A reduction in the amount of water sent south by the U.S. Bureau of Reclamation and State Water Project plants northwest of Tracy has been prompted by state fish and wildlife officials concerned that the number of Delta smelt killed by the pumps is close to the limit imposed by the Endangered Species Act.
Those officials say that, so far, 232 smelt have been reported killed by pumping stations. The annual limit is 305 of the fish, which many environmentalists consider a bellwether for the Delta’s overall health.
The result is that already some 700,000 fewer acre feet of water has been pumped out of the Delta in recent months.
The federal pumping plant send 250,000 fewer acre feet into the Delta-Mendota Canal, according to Frances Mizuno, assistant executive director of the San Luis and Delta-Mendota Water Authority, which operates the system. The rest of the total was a reduction in the amount pumped by the State Water Project into the California Aqueduct.
“That 250,000 acre-foot reduction translates into a 15 percent drop in allocations of our project’s water to agricultural users,” Mizuno said. “We’ll know for certain by next week, when the first allocation estimates of the year are issued.”
Last year, irrigation districts who rely on federal water from the Delta-Mendota received 45 percent of their contracted water supplies. At the start of this water year, with water levels in reservoirs still relatively high, it appeared allocations up to 35 or 40 percent could be anticipated.
But with curtailed pumping and a general lack of rainfall since Jan. 1, allocations closer to 20 percent might be realistic, said Rick Gilmore, manager of the Byron Bethany Irrigation District.
He said some land in the district relies solely on Delta-Mendota water, and new almond orchards recently planted in the area require more water than open ground.
Mizuno said the pumping restrictions to protect the smelt will continue into March, when protection for the Delta’s winter-run salmon will begin.
“We anticipate that reductions will continue until around the first of July,” she said. “We will be operating one to three pumping units, instead of five units at full capacity.”
Except for one section of the Byron Bethany Irrigation District, most local irrigation districts — principally the West Side and Banta Carbona district — receive their water from both river sources above the federal and state pumps and from the Delta-Mendota Canal.
Jim McLeod, president of the Banta Carbona district, said despite the dual sources, the prospect of lower water allocations from the canal is a major concern for his district.
He also cast doubt on the pumping impact on the smelt, saying that he has yet to see any proof of a higher-than-usual number of dead smelt.
“Delta smelt are captured at the fish screens at the pumping plants and then released live,” he said. “Show me the dead fish!”
According to McLeod, fish-protection controls placed on pumping out of the Delta for the past 20 years haven’t improved the smelt situation.
The problems with the smelt have given ammunition to those who support twin tunnels that would take water out of the Sacramento River and send it directly to the pumping plants, instead of allowing it to flow through the Delta.
The current version of the original peripheral canal is estimated to cost $14 billion by Gov. Jerry Brown’s office..
Opponents, especially farmers north of Tracy and west of Stockton, say that would degrade water quality throughout the Delta.
Federal and state water and wildlife officials have stated they are trying to work out programs to reduce the impact of reduced pumping levels on water users, but so far those programs are only in the talking stage.
• Contact Sam Matthews at 830-4234 or firstname.lastname@example.org.