For the Sacramento River Settlement Contractors — a major water recipient in the Central Valley Project that grows much of the state’s rice — the proposed plan, compared to the Trump rules, would reduce supplies by an average of 6%. In dry and critically dry years, the same group of farmers would be cut by 10%, according to the federal analysis. Mooney said that under certain conditions, their water deliveries can be cut in half from their total allocation.

Still, they support it, said Thaddeus Bettner, the group’s executive director. He noted that five state agencies helped develop that proposal and “we want to support a measure that has that level of support.”

Water project is ‘death by a thousand cuts’

The Department of Water Resources, in its review of proposed state water project activities, predicted large increases in young fall run Chinook killed by the Delta pumps.

For example, juvenile fish kills at the pumping station would nearly double, to nearly 7,000 fish, in years with “below normal” rainfall. The fall-run Chinook is not subject to endangered species protection, but its low numbers over the past 15 years has led to a two-year closure of commercial and recreational fishing.

But Grimaldo, of the state water agency, said the capture of more fish won’t be a significant hit to the overall population. “Overall, (the State Water Project) contributes a very small percentage of the approximately 20-30 million juvenile hatchery salmon that are released annually into the Central Valley,” he said.

While the federal review suggests measures to help the fish and offset expected effects, the state’s environmental review, which anticipates insignificant effects, does not.

Pierre, with State Water Contractors, added that the purpose of the environmental review process is not to avoid all “take” of a species — it’s to allow “take.” Take is the technical term for disturbing, harming or killing a protected species.

But several of these species are already close to extinction, and even a small injury at this point can be cause for concern.

“The water projects are a death by a thousand cuts, and can we tell which of these cuts has the greatest effect?” said Carson Jeffres, a fish biologist at the UC Davis Center for Watershed Sciences. “Small changes in (long-term operation of the water projects) will not be a death blow, but they may just be another cut.”

Jeffres said climate change and invasive species are also responsible for the decline of the delta’s ecosystem, exacerbating the effects of dams, habitat loss, reduced flows and pumping stations.

Environmental advocates said the time has come for a major regime shift in how water is shared between user groups. Barry Nelson, a policy representative for the Golden State Salmon Association, said the federal Bureau of Reclamation dismissed the more fish-friendly option “out of hand.”

“How you can fix a system facing multiple extinctions without significantly changing the status quo is beyond me,” Nelson said.

Chris Shutes, executive director of the California Sportfishing Protection Alliance, also thinks it’s time for the farming industry to relinquish its legal right to so much water or at least take bigger cuts in dry times.

“The water contracts need to be renegotiated,” he said, referring to long-term supply agreements made decades ago between state agencies and agricultural districts. “They need to look at how to restore the system so that agriculture can remain sustainable but maybe at a different level than it is now.”

An estuary collapse

The overhaul of the Central Valley’s water management system comes amid an ecological meltdown in the Bay-Delta, which is California’s largest estuary. All Chinook salmon populations have crashed and salmon fishing has been banned nationwide for two years.

Delta Norse, once a common species, is now almost extinct. The small, silvery fish lives only in the Delta, and it has long been a potent figure in California’s water wars.

Long-finned smelt numbers have fallen precipitously from historic abundance. Managed as a threatened species by the state for 15 years, it was listed in July as federally endangered, and it appears to be following in the path of its cousin, the lesser delta smelt.

Concerned about yet another declining species, California is now evaluating whether white sturgeononce abundant, should be listed as endangered.

UC Davis Jeffres said more fish are on the verge of disappearing without major changes in water management. California must, he said, increase river flows during key times of the year while aggressively rebuilding wetlands and floodplains. He said efforts to restore flows have been “fiddling around the edges without doing anything on a large scale” to boost fish populations.

“If we don’t start thinking outside the box,” he warned, “our salmon will follow the norse” to extinction.