The environmentalists and state and federal biologists fighting to save the Delta ecosystem seemed to gain ground in 1989, when the National Marine Fisheries Service determined that populations of winter-run chinook salmon -- the radiant, blushing creatures that were once the mainstay of the San Francisco fishing fleet -- were so low that it classified them as "threatened" under the Endangered Species Act.

Against that backdrop, in 1992, the Democrat-controlled Congress passed the Central Valley Project Improvement Act, the brainchild of California Rep. George Miller, who was determined to give environmental concerns an explicit place in water politics, and New Jersey Sen. Bill Bradley, chair of the Senate Committee on Energy and Natural Resources. The law, which was the first attempt to create a balance between economic and ecological needs for water, pried a big chunk of water away from the Central Valley Project's irrigation districts and re-dedicated it to the environment. "This statute was like a little mini revolution," says Cynthia Koehler, a senior attorney and the California water legislative director for the Environmental Defense Fund. "There was nothing like it before or since that really seriously tried to reform how a federal (water) project worked."

The farmers who buy their water from the federal government were considerably less delighted. "We'll do anything and everything to keep from being harmed," Jason Peltier, then a point man for many of the irrigation districts, told the San Francisco Chronicle. "If that means obstructing implementation (of the 1992 law), so be it."

Those who sought a higher priority for the Delta's ecological needs chalked up another win two years later. With substantial nudging from the Democratic Clinton administration, California's main water players signed an agreement called the Bay-Delta Accord. Republican Gov. Pete Wilson compared it to the Oslo Peace Accords that Israel and Palestine had just signed, and declared, "Peace has broken out amid the water wars."

One of the major goals of the Bay-Delta Accord, which was to last three years, was to protect fish like the chinook that were already listed as threatened or endangered, and "to create conditions in the Bay-Delta Estuary that avoid the need for any additional listings." In signing the deal, the water agencies agreed to give up as much as 1.1 million acre-feet of water a year, just slightly less than a quarter of what they had received, on average, over the previous decade.

For them, the deal was a strategic compromise. They received a promise that the federal government would not take any more water than that, essentially shoring up the security of their remaining supplies. When Clinton's secretary of the Interior, Bruce Babbitt, signed the Accord, he said, in a quote carried in the San Jose Mercury News: "Basically, what we're saying is a deal's a deal. We've made a deal, and if it turns out there are additional requirements of any kind, it'll be up to the United States and the federal agencies to find the water."

But in spite of the optimism surrounding the Bay-Delta Accord in 1994, it merely led to yet more fights over the promises and commitments the Accord actually entailed. One that was particularly bitter still colors Delta politics to this day.

The biggest portion of the 1.1 million acre-feet per year for fish was the 800,000 acre-feet that Congress had reappropriated two years earlier, in the Central Valley Project Improvement Act. That water was explicitly intended to help double populations of salmon and steelhead, an ocean-going trout. The responsibility for managing it was assigned to the U.S. Fish and Wildlife Service -- an agency that, until then, had been "just basically tin-cupping, going out there with our hand out" for water, says Jim McKevitt, a Fish and Wildlife Service veteran who is now retired.

Practically overnight, the Service was transformed from the province of guys in hip-waders mucking around obscure Delta backwaters into one of the largest water agencies in California. No matter how you slice it, 800,000 acre-feet is a lot of water -- enough to fill 29 million semi-truck tankers. The agency's managers visualized that water as a flexible, quick-response cache -- reserved behind dams when necessary and used to "shape" flows in streams, rivers and the Delta to more closely approximate the yearly fluctuations the fish had evolved with. The more flow they could create at the crucial times, the less the fish would be affected by the pumps' draw.

But by then, the aggrieved farmers felt that the Clinton administration was acting in bad faith, determined to wrest that water from them in ways that would damage their enterprises as much as possible. "The views of the politicals" -- the political appointees -- "in the Clinton administration seemed to be, 'We're gonna right the wrongs of the past, and we're gonna put those people down where they belong,' " Peltier says. "It was like open season on the water users."

And so, in 1997, Westlands, together with a broader coalition of water agencies, sued the Clinton administration, demanding that it abandon its recently released proposal for strategically deploying the 800,000 acre-feet to help the fish. The case dragged on, and then in 2001, the farmers gained a powerful ally when Republican George W. Bush became president.

Bush appointed Gale Norton, an oil and gas lawyer from Colorado, as Interior secretary. Bennett Raley, another Coloradan who had long experience as a lawyer for that state's largest irrigation district, became Norton's assistant secretary for water and science. And Peltier -- who had once threatened to do "anything and everything to keep from being harmed" by the law that earmarked 800,000 acre-feet for fish -- became a special assistant to Raley, advising him, as Norton would later officially note, on issues related to the Delta.

Oliver Wanger, a federal district judge in Fresno who was appointed by President George H.W. Bush in 1991, was just then taking up critical questions about how much water the Fish and Wildlife Service actually had to work with to protect salmon. Even within the federal government, that issue had generated considerable antagonism between the Fish and Wildlife Service and the Bureau of Reclamation, the water-supply agency that has traditionally aligned itself closely with irrigation districts. The Bureau argued for a restrictive interpretation of how much water the Fish and Wildlife Service could get -- a position that the Service, in its own analysis, noted was "largely motivated by pressure to increase the (water) allocation to south of Delta agricultural users."