The following is a press release from Sonoma Water:
On Wednesday, May 25 Sonoma Water (Sonoma County Water Agency) filed Temporary Urgency Change Petitions (TUCP) with the State Water Resources Control Board to establish a Critical water supply condition for both the upper and lower Russian River as the drought continues.
Under Critical water supply conditions, the Russian River would have minimum instream flow requirements of 25 cfs and 35 cfs in the upper and lower river, respectively. If approved, this change will allow Sonoma Water to continue the minimum instream flows that the river is currently operating under and preserve water supply in both Lake Mendocino and Lake Sonoma.
The current petitions also commit Sonoma Water and its retail customers to a (the cities of Cotati, Petaluma, Rohnert Park, Santa Rosa and Sonoma; the town of Windsor; and Valley of the Moon and North Marin water districts) 20-percent reduction in total diversions from the Russian River between July 1 and October 31 compared to the same time period in 2020.
“The Russian River watershed is facing severe drought conditions for the third year in a row and filing Temporary Urgency Change Petitions is essential to ensure the water supply for more than 600,000 people and the environment in Sonoma and Marin counties,” said Sonoma Water Director James Gore.
Without establishment of the Critical water supply condition, the water supply condition would be classified as Normal – Dry Spring 2, and the required minimum instream flows would lead to significant declines in the water levels in Lake Sonoma and Lake Mendocino, which have been depleted by three years of drought.
In addition to the drought, Lake Mendocino is also impacted by reduced inflows due to changes in the operation of PG&E’s Potter Valley Project as a result of an equipment failure and dry conditions in the Eel River watershed.
The current hydrologic index in Sonoma Water’s water rights permits sets minimum instream flow requirements that are out-of-date and based on inflow into Lake Pillsbury (in the Eel River watershed).The index is not based on Russian River watershed conditions, which are extremely dry.
With no significant rain for the last three years, Lake Mendocino and Lake Sonoma water supply levels are at historical low levels.
Current Water Supply Conditions as of 5/25/22:
- Lake Mendocino: 56% of target water supply curve
- Lake Sonoma: 57% of water supply capacity
In addition to the TUCP filings, Sonoma Water and the Sonoma Marin Saving Water Partnership continue to implement a comprehensive public outreach campaign seeking the community’s help in saving water. The Partnership represents 13 water utilities in Sonoma and Marin counties who have joined together to provide a regional approach to water use efficiency.
“It is important that all of us do our part to save water now. We are all in this drought together and can make a difference as we’ve done for the last two years,” said Gore.”
Sonoma Water will continue consultations with staff from the State Water Resources Control Board, North Coast Regional Water Quality Control Board, National Marine Fisheries Service and California Department of Fish and Wildlife to address any water quality, fishery, or public health and safety concerns.
To read the TUCP and learn more about the drought, please visit www.sonomawater.org/tucp