SCH Number 2022050575

Project Info

Title

Petitions Requesting Approval of Temporary Urgency Changes in Water Right Permits 12947A, 12949, 12950, and 16596 in Mendocino and Sonoma Counties

Description

The Sonoma County Water Agency (Sonoma Water) controls and coordinates water supply releases from the Coyote Valley Dam and Warm Springs Dam projects in accordance with the provisions of water rights Decision 1610, which the State Water Resources Control Board (State Water Board) adopted on April 17, 1986. Decision 1610 specifies the minimum instream flow requirements for the Upper Russian River, Dry Creek, and the Lower Russian River, which vary based on water supply conditions (Figure 1 ). Sonoma Water is filing temporary urgency change petitions (TUCP) requesting that the State Water Board make the following changes in the minimum instream flow requirements for the Russian River mainstem that are specified in Decision 1610 and Sonoma Water's water right permits: (a) a Critical water supply condition minimum instream flow of 25 cubic feet per second (cfs) in the Upper Russian River from its confluence with the East Fork to its confluence with Dry Creek, and (b) a Critical water supply condition minimum instream flow of 35 cfs in the Lower Russian River downstream of its confluence with Dry Creek to the Pacific Ocean. The changes are necessary in order to maintain viable operations to support municipal use, protect listed salmon ids, preserve stored water in Lake Mendocino and Lake Sonoma, and prevent violating the incidental take statement in the 2008 Russian River Biological Opinion issued under the federal Endangered Species Act. To allow Sonoma Water to optimally manage instream flows in the Upper Russian River and Lower Russian River, and associated reservoir storage, Sonoma Water is requesting that the TUCP minimum instream flow requirements be specified as a 5-day running average of average daily stream flow measurements with instantaneous minimum instream flows being no less than 10 cfs below the minimum in the Upper and Lower Russian River. This implementation of minimum instream flow requirements will allow Sonoma Water to manage stream flows with a smaller operational buffer, thereby conserving water supply in Lake Mendocino and Lake Sonoma.

2 documents in project