Coyote Dam – Enviro Updates

Guy Kovner, THE PRESS DEMOCRAT

Dam operators are planning to store nearly 4 billion extra gallons of water this winter in Lake Mendocino, the reservoir near Ukiah that plays a critical role in providing water for residents, ranchers and fish along the upper Russian River and to communities in Sonoma and Marin counties.

Retaining that much more water — enough for about 97,000 people for a year — comes about as a four-year and $10 million program, proven in computer models but not in practice, gets its first field test.

The program, blending high-tech weather forecasting with novel computer programming, is intended to pinpoint the arrival of rain-rich atmospheric rivers that have been both a drought-busting blessing and a flood-causing curse to the Russian River region.

It evolved from a searing lesson water managers got six years ago, when they released more than a third of the reservoir’s allowed capacity in anticipation of storms that never arrived. Then the state’s prolonged drought set in.

Under the new program, called Forecast Informed Reservoir Operation, or FIRO, the Army Corps of Engineers, which operates the reservoir, will hold onto the extra water as long as no atmospheric river is imminent.

Guy Kovner, THE PRESS DEMOCRAT

In early 2014, after fewer than 8 inches of rain had fallen in the upper reaches of the Russian River the previous year, Lake Mendocino dwindled to a third of its capacity, exposing acres of bare ground, and Mendocino County supervisors declared a drought emergency.

“How many times do we have to knock ourselves on the head before we get it?” then-Supervisor John Pinches asked during the board meeting. “Folks, we’ve got to come up with another water supply.”

The irony, in retrospect, is that a major addition to the reservoir near Ukiah — boosting its capacity by 25 billion gallons — had been planned by the Army Corps of Engineers more than 50 years ago. But with California in the midst of a five-year drought, the plan was gathering dust on the shelves of the federal dam-building agency.

A coalition of local agencies, including Mendocino County and the city of Ukiah, already had paid $617,000 toward a feasibility study that would determine if the benefits of raising Coyote Valley Dam by 36 feet justified the cost of about $320 million.

But without more money, Corps officials said in 2014 the study could not move forward.

Now, with the prospect of drought and hotter weather considered California’s “new normal” due to climate change, new hopes have arisen for the relief Pinches and others have sought: More water in Lake Mendocino to quench the needs of residents, farmers and fish along 75 miles of the Russian River from Redwood Valley to Healdsburg and contribute to the Sonoma County Water Agency’s deliveries to 600,000 customers in Sonoma and Marin counties.

Environmental Center of Sonoma County

Tag: Coyote Dam

Advance in storm forecasting allows Lake Mendocino to hold more winter runoff

Decades-old project to raise Lake Mendocino dam gets a boost