsms/
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