The winter rains have significantly improved our water storage capacity at Lake Sonoma and Lake Mendocino. While reservoirs are full, it’s still important to save water. Every drop we save now will be available in the summer when it’s needed for people and wildlife.
On December 14, 2022, the State Water Resources Control Board issued a Temporary Urgency Change Order in response to Sonoma Water’s petition to address significant reductions in flows into the East Fork Russian River through Pacific Gas and Electric Company’s (PG&E) Potter Valley Project (PVP) due to a transformer bank failure, as well as continuing drought conditions in the Russian River Watershed. Additionally, the Order temporarily allows the hydrologic index to be based on Lake Mendocino storage values, rather than the current index based on cumulative inflow into Lake Pillsbury.
Residents are encouraged to continue using water wisely and eliminate water-wasting activities. Learn more water-saving tips at savingwaterpartnership.org.
What is Sonoma Water doing in response to the drought?
Sonoma Water U.S. Army Corps of Engineers (USACE) have increased water storage capacity at Lake Mendocino by managing reservoir levels based on high-resolution weather forecast data. This innovative program is known as Forecast Informed Reservoir Operations (FIRO).
As a result of FIRO, Lake Mendocino is holding an additional 11,650 acre-feet of water.
A study is in progress to determine if FIRO can be used to improve storage in Lake Sonoma
Water releases by the USACE from Lake Mendocino and Lake Sonoma are necessary to prevent floods due to potential incoming storms and to sustain Russian River Watershed wildlife (i.e., endangered and threatened salmon species).
Sonoma Water and other local agencies are conducting groundwater banking studies to explore the possibility of recharging local aquifers during the rainy season. The results of one pilot project, known as the Aquifer Storage and Recovery project (ASR), were promising showing that groundwater levels increased and the water quality remained good.
Sonoma Water’s ASR is the first of its kind in the North Bay region, and its success provides a blueprint for future projects.
To ensure sustainable groundwater management in Sonoma County, Sonoma Water and other local agencies created three Groundwater Sustainability Agencies (Santa Rosa Plain, Petaluma Valley and Sonoma Valley).
Each Groundwater Sustainability Agency (GSA) successfully submitted a comprehensive Groundwater Sustainability Plan (GSP) for each basin to ensure sustained water availability and groundwater management over a 20-year period.
All three GSPs (Santa Rosa Plain, Petaluma Valley and Sonoma Valley) were approved by the California Department of Water Resources on January 26, 2023.
Explore various efforts and initiatives in the timeline below by clicking through the photos and text.
Sonoma Water and the County of Sonoma coordinated seven Drought Town Hall meetings to update the public on the drought emergency.
Experts provided the latest information on drought conditions and answered public questions. Participants received information on the prospects for a fourth year of drought and learned about programs to help private well owners.
To monitor our progress on achieving the 20% river diversion reduction requirement under the June 2022 TUCO (term 12), we’ll be issuing a weekly diversion report. This plot of cumulative diversions continues the same weekly reporting implemented last summer. Below is the current week’s plot of cumulative river diversions starting July 1st, shown in comparison to baseline 2020 diversions over the same time period.