Delta Anxieties on Tap: Pump Shutdown to Save Small Fish is Big Concern Downstream.

By Matt Weiser and Jim Downing, The Sacramento Bee, Calif.

Jun. 3–The fate of a water supply serving two in three Californians has come down to tides, temperature and the mysterious movements of a tiny fish.

When the state Department of Water Resources on Thursday agreed to shut down its water export pumps in the Sacramento-San Joaquin Delta to protect the Delta smelt, it said the pause would last only seven to 10 days. The U.S. Bureau of Reclamation has not shut down its pumps, but drastically cut pumping at its own export facility.

The goal is to avoid killing more of the rare smelt in the pumps. The threatened fish, all juveniles this time of year, are scarcely bigger than a thumbnail and can’t yet swim strongly enough to resist the force of the pumps, which are powerful enough to reverse natural flows in the Delta and draw water in from the sea.

The duration of the shutdown depends on the fish, which in turn awaits its cue in an intricate dance of natural forces before it moves to safer waters.

But because numerous threats remain for smelt and other fish, water and wildlife officials said the shutdown may foretell more water disruptions to come as the crisis in the Delta deepens.

“I think everyone just hoped that our actions weren’t really damaging the Delta, that we could have our cake and eat it too,” said Peter Gleick, president of the Pacific Institute, an independent water policy research group in Oakland. “Well, we can’t. It is time we took the environment into account.”

The state Department of Fish and Game plans to monitor the smelt and water temperatures to see when they’ve reached safety. No one can say with certainty how long that will take.

Water agencies downstream are nervous.

“If they shut off all the pumps, the domino effect of that to the economy of the state would be unimaginable,” said Dennis Falaschi of the San Luis and Delta-Mendota Water Authority.

The smelt is one of six fish species declining in the Delta, and no magic prescription has been found. A state-appointed panel of experts is charged with designing a sustainable future for the Delta. Its report is at least a year away.

“Doing these emergency actions is a crummy way to manage any situation,” said Peter Moyle, a UC Davis biologist and coauthor of a Public Policy Institute of California report on the Delta.

“If the Delta smelt goes,” he added, “there are other fish in line to have the same thing happen to them. What you have is large parts of the Delta becoming a freshwater lake and lacking all the distinctive character that has made it a special place in the past.”

Smelt normally spawn in eastern portions of the Delta in winter, in main channels of the Sacramento and San Joaquin Rivers. During spring they feed in the central Delta, then move downstream to Suisun Bay in summer.

But the environment is now confining the smelt to the central and south Delta near the powerful pumps. A series of unusually high spring tides, with last month’s “blue moon” partly to blame, has flooded the Delta preventing smelt from moving downstream, away from the pumps.

The fish also depend on strong spring outflows to move downstream. Those have been hindered in recent decades by the state’s many dams, and most recently by the dry winter. The U.S. Bureau of Reclamation plans to help by maintaining stronger releases into the San Joaquin River from New Melones Reservoir.

The fish also wait on a temperature signal. Waters 77 degrees and warmer are considered deadly to smelt, so as the Delta warms in late spring they naturally seek colder water in the salt- and freshwater mixing zone of Suisun Bay. But the Delta has remained around 71 degrees.

“What the tidal cycles do is cause draining and chilling of the Delta that’s completely independent of how much flow is coming in (from upstream),” said Ted Sommer, a senior environmental scientist at DWR who is part of a team of experts monitoring the fish. “So our concern is that during a filling cycle, you’ve got more of a push that may move the smelt more into the Central Delta.”

Tides will decline in magnitude this week. But water temperatures aren’t yet increasing.

“These are fish with their own unique, independent behaviors, so 10 days may be enough time,” said Sommer. “But it may be much longer than that before their distribution changes.”

A prolonged wait could mean trouble for some water users.

One area at risk is Zone 7 Water Agency, which serves Livermore, Pleasanton and Dublin. It gets 80 percent of its water from the Delta and may have to adopt mandatory rationing and conservation measures if the pumps remain idle more than 10 days.

A cascade of cutbacks would hit farmers throughout the San Joaquin Valley.

First effects would be felt by farms that draw water directly from state and federal canals running between the Delta and San Luis Reservoir.

The State Water Project serves only one small water district along this stretch. The federal canal waters more than 140,000 acres, said U.S. Bureau of Reclamation spokesman Jeff McCracken, but much of that land has alternative supplies, such as water in the San Joaquin River.

Farmers south of Los Banos would still get some water from the 2.1 million acre-foot San Luis Reservoir, a holding pond for state and federal water projects.

But Friday, the reservoir was just over half-full, dropping at close to 2 feet per day.

In the near term, state and federal water agencies expect to supply most of their irrigation customers with water from reservoir withdrawals. But water managers are loath to draw down the reservoir so early in the irrigation season because it can crimp deliveries later in the year.

Because of the dry winter, state and federal agencies already had informed San Joaquin Valley farmers their Delta water deliveries would be 50 percent to 60 percent of their allocation this year.

Faced with an uncertain supply, farmers and irrigation districts are looking at their options.

Where possible, many irrigation districts and individual farmers can switch to other water sources, such as groundwater. Recent wet winters have replenished some aquifers.

When water is scarce, farmers tend to focus on sustaining so-called “permanent” crops — fruit and nut trees and grapevines — while abandoning low-value annual crops such as cotton. Sarah Woolf, spokeswoman for the huge Westlands Water District, in the San Joaquin Valley, said some cotton fields in her area already have been plowed under because of uncertain water supplies prompted by the dry winter.

Dry years also tend to generate a flurry of water sales from one farmer or irrigation district to another. Demand from growers desperate to keep trees or vines alive can quickly drive up prices. Westlands farmers pay roughly $75 an acre-foot for their federal canal water, Woolf said, but prices for short-term water contracts are already several times that.

Gleick said it is too soon to consider mandatory conservation measures.

“There’s a lot we could do to make the shutdown of the pumps less painful to water users,” he said. “If we wait long enough, conservation is going to mean deprivation.”

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