With sunny 75-degree days ahead, barbecues hot, picnics packed and that garden ready to till, it’s easy to forget what drought-stricken Sonoma Valley really needs is more rain. As the rainy season wraps up, water officials are planning how to manage water for the rest of this dry year.
On April 7, the Sonoma County Water Agency met with its water contractors from throughout the region, including the City of Sonoma and Valley of the Moon Water District, to provide an update on current reservoir conditions in Lake Sonoma and Lake Mendocino, and to determine what efforts need to be made to conserve during the ongoing statewide drought.
SCWA spokeswoman Ann DuBay said the agency and water contractors determined that, although the drought remains, mandatory rationing “does not appear to be on the horizon” for Lake Sonoma users. In Sonoma Valley, a majority of the water supply comes from that water-agency managed reservoir. DuBay said contractors using this supply would continue with voluntary 20 percent water conservation as requested by Gov. Jerry Brown earlier this year.
Winter rains, especially those in February, have made a significant impact on water storage levels, SCWA spokesman Brad Sherwood said. February 2014, he noted, was the 13th wettest February on record and water storage levels and rainfall have surpassed those during the benchmark 1977 drought year.
The outlook for the water agency’s Lake Mendocino reservoir, which is much smaller than that at Lake Sonoma to begin with, is less positive, DuBay said. The Ukiah region is still facing one of the driest years on record and areas that rely on water from Lake Mendocino and the upper Russian River, from Healdsburg and above, will continue with the mandatory conservation efforts already in place as issued through their water contractors.
Rainfall in Ukiah is at 47 percent of its average, while it is at 62 percent of average in the Santa Rosa area, DuBay said.
The lower Russian River water supply system, DuBay said, moved from a “critical” designation to a “dry” designation, based on storage thresholds approved by the State Water Resources Control Board’s recent order approving a change to how SCWA measures water supply levels in the reservoirs. The upper river supply conditions remain critical.
DuBay said a technical advisory group for water contractors meets monthly to stay abreast of supply levels and determine the appropriate courses of action during the drought.
Weather predictions for later this year may indicate wet conditions. Earlier this spring, the National Oceanic and Atmospheric Administration issued an official El Nino watch. While forecasts show possibilities of very wet weather, SCWA Chief Engineer Jay Jasperse said stringent water management until that wet weather hits, which is usually in the latter part of the year, is especially crucial.
Once every few years, he explained, a warming of the central Pacific occurs, from a combination of wind and waves in the tropics, to form an El Nino. Early signs of El Nino are already appearing hundreds of feet below the ocean’s surface, according to NOAA reports, but an official El Nino season will not be declared until later this year. El Ninos are usually strongest from December to April.