Backgrounder...
Population and Water
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Why Cover Population and Water?
If you have ever visited Mesa Verde National Park, with its cliff-dwellings and other remnants of a once-magnificent civilization, you may have some appreciation of how vital water is to people. Mesa Verde’s inhabitants vanished sometime around 1300 A.D. Drought, according to the leading theory, was what caused this civilization’s demise, although nobody knows for sure.
Especially in water-rich parts of the United States, few Americans stop to worry about whether or how the availability of water resources is linked to the number and well-being of people. But it is. Water, almost like a paint brush filling in parts of a map, has to a large extent determined where the population of the United States has settled and grown.
Not many Americans thought much about the drought in Afghanistan that had brought hardship, dislocation, and death to millions there — until the events of September 11, 2001, drove home once more how interconnected we are to the rest of the world. The social chaos that can accompany drought and famine does touch us eventually. The desperation born of water-related famine, disease, and poverty is a prime breeding ground for terrorism and extremism. Conflict between nations over water still threatens to destabilize explosive regions like the Middle East.
Story Ideas
- If you live in an arid part of the United States, what are the limits of your local/regional water supplies? Does your area have a growth plan that takes these limits into account?
- How much of the water in your area is used for irrigation? How water-efficient are the irrigation methods in your area, and how much water is lost in transit? What are the financial incentives and disincentives for water efficiency?
- If you live in an agricultural region, find out the degree to which your local economy may depend on export of food commodities to other nations. Do water resources limit the amount of food your region can grow? Will world trends in population and water mean that other nations will increasingly depend on food imports?
Background and Context
There is only a finite amount of water available for human use at a given time. An expanding world population will need increasing amounts of water for drinking, irrigation, and industry. The worry in many countries, and various international agencies, is that people will run out of water.
The problem is not always that simple or easy to see. What matters is getting water of usable quality to the people who need it — water in the right place at the right time. Years of flooding may be followed by years of drought. It may be easier to blame the drought than to admit that the population of an area has grown beyond what its water resources will support. To be truly sustainable, a society needs to be able to survive drought.
In her book, Pillar of Sand, author Sandra Postel writes that about 40 percent of the world’s food comes from farmland that is irrigated — “and we’re betting on that share to feed a growing population.”
But irrigation can only take a hungry world so far. Ground water in many places — including the U.S. High Plains states — is being pumped for irrigation faster than rain and snow are replacing it. Moreover, long irrigation of poorly drained fields can make the soil salty and even harder to grow things in. One in five irrigated acres suffers from salt damage, according to Postel. Salt build-up forces about 1.5 million hectares of irrigated cropland out of production every year — offsetting about half of the acreage brought into production, Postel writes.
Some 31 nations, home to 508 million people, suffered from water stress or water scarcity in 2000, according to the United Nations Population Fund (UNFPA). United Nations agencies define nations with less than 1,700 cubic meters of renewable water available per person per year as “water stressed,” and those with less than 1,000 cubic meters per person per year as "water scarity." And by 2025, the U.N. predicts that 3 billion people in some 48 countries will be facing such shortages.
The problem is not merely one of how much water, but also one of how useable it is in quality. Population growth often means more irrigation — and the water that drains off of irrigated fields may be polluted with minerals, fertilizer, pesticides, or even disease organisms. The new industry that accompanies population growth may pollute not only with nutrients, but also with toxic chemicals. So growing populations not only use up water supplies, but can actually reduce the amount of safe and useable water available.
Most important is what happens to the sewage generated by a growing population and its pollution of safe drinking water for that population or people downstream. In the developing world, more than 90 percent of the sewage may be dumped into waterways untreated. The World Health Organization estimates that about 1.1 billion people have no access to clean drinking water, and that between 2.4 and 3 billion people are not served by even basic sanitation systems.
The results are often fatal. The official estimates from WHO’s Global Water Supply and Sanitation Assessment 2000 are that 3.4 million people, mostly children, die yearly from waterborne disease. Some 2.2 million, WHO says, die from diarrheal diseases (typically waterborne) such as cholera annually, most of them children in developing nations. “This is equivalent to one child dying every 15 seconds, or 20 jumbo jets crashing every day,” a WHO report notes. Other estimates have put the numbers higher, and researchers say waterborne disease is often under-reported.
The body count is not the whole story. A great many more people suffer misery or disability from other water-related diseases which are not fatal — everything from parasitic diseases like schistosomiasis, giardiasis, and malaria to fluorosis and arsenic poisoning. By some estimates, nearly half of the world’s population suffers from some kind of water-related disease.
Paradoxically, a 1991 UNFPA report noted, high death rates for children under five from waterborne disease and other causes has prompted some couples in developing nations to compensate by having even more children, to ensure that some survive.
How It Hits Home
The vital interdependence between population and water is not merely “Afghanistanism” — a term used to disparage coverage emphasizing foreign news at the expense of local news (at least before September 11, 2001). It is part of many water and population stories in the United States as well.
While the United States as a whole is blessed with far more renewable water resources than many countries around the globe — averaging about 10,000 cubic meters per person per year — the picture in a given locality may be very different.
California — specifically Los Angeles — is the obvious example.
