California's Water Projects Are Pumping at Maximum Levels

This past week presented a remarkable series of events in the ongoing struggles over how to manage the San Francisco Bay-Delta. First, the largest agricultural water district in the nation and the leading proponent of exporting more freshwater out of the Delta - the Westlands Water District - was levied reportedly the largest fine ever issued by the SEC against a municipal bond agency for cooking the books. The SEC quoted Westlands' general manager Tom Birmingham as bragging to his board about engaging in "a little Enron accounting" and misleading investors in order to beef up the district's bond rating without having to raise water rates for its agribusiness customers. The very same day that the SEC announced the fine, the Fresno Bee editorial board called for increased pumping from the massive water project pumps in the south Delta for the benefit of Westlands and other south-of-Delta agriculture, based on the demonstrably false claim that the pumps aren't operating at the maximum levels allowed under biological opinions designed to prevent wiping out several runs of native salmon, steelhead, sturgeon, smelt and other fish perched on the edge of extinction. The source of the Bee's misinformation appears to be the Westlands Water District, with the District's deputy general manager quoted in the editorial as stating that "[t]his should be a time to maximize water supply deliveries." Then, on Friday, Senator Feinstein repeated the same call for increased pumping from the Project pumps in the Delta, based on the same false assertion that the "biological opinions would allow more pumping." The Senator's press statement cited information from another Westlands' proxy, the San Luis Delta-Mendota Water Authority.

But the claim that the agencies could lawfully pump more under the biological opinions is simply wrong, with the Bureau of Reclamation stating in no uncertain terms that "We're pumping as much as we legally can." As shown below, the data back them up. So why are normally credible sources ignoring the hard data and the federal and state agencies that operate the water projects and lending credence instead to the discredited Westlands Water District, with its clear financial interest in increasing the supply of cheap water from the Delta at the expense of the Bay-Delta estuary and its public trust resources? When did truthiness trump the authority of facts?

The facts are well-established. The massive pumps of the federal Central Valley Project and the State Water Project in the south Delta exert a powerful influence on river flows when they operate at high levels, causing some rivers to flow backwards and generally changing the natural westerly flow of water through the Delta to southerly. That hydrological influence presents a wide array of hazards to threatened and endangered salmon and other fish trying to survive in or migrate through the Delta. Those hazards include getting sucked into the pumps, a process which kills many fish. That so-called "salvage" is occurring right now, primarily of endangered winter run chinook salmon and steelhead who are in the Delta and trying to make their way from their upstream nurseries to the ocean.

But direct mortality from the pumps is a small part of the total harm caused by the pumps. When pumping is high, the Projects also pull fish off of their migratory path into the hostile interior Delta where they suffer a whole range of harms. Here's how the Ninth Circuit Court of Appeals summarized it when rebuffing challenges from Westlands and others to the salmon biological opinion (at pages 58-60):

  • "First, NMFS explains how, over the past half century, the Projects' operations have worked to degrade the environment in the interior delta, converting a thriving river system into an unnatural inland lake-like habitat ill-suited to many native species."
  • "Second, NMFS concludes that continued CVP/SWP operations (specifically pumping from the Jones and Banks facilities) cause fish outmigrating through the main channels of the Delta to divert into intersecting channels that split off from the main rivers and lead towards the inner delta."
  • "Third, fish that are drawn through intersecting channels and into the inner Delta have a lower survival rate than fish that remain in the main Delta. ... Not all of these fish are killed in pumping plants; many are eaten by non-native predators, trapped by non-native plants, or fall prey to pollution in the inner Delta."

To lessen these impacts, which were driving several runs of salmon and other species to extinction, the fishery agencies set maximum pumping levels for the Project pumps during periods in the winter and spring when threatened and endangered fish are vulnerable. Those levels are described in terms of limits on the degree to which the pumps can make the Old and Middle Rivers flow backwards. This Old and Middle River ("OMR") flow limit is expressed as a negative - since the rivers are flowing backwards. The maximum allowed under the biological opinions is -5,000 cubic feet per second (or "cfs"). Since the CVP and SWP operators can't operate to this precise limit, the biological opinions call for them to meet a 14-day rolling average. So if the pumps cause the Old and Middle Rivers to flow more negative than 5,000 cfs on one day, they have to ramp down the next to bring the average back to the right level.

Since about February 10th, because several salmon, steelhead, smelt and other fish are in the Delta and vulnerable to the pumps, the fishery agencies have implemented the -5,000 cfs OMR limit under both biological opinions. And the water projects have been operating to that limit. Here's the OMR flow chart posted on Reclamation's website:

March OMR flow data.PNG

What this chart shows is that the Projects are pumping at the maximum - they can't pump any more without going over their -5,000 cfs limit since the 14-day average is right up to the limit.

It's disappointing that these verifiable facts aren't driving the debate in some quarters, which appear to be relying instead on the statements of those with a vested interest in pumping more water from the Delta, despite the fact that those making the statements were recently fined by a federal agency for misleading people for financial gain. Truth, rather than truthiness, should drive our policy choices in the Delta.

About the Authors

Kate Poole

Senior Director, Water Division, Nature program

Join Us

When you sign up you'll become a member of NRDC's Activist Network. We will keep you informed with the latest alerts and progress reports.