The Bureau of Reclamation`s announcement recently that it would stop draining polluted irrigation water into a wildlife refuge in the Central Valley of California was only one of several hard choices faced by the agency responsible for big water projects in the West.
Within the coming decade, the engineering and construction bureaucracy, whose huge dams and long canals laid the foundation for the West`s economic and political rise, will run out of projects to construct. At the same time, some of its proudest achievements have been tarnished by the unintended environmental effects of altering the region`s natural water flows.
The decision to begin immediately on shutting off drainage into the California site, the Kesterson National Wildlife Refuge, caps years of controversy over the used irrigation water that flows into the refuge.
The runoff from about 42,000 acres of prime Central Valley farmland caused selenium, mercury and other chemicals found naturally in the soil, along with trace amounts of pesticides, to concentrate in the refuge.
The rising chemical concentrations from the runoff are suspected of causing deformities among wildlife at the refuge, 65 miles northwest of Fresno.
Elsewhere in the West, the bureau and the irrigation districts it supplies with water have encountered other problems.
The California Water Resources Control Board has charged the Imperial Valley irrigation district in southern California with wasting millions of gallons of scarce water because its irrigation system, built by the bureau, drains into the inland Salton Sea, raising its level and flooding nearby properties.
Salt levels in the lower Colorado River, meanwhile, have been sharply raised by the intensive damming and diversion of the river`s water, leading to a dispute with Mexico and the need to build a multimillion-dollar desalting plant below Yuma, Ariz.
To the bureau`s admirers and political supporters in the West, these problems are insignificant compared to what they see as the heroic scope of its reclamation projects that have watered an arid region and turned California and the rest of the West into the country`s fruit and vegetable basket.
``Let me put it this way,`` said Robert J. Hawk, a third-generation farmer in the Imperial Valley of California. ``Lettuce is 98 percent water, so without this water coming in here, your good folks up in New York City wouldn`t have that nice spot of green on their table in the middle of the winter.``
Since the United States Reclamation Act of 1902 was signed by Theodore Roosevelt, the bureau has measured its life in tons of concrete and acres of water to irrigate a parched landscape. Its engineers were often considered heroes by men and women still caught on the edge of the Dust Bowl, people like the Idaho farm couple, immortalized in one of the bureau`s most famous photographs, awaiting the arrival of reclamation water from the Snake River, who erected a front-yard sign that said they put their faith ``in God and U.S. Reclamation.``
Over the years, the bureau has spent nearly $8 billion building 700 dams, 16,000 miles of aqueducts, 35,000 miles of irrigation ditches, 275 miles of water tunnel and 241 pumping plants.
This vast network delivers 24 million acre-feet of water, enough to flood Indiana under 12 inches of water, to farmers annually. They irrigate 9 million acres with it to grow 55 million tons of food, fiber and forage annually.
But despite its triumphs, the bureau is approaching a watershed in its 82-year existence. The big rivers of the West have all been dammed, most of the readily irrigable land is already under the plow and the half-dozen large projects under construction are scheduled for completion in the next decade, with no new ones on the horizon.
Congress has not authorized a major new reclamation project since 1968 and is not likely to do so soon. To some of its members, reclamation has always rhymed with pork barrel. To farm-state members, reclamation money means more competition with Iowa corn or Mississippi cotton. Urban members argue that any money for water projects should go to treat their aging water and sewer systems.
The Reagan administration, meanwhile, seeks to cut the bureau`s budget by 20 percent, to $820 million, for the 1986 fiscal year, which begins Oct. 1, and is pursuing plans to merge it with the Army Corps of Engineers. That move could lead to the bureau`s submergence within the much larger arm of government.
Meanwhile, the 18 states the bureau serves that have been the focus of reclamation are themselves shifting ground. The growth of cities in the West has increased competition between farmers and urban dwellers for scarce water and has led to the spread of subdivisions out into farmland, sometimes leaving irrigation districts with more water than land to put it on.