The Modesto and Turlock irrigation districts took a key step Tuesday morning toward using Don Pedro Reservoir for perhaps another half-century.
Their boards voted 5-0 at separate meetings to file a final license application with the Federal Energy Regulatory Commission, a huge set of documents with many details on how they would manage the reservoir. A crucial issue – how much water to release for fish in the lower Tuolumne River – remains unsettled because studies are ongoing.
The license would replace one granted in 1966, which led to completion of Don Pedro Dam in 1971. In most years since then – 2014 not among them – the reservoir has provided ample irrigation water and hydropower. It also supplies part of the drinking water in Modesto and a few smaller communities.
MID and TID had planned to seek a new license in 2016, just as the old one expired, but FERC is granting annual extensions so the remaining studies can be done. The target now is 2019.
“We’re a long way from home, but it’s so vital to this district,” TID board Chairman Ron Macedo said just before the vote.
The districts expect to spend more than $50 million on the relicensing studies and changes in reservoir operations to provide for fish and other needs. TID is paying 68.5 percent of the cost, reflecting its share of the water and hydropower.
The districts are trying to get another 50-year license, but it could be shorter, said Steve Boyd, TID director of water resources and regulatory affairs.
Farmers and their allies have urged FERC to grant a new license that does not require a larger volume of lower-river releases. They note that Don Pedro supplies nearly 210,000 acres of farmland, which in turn supports tens of thousands of jobs in processing plants and other businesses.
Environmental groups seek higher flows, which they say would benefit fish and provide for small boats and other recreation near Modesto and other riverside locales.
The Tuolumne is a world-renowned stream, rising in the glaciers of Yosemite National Park and featuring a whitewater run north of Groveland. Along the way, it flows into Hetch Hetchy Reservoir, which supplies San Francisco and nearby cities, and then into Don Pedro.
The lower reservoir, which can hold up to 2.03 million acre-feet of water, is the largest under local agency ownership in California. It has helped MID and TID weather dry years better than much of the San Joaquin Valley, although farmers this year are getting roughly half of their accustomed deliveries.
Don Pedro also has helped control floods, except in 1997, when an unusually wet storm melted much of the snowpack and put riverside parts of Modesto and nearby areas underwater.
In the final application, the districts said they are committed to continued recreation on and around Don Pedro, including boating, fishing, camping and other uses. They also pledged to protect historic sites and sensitive plants in the vicinity, along with winter habitat for bald eagles from the north.
The relicensing comes at the same time the State Water Resources Control Board is considering a proposal to sharply increase Tuolumne flows to enhance the Sacramento-San Joaquin Delta.