He won’t admit it, but Gavin Newsom is being played by Big Ag interests as he tries fruitlessly to negotiate a truce in California’s water wars.

The governor’s apparent willingness to play into the hands of monied, agri-business players at the expense of the health of the Sacramento-San Joaquin River Delta remains the biggest mystery of his short tenure. It also threatens to trash his reputation as a strong protector of California’s environment.

The Delta supplies water for 25 million Californians, including about one-third of Bay Area residents. Scientists agree that allowing more, not less, water to flow through the Delta and west toward San Francisco Bay is essential for protecting fish life and providing a clean supply of drinking water for current and future generations. That means restricting pumping of water out the south end of the Delta into Central Valley farmland.

The governor has been trying for months to get the major urban and ag players to reach a voluntary agreement on water flows from the Delta. His stated goal has been to avoid the lengthy lawsuits that follow a state mandate. But on Dec. 10, the Fresno-based Westlands Water District, the largest agricultural district in the nation, threatened to pull out of the talks. Westlands General Manager Tom Birmingham said “it would be impossible to reach a voluntary agreement” if Newsom followed through on his November pledge to sue the Trump administration over the federal government’s plan to pump more water south to Central Valley farmers.

It’s the same strategy Westlands used in September to pressure the governor to veto SB 1. The bill would have established as state standards the federal environmental protections that existed before Trump became president.

SB 1 offered Newsom the tool needed to thwart the Trump administration. It might have also given the governor leverage to bring environmentalists and farming interests to the table to reach a voluntary agreement on Delta water flows. But the governor caved to Big Ag interests in hopes that they would work cooperatively on a negotiated deal. We see how well that strategy worked.

The question now is whether Newsom will capitulate again to agriculture interests by backing down on his promise of a lawsuit to block the federal government’s planned increase of Delta water diversions.

The governor has repeatedly made clear that he “will rely on the best available science to protect our environment.” That science is unequivocal.

In the same week that Newsom vowed to sue the Trump administration, the state released a draft environmental impact report based on “a decade of science and a quantitative analysis of best-available data on flows, modeling, habitat and climate change impacts.” The report made clear that the operating rules proposed by the Trump administration “are not scientifically adequate and fall short of protecting species and the state’s interests.”

The scientists in charge of the drafting the federal government’s environmental impact plan said much the same. That is, until the Trump administration got wind of the conclusions and promptly replaced the scientists. In short order, a new report emerged saying pumping an additional 500,000 acre-feet (one acre foot of water is enough to supply two households for a year) to the Central Valley wouldn’t hurt the Delta’s health.

The ball is in Newsom’s court. The governor should follow through on his lawsuit against the Trump administration and act on the best available science to secure California’s fresh water supply.