Russian River water use cutbacks on hold until at least July

Water rights holders in the Russian River watershed can breathe easy for at least a few weeks longer.

Staff for the State Water Resources Control Board had predicted water diversion curtailments would likely be imposed beginning June 16, but they now say they won’t be needed until at least the beginning of July.

That means ranchers, grape growers, municipalities and community water districts can continue to draw water from the river and its tributaries for a couple more weeks before supplies in Lake Mendocino and potentially Lake Sonoma drop low enough for the state to declare there’s no longer enough water available for certain rights holders to take.

Lake Mendocino is currently below 58% of the water supply target for this time of year. The lake furnishes the water that keeps the upper Russian River flowing during the summer months, once natural runoff and seepage no longer feed the stream.

Water managers are obligated to maintain enough water behind Coyote Dam to support federally protected fish and supply basic human health and safety needs throughout the year. When there isn’t enough water, rights can be curtailed for some people. Last year, rights were curtailed for 1,800 users.

Lake Sonoma is below 56% of its water supply capacity, but is about 2½ times as large as Lake Mendocino upstream, so its stores can last longer. But, even though the region received more rainfall this past winter than in either of the previous two — about 77% of normal throughout the watershed — Lake Sonoma’s storage level closely matches last year. Both reservoirs have multiyear deficits to make up.

All water rights holders are still required by state order to monitor the water board’s curtailment status list to stay current.

The delay in curtailments has the benefit of allowing state water board personnel to evaluate the enrollment and breakdown of participants in a groundbreaking voluntary water sharing agreement intended to allow those with older, “senior” water rights who are least likely to be curtailed to share the pain with those who are first in line to have their rights suspended.

Those participating must agree to use less water than they are allotted so those who are curtailed can use some of it rather than have none at all.

Participants have until June 20 to enroll. Water board staff will then determine if there are enough participants, and enough senior rights holders among them, for the program to work this year.

More information is available at waterboards.ca.gov/drought/russian_river/voluntary_program.html and at waterboards.ca.gov/drought/russian_river/.

You can reach Staff Writer Mary Callahan at 707-521-5249 or mary.callahan@pressdemocrat.com. On Twitter @MaryCallahanB.