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. Should a drenching storm loom, that water will be released, enabling Lake Mendocino to capture the new runoff and control flooding, the mission it was built to serve 60 years ago.
The goal is to head into summer with as much water in Lake Mendocino as possible. Army Corps officials, the phalanx of scientists who developed FIRO at a branch of UC San Diego and Sonoma Water, are confident it will work.