The long-expected showdown between the Trump administration and the state of California over water, farmers and the Central Valley appears to be imminent. On. Aug. 17, Interior Secretary Ryan Zinke issued a memorandum declaring his staff had 15 days to draft a plan that would increase water for the region’s agricultural industry by reinterpreting relevant federal policies and laws and by targeting “unacceptable conditions” advocated by the state of California.

Zinke specifically cited the need to “streamline” the process under which the Endangered Species Act (ESA) and the National Environmental Policy Act are considered and invoked in Central Valley decisions. He wrote that this has prevented long-term changes in federal water decision-making.

Behind the bureaucratic language, it appears the Trump administration is taking dead aim at broad water policies that Central Valley House Republicans like Kevin McCarthy and Devin Nunes have long said valued the interests of declining fish populations in the Sacramento-San Joaquin River Delta over the interests of the region’s farmers, who have made the Central Valley the nation’s agricultural breadbasket.

But even if the Zinke deadline is met and the Interior Department has new water allocation rules and policies in place by the Sept. 1 deadline, quick change seems unlikely. That’s because environmental groups which have fought previous changes sought by the previous Republican presidents, in particular George W. Bush, have long found judges to be sympathetic to their interpretation of the ESA. A significant number of moderate GOP lawmakers also oppose major changes in existing green regulations.

The green coalition contends that the health of salmon and Delta smelt in Central Valley waterways and rivers is a proxy for the health of Northern California’s ecosystem. Greens say that giving more water to farmers by diverting some of the fresh water now pumped into the Sacramento-San Joaquin River Delta could lead to a disaster that affects the whole state – very much including the 19 million residents who deeply rely on water from the rest of the state that’s distributed by the giant Metropolitan Water District of Southern California.

Trump’s promises to Central Valley farmers during an August 2016 campaign appearance in the region foreshadowed Zinke’s order. But a more specific, recent cause may have been farmers’ complaints about the California State Water Resources Board, which took two days of public testimony last week on its plan to increase water pumped into the Sacramento-San Joaquin River Delta from February to June to shore up endangered salmon.

Farmers, allies also weigh court challenges

Just as environmentalists threaten legal action over how federal decisions affect Central Valley water use, those aligned with farmers vow court fights over the proposed state policy change.

“If they vote to take our water, this does not end there,” state Sen. Anthony Cannella, R-Modesto, told the Associated Press. “We will be in court for 100 years.”

While Trump was nearly doubled up in 2016 California voting by Democrat Hillary Clinton, he ran far better in farm regions. He won easily in the two counties with the state’s largest agricultural economies, taking Kern County by 55 percent to 40 percent and Tulare County by 53 percent to 41 percent.

But the larger war over how California’s limited water resources are used seems far from over. The compromise’s approval is sure to spur new court battles. It could also embolden House Republicans like McCarthy and Devin Nunes, R-Tulare, and conservative think tanks to seek further changes in federal policies.

Environmental groups are expected to sue over new rules which allow federal authorities in charge of water supplies in the Sacramento-San Joaquin Delta to deliver more water to farmers in periods of drought.

The Endangered Species Act has been a potent weapon for environmental groups, which have often succeeded in getting judges to adopt broad interpretations of provisions that have been used to protect the delta smelt and Chinook salmon in Northern California waterways. This thinking is reflected in a lawsuit filed in March by green groups, which say even the strong environmental stances of federal and state regulators under Democratic President Barack Obama and Democratic Gov. Jerry Brown don’t go far enough in providing fresh water to the delta.

Such tactics awaited George W. Bush after he became president in 2001. His administration was stymied in efforts to shift environmental policies by legal action and effective lobbying in Congress. By one tally, environmentalists won 27 of their 38 suits against the two-term president.

Endangered Species Act long a Republican target

But the same attitude seen in Natural Resource Defense Council lawsuits against Democratic administrations — why settle for a good result when more is possible? — could soon animate Republicans, especially those who have chafed at how much control the federal government has over land-use decisions in the West. Nunes in particular has long railed against federal indifference to the concerns and needs of Californians.

The Washington consensus is that Feinstein cut a deal because of the fear that a Trump administration would go much further in revamping interpretations of existing water and endangered species laws. This led her to make a major concession to McCarthy: Allowing the secretary of commerce and the secretary of interior to play a key role in determining in how water is allocated between the Delta and farmers.

That provision alone could turn California water policies upside down.

Trump’s nominee for commerce secretary, billionaire investor Wilbur Ross, doesn’t have high-profile views on land-use issues. His nominee for interior secretary, Montana Rep. Ryan Zinke, is open to the federal government allowing much more of its land to be used for oil and gas drilling, but has spoken of the importance of preserving public lands.

There is also the possibility that the Trump administration could target the Endangered Species Act itself — either through executive orders reinterpreting the law or by encouraging congressional action.

Conservative think tanks have long faulted the species act for far more than denying water to Central Valley farmers. It’s viewed as the California Environmental Quality Act is seen by business groups and conservatives in the Golden State: as a blunt, coercive tool to win land-use battles.

A 2007 report by the Dallas-based National Center for Policy Analysis offers a framework for the sort of policies the Trump administration could pursue.

The most decisive — and most controversial — would simply be for the secretaries of commerce and the interior to make it more difficult to a species to be designated as endangered and easier for a species to be taken off the protected list, reducing the authority now wielded by the U.S. Fish and Wildlife Service. Conservatives have long argued that designations of 1,300-plus native species and plants are excessive and arbitrary.