A federal environmental analysis recommends relicensing the Don Pedro hydroelectric project and accepts a Modesto and Turlock irrigation district plan for well-timed flows to boost salmon in the Tuolumne River.
The flows, combined with other measures to assist spawning and outmigrating young salmon, would commit less water to the environment than a State Water Resources Control Board plan that’s unpopular in the Northern San Joaquin Valley.
But the Federal Energy Regulatory Commission, which is considering a new license for Don Pedro, balanced the environmental measures with projected economic impacts to the region, district officials said. FERC’s environmental review released last week is considered a major milestone in efforts to relicense a facility, 40 miles east of Modesto, that supplies electricity for homes and businesses in most of Stanislaus County.
Most of the measures to benefit salmon were first proposed in a management plan for the Tuolumne, and the complete package was incorporated in a 15-year voluntary agreement that was negotiated last fall with the California Department of Fish and Wildlife and Department of Water Resources.
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FERC’s environmental review is not final. The State Water Resources Control Board needs to approve the voluntary agreement before the terms are folded into the FERC relicensing of Don Pedro.
“Approval of our voluntary settlement agreement will be the last regulatory hurdle to complete the FERC license,” TID Board Member Michael Franz said Friday. “We remain hopeful the state water board will accept the agreement.”
The MID, TID and San Francisco Public Utilities Commission are opposing a Dec. 12 state water board decision, which requires 40 percent unimpaired flow in the Tuolumne, Stanislaus and Merced rivers. They charge the water board requirements would result in drastic irrigation cuts, severe damage to the region’s farm-based economy and water rationing in Bay Area cities.
Local officials were relieved last week when Gov. Gavin Newsom appointed a more moderate water board chairman, Joaquin Esquivel, and pledged support for voluntary agreements with water districts to increase depleted salmon populations and improve the San Joaquin-Sacramento delta.
The irrigation districts could present a more detailed voluntary agreement to the state water board in the coming months, though a decision could be a year away.
Terms of agreement
MID and TID say their agreement to increase salmon is not an attempt to avoid the environmental issues but is supported by scientific studies and the districts’ historic knowledge of the river. The districts would join with water agencies in the San Joaquin and Sacramento river watersheds in a $1.7 billion program for restoring salmon and reviving the delta with an additional 700,000 acre feet of water.
The flows, including dry year relief, would start immediately after approval and would be pegged to annual precipitation in the Tuolumne watershed. To help salmon smolts moving downstream, pulse flows of 2,750 cubic feet per second would last for 20 days in March in normal to wet years. The plan calls for 18-day pulse flows in below-normal water years, two-week flows in dry years and nine-day pulses in critically dry years.
To visualize the river running at 2,750 cubic feet per second, water ran at 3,000 cubic feet per second between the Tuolumne’s banks over the weekend to allow for storm runoff.
During a multiyear drought, the districts would maintain the environmental flows in a below-normal water year. The two districts, San Francisco and state officials would confer on what water is available for fisheries in an extended drought.
The state expects the MID, TID and San Francisco to work on identifying an additional source of drought relief for fisheries. One possible solution is banking excess water underground after wet winters and extraction to support additional flows in a dry spell.
In other proposed measures recognized in the federal environmental analysis, Don Pedro reservoir’s minimum level could be lowered by 50 feet, freeing up 150,000 acre-feet for water needs in the longer droughts predicted with climate change. In addition, minimum streamflows would be maintained for aquatic species in the lower Tuolumne.
In October, water releases of 1,000 cfs would clean gravel in the streambed for spawning. The MID and TID would still meet obligations to agriculture and Modesto water customers under the new flow regime, except in critical water years, “when only 88 percent of irrigation demand would be met compared to 92 percent under current conditions,” the federal analysis says.
Efforts to control nonnative bass that feast on the young salmon would include a permanent barrier in the river, fishing derbies and netting.
The districts also propose a $38 million fund for habitat improvements.
The permanent barrier and fish-counting weir are not recommended in the federal staff analysis, which doubted that efforts to suppress predatory species would be effective. “Similar predator removal efforts by the California Department of Water Resources did not noticeably reduce salmon mortality,” the document says.
The staff analysis predicts that flow and habitat measures will improve conditions for salmon and decrease habitat for predatory fish.
Terms of the voluntary agreement with the state do not include a salmon hatchery on the Tuolumne. The MID will present details of the voluntary agreement at landowner meetings set for 5:30 p.m. Feb. 27 at the Waterford Community Center and 5:30 p.m. Feb. 28 in the district board room in downtown Modesto.
FERC plans to hold public meetings in Modesto on the environmental document in late March.
Oakdale and South San Joaquin irrigation districts, serving water users on the Stanislaus River, were not able to complete agreements with the state agencies before the water board decision Dec. 12 approving the 40 percent unimpaired flows for the three rivers. Those two districts, along with MID, TID and Merced Irrigation District, are opposing the Dec. 12 decision in lawsuits.
“We were fairly close to getting to an agreement,” SSJID General Manager Peter Rietkerk said. “After (the Dec. 12 water board decision), we were under the impression we were going to keep negotiating with the state. For whatever reason, we have not been invited back to the table.”
Some prime areas for salmon habitat improvements on the Stanislaus have been identified and a study on predation was funded last year.
“The second phase would be starting some predation suppression on specific reaches of the Stanislaus and checking to see how it (affects) mortality of salmon moving out of the system,” Rietkerk said.