By some accounts, Los Angeles has no business existing — at least not a county of nearly 10 million people, more than all but eight U.S. states, in a semi-arid region with scarcely more than a trickle of water to call its own. Los Angeles was able to grow during the 20th century from a small town of 100,000 to a megalopolis largely because of the work of water engineers like William Mulholland, who diverted the Owens River into the Los Angeles Aqueduct in 1913.
Southern California exists largely by importing water from elsewhere through one of the world’s most extensive systems of canals and aqueducts. The water comes from Mono Lake, the Sierra Nevadas much farther north in the state, and the Colorado River. Water engineering not only allowed explosive urban growth, but also the development of huge tracts of irrigated cropland in southern and central California.
But things are not hunky-dory. Southern California seems to have reached the limits of available water supplies. Recent droughts (e.g., the severe one from 1987 to 1992) have been devastating enough to underline this point. Yet Southern California is expected to keep growing, with the state’s population projected to double from about 30 million in 1990 to about 60 million in 2040. Additional future water needs can probably only be met by increasing efficiency or by reallocating water from irrigation to urban use. California’s water system was developed with major federal and state subsidies, as well as local cost-sharing. In retrospect, the wisdom of water policies that encourage growth beyond sustainable limits is worth questioning.
California also exemplifies the dangers that population-driven water development poses to ecosystems and the environment generally. During the 1987-92 drought, water quality worsened, populations of endangered species shrunk, and whole fish populations were eradicated as certain streams and lakes dried up entirely. Today, roughly 90 percent of the original estimated 5 million acres of wetlands in California before Europeans arrived have been drained, filled, or otherwise destroyed.
California is hardly alone. Water limits have been reached in other parts of the United States as well. The Ogallala aquifer, which underlies the great plains states of Texas, Oklahoma, Kansas, and Colorado has also been significantly depleted by groundwater “mining” — pumping ancient aquifers faster than they are replenished, if they are replenished at all. Eventually, the cost of drilling wells deeper and pumping water higher is no longer economically worthwhile. As a result, the amount of irrigated acreage in Texas has been going down by about one percent a year since 1980 — and figures are similar in other states using the Ogallala.
Another way to see the limits of water from a U.S. perspective is to look at the Colorado River. It is the vital artery that supplies water to much of the American Southwest. It has long been all used up — the real question now being how many times water can be re-used on its way downstream — with its quality degraded at every step. By the time the river reaches the Gulf of California, it has dried to an intermittent trickle.
A final example is the Pacific Northwest — not a region you might expect to be discussed here because it is one of the most water-rich in the United States. The drought that afflicted Washington, Oregon, and Idaho during 2000-2001 has eased, but it brought power shortages and factory shutdowns, as well as intensified conflict over scarce water resources — such as the dispute between farmers and salmon conservationists at the Klamath Irrigation Project at the Oregon-California border. The Northwest has extensively developed its water resources, and has come to rely on them for power and irrigation — precisely because water is so abundant. But because the region depended so heavily on water, its people became vulnerable when annual rain and snowfall fluctuated.
If history — and paleoclimatology and geology — teaches us anything, it teaches us that climate does change. It changes with random yearly variations, and with natural cycles scientists have only recently begun to understand (such as El Niño and the Pacific Decadal Oscillation). It is also likely to change when (it is no longer a matter of whether) human-caused greenhouse warming kicks in.
It is easy to miss this vulnerability to climate variations if we see the water-population story only as a matter of statistics and averages. For nations at their hydrologic limits, there may be no margin of safety. The lesson is one the United States might have learned in Somalia in the early 1990s— not merely the mass starvation caused in such countries by drought, but the social disintegration and war which were a partial byproduct, and the degree to which U.S. citizens could not escape it half a world away.
If Seattle and Portland were vulnerable to drought, how much more vulnerable will people in Bangladesh or Ethiopia be?
Players and Sources
- Population Action International, Press contacts: Kimberley Cline, (202) 557-3423, kcline@popact.org; Sally Ethelston, (202) 557-3418, sae@popact.org. “Sustaining Water: Population and the Future of Renewable Water Supplies,” by PAI, http://www.cnie.org/pop/pai/h2o-toc.html. Update at http://www.populationaction.org/resources/publications/water/water97.pdf.
- Population Reference Bureau Web site includes directory of experts. Press contact: Ellen Carnevale, (202) 939-5407, ecarnevale@prb.org, http://www.prb.org/.
- Worldwatch Institute, Pillar of Sand: Can the Irrigation Miracle Last? by Sandra Postel, published by Worldwatch Institute, http://www.worldwatch.org/pubs/ea/pos.html, Press contact: Leanne Mitchell, (202) 452-1992 ext.527, mitchell@worldwatch.org; or Richard C. Bell, (202) 452-1992 ext. 517, dbell@worldwatch.org.
- World Resources Institute Press contact: Adlai Amor, (202) 729-7736, aamor@wri.org, http://www.wri.org.
- United Nations
- Population and Environment Linkages Service (National Library for the Environment), abstracts and links to more than 14,000 books, reports, and articles, http://www.popenvironment.org.
- U.S. Geological Survey, “Estimated Use of Water in the United States in 1995,” http://water.usgs.gov/watuse/ (figures for 2000 will be at this site when available).
(This backgrounder was produced with financial support from The William and Flora Hewlett Foundation.)
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Note: Formerly published by the National Safety Council. Reprinted with permission.