The drought affecting Sonoma and Mendocino Counties could have dire consequences for humans and animals reliant on the Russian River and its tributaries for water supply, according to panelists at a recent town hall.
The panel was hosted by Fifth District Supervisor Lynda Hopkins via Facebook Live on June 3.
Hopkins started out the evening by qualifying the severity of the drought and need for agencies, consumers and stakeholders to come together to effectively conserve water and manage its distribution, a theme throughout the evening.
“We are facing a severe drought in Sonoma County with reservoirs at record low levels and also critical fuel and moisture conditions. I want to thank every resident of Sonoma County who’s stepped up to conserve water,” Hopkins said. “I’ve heard some wonderful stories of people reusing water—in some cases multiple times, reusing it to water their plants, reusing it to flush their toilets. I appreciate the creative response. Because that is the way we are going to get through this drought. Everyone doing their part.”
On April 21, Gov. Gavin Newsom proclaimed a state of emergency while standing on the banks of the record-low Lake Mendocino, which, along with Lake Sonoma, is one of the two reservoirs that hold water for Russian River watershed. The Sonoma County Board of Supervisors declared a drought on April 27, when Lake Mendocino was at 43 percent of its target capacity and Lake Sonoma at 62 percent. Both were at the lowest they have been to date since being filled and have continued to drop.
The water resources of the Russian River watershed are managed by the Sonoma Water agency as well as the Army Corps of Engineers.
While Sonoma Water ensures water is properly diverted for human consumption, agricultural and commercial uses and environmental conservation reasons, the Army Corps of Engineers manages the reservoirs when overflowing and posing a flood risk.
Grant Davis, General Manager of Sonoma Water, said the special district formed in 1949 to manage the Russian River water resources supplies water to 600,000 people in cities and water districts in Sonoma and Marin County. They are also responsible for flood control and wastewater collection and treatment.
The Russian River is a 110-mile-long watershed, with the Lake Mendocino reservoir constructed in the 1950s. Lake Sonoma was constructed following the drought of 1976-77, the next worse drought since this one in the 127-year record.
“[The watershed] has the lowest water levels at this time of year that we’ve seen on record and we have a job to do to make sure that we keep enough water in case we do not get rain this fall and in the winter months,” Davis said.
Don Seymour, Water Resources Manager at Sonoma Water, gave a detailed explanation of the scope of the problem—and how controlling diversions from the reservoir while reducing consumption could help address the problem. Seymour’s projections assumed that the fall months of 2021 will continue to be dry, as there is no guarantee of a strong rainy season and resources must be managed accordingly.
If the fall remains dry, there is serious concern that Lake Mendocino could drain entirely, which would be an environmental disaster.
Sonoma Water and other agencies are obligated to manage water interests that conflict during times of scarcity. For instance, they are required to ensure certain levels of water are diverted to streams reliant on the Russian River watershed for supply. Some of these streams host fisheries and play a crucial part in the life cycle of salmon native to the area.
Reduced water flows could increase the temperature of the water while increasing harmful algal blooms, setting off a chain of events such as reduced dissolved oxygen and altered pH levels, which could be catastrophic to aquatic life.
By petitioning the state to give conditions the more severe “Critical” designation rather than the current “Dry” designation, a lower volume of water could be released into these streams. Coupled with at least a 20-percent decrease in consumption, crisis could be diverted.