METTING NATURE'S WATER NEEDS
From Chapter 8. Restoring the Earth

Lester R. Brown, Plan B 2.0: Rescuing a Planet Under Stress and a Civilization in Trouble (NY: W.W. Norton & Co., 2006).

There are many reasons for balancing water demand and supply. Failure to do so means that water tables will continue to fall, more rivers will run dry, and more lakes will disappear. If water tables are falling while energy prices are rising, irrigation water costs can rise to where farmers can no longer afford to irrigate. (Ways to raise irrigation efficiency are discussed in Chapter 9. Chapter 11 describes ways to reduce urban water waste.)

In Rivers for Life: Managing Water for People and Nature, Sandra Postel and Brian Richter cite South Africa’s 1998 National Water Act as a model for other countries. The act focuses on two broad needs. The first is satisfying basic water needs of everyone for drinking, cooking, sanitation, and other essential purposes, which the legislation describes as a non-negotiable allocation. The second is the water needed to support river ecosystem functions “in order to conserve biodiversity and secure the valuable ecosystem services they provide to society.” 38

Establishing minimal river flows so as to satisfy the specific needs of downstream aquatic ecosystems such as floodplains, river deltas, and wetlands is not necessarily easy. For example, at times a strong flow is needed to meet the freshwater needs of an estuary. At other times, the needs of spawning fish may determine the ecological water needs.

A World Conservation Union–IUCN study in Australia notes that the Mowamba aqueduct has been permanently closed after 100 years of use in order to raise the flow of the Snowy River. This initial action, which raises the river flow from 3 percent of the natural level to 6 percent, is the first in a series of steps to bring the river flow back to 28 percent of the natural level and thus to restore its natural functions. In Australia’s Murray-Darling basin, the enhanced flow of a river with releases from a storage facility in the basin helped to restore the natural wildlife population. The IUCN report noted, “the great egret bred for the first time since 1979, nine species of frog bred, as did native fish.” 39

Perhaps the best known and largest example of returning water to restore and support marine habitats occurred in California when the U.S. Congress passed legislation in 1992 that was designed to restore the overall health of the fish and wildlife habitat, including salmon runs, of the Sacramento-San Joaquin river system. Initially, as Sandra Postel reports in Pillar of Sand, Congress authorized the use of 800,000 acre-feet, nearly 1 billion cubic meters, or about 10 percent of the Central Valley Project’s yearly water supply, for this purpose. Farmers who lost part of their irrigation water challenged the law. 40

After several years of legal challenges and negotiations involving environmental groups, farmers, state government officials, and others, agreement was reached on an arrangement more or less consistent with the original congressional intent. The increased flow of the two rivers, which merge before emptying into San Francisco Bay, also helped protect the Bay’s rich aquatic ecosystem, which is home to some 120 species of fish. 41

Variations of these efforts to restore river flows to supply natural systems with the water they need are now commonplace. In the United States, literally hundreds of smaller dams are being demolished in an effort to restore river flows and natural systems, including spawning runs. 42

In situations where growing water demand is exceeding the supply in more and more river basins, the challenge is to establish guidelines by which the various needs for water are met, recognizing that few will be fully met. Success hinges on having the institutions and a process by which water can be allocated among competing uses in a way that maximizes the contribution to society as a whole rather than to a small number of influential stakeholders at the expense of others.

ENDNOTES:

38. Sandra Postel and Brian Richter, Rivers for Life: Managing Water for People and Nature (Washington, DC: Island Press, 2003), p. 85.

39. Megan Dyson, Ger Bergkamp, and John Scanlon, eds., Flow: The Essentials of Environmental Flows (Gland, Switzerland, and Cambridge, U.K.: World Conservation Union–IUCN, 2003), p. 2.

40. Sandra Postel, Pillar of Sand (New York: W.W. Norton & Company, 1999), pp. 121–22.

41. Ibid.

42. John Tibbetts, “Making Amends: Ecological Restoration in the United States,” Environmental Health Perspectives, vol. 108, no. 8 (August 2000), pp. A357–A361.

Copyright © 2006 Earth Policy Institute