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

2 Documents in Project


SCH Number
Public Agency
Sonoma County Water Agency
Document Title
Petitions Requesting Approval of Temporary Urgency Changes in Water Right Permits 12947A, 12949, 12950, and 16596 in Mendocino and Sonoma Counties
Document Type
NOE - Notice of Exemption
Document 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 water supply conditions for the Russian River and the minimum instream flow requirements for the Upper Russian River, Dry Creek, and the Lower Russian River, which vary based on hydrological conditions and cumulative inflow into Lake Pillsbury as the hydrologic index. Sonoma Water is filing temporary urgency change petitions (TUCPs) requesting that storage thresholds in Lake Mendocino be used as the hydrologic index to determine the water supply condition in the Russian River watershed.

Contact Information

Connie Barton
Agency Name
Sonoma County Water Agency
Job Title
Senior Environmental Specialist
Contact Types
Lead/Public Agency / Parties Undertaking Project


Mendocino, Sonoma
Countywide, Northern California, Unincorporated
Other Location Info
The proposed action would occur in Mendocino and Sonoma counties at Lake Mendocino, in the Upper Russian River from Coyote Valley Dam/Lake Mendocino to the confluence with Dry Creek, Dry Creek downstream of Warm Springs Dam/Lake Sonoma, and in the Lower Russian River from the confluence with Dry Creek to the Pacific Ocean. Figure 1 shows the minimum instream flow requirements for the Russian River system. Communities and cities along the Russian River include Ukiah, Hopland, Cloverdale, Geyserville, Healdsburg, Forestville, Mirabel Park, Rio Nido, Guerneville, Monte Rio, Duncans Mills, and Jenner.

Notice of Exemption

Exempt Status
Categorical Exemption
Type, Section or Code
Section 21080(b)(4), State CEQA Guidelines 15269(c), 15301(i), 15307, 15308. Government Code section 8571
Reasons for Exemption
A. Actions to Prevent or Mitigate an Emergency California Public Resources Code, Division 13, Section 21080(b)(4) provides that specific actions necessary to prevent or mitigate an emergency are exempt from CEQA. The emergency conditions are due to the drastic reduction of potential Eel River water imports through the PVP resulting from the inoperability of the powerhouse for the foreseeable future. The volume of imported Eel River water that can be transferred with the powerhouse being inoperable results in little or no correlation between cumulative inflow into Lake Pillsbury and the hydrologic condition in the Russian River. Without the proposed changes, the applicable minimum instream flow requirements may require releases of water from Lake Mendocino and Lake Sonoma at levels that would risk significant depletions of storage to severely low levels. Such depletions in storage could cause serious impacts to human health and welfare and reduce water supplies needed for fishery protection. Sonoma and Mendocino were the first counties placed under a region-specific drought state of emergency on April 21, 2021, by Governor Gavin Newsom. The Sonoma County Board of Supervisors took action on April 27, 2021, proclaiming a local emergency due to drought conditions in support of actions needed to mitigate the adverse environmental, economic, health, welfare and social impacts of the drought. As required by Government Code section 8630, the Board of Supervisors must review the proclamation of local emergency every 60 days and determine if there is a need for continuing the local emergency. The Sonoma County Board of Supervisors has approved the continuation of the drought emergency conditions every 60 days since April 2021, with the most recent extension occurring September 13, 2022. It is expected that drought emergency conditions will remain in effect through 2022. B. Actions by Regulatory Agencies for Protection of Natural Resources and the Environment CEQA Guidelines Sections 15307 and 15308 provide that actions taken by regulatory agencies to assure the maintenance, restoration or enhancement of a natural resource and the environment are categorically exempt. Sonoma Water is proposing temporary urgency changes to its water right Permits 12947A, 12949, 12950, and 16596 that the State Water Resources Control Board, as the regulatory agency, will consider and potentially approve. Those changes are necessary in order to maintain viable operations to support municipal use, protect listed salmon species, address water supply conditions at Lake Mendocino and Lake Sonoma, and prevent Lake Mendocino from declining to a storage level at which the reservoir may no longer be functional in light of the extremely dry hydrology the region experienced in water years 2021 and 2022. Approval of the TUCPs would provide alternative storage thresholds and criteria for determining minimum instream flow requirements for the Russian River that would be based on a more accurate assessment of water supply conditions in the Russian River watershed. This would result in minimum instream flow requirements that more likely can be sustained with releases from Lake Mendocino and Lake Sonoma without severely depleting storage. C. Governor’s Drought Proclamation Government Code section 8571 authorizes the Governor to suspend certain regulatory requirements, including CEQA, under emergency conditions. Section 7 of the Governor’s April 21, 2021, Drought Proclamation suspended CEQA to address “the acutely dry conditions in the Russian River Watershed” through the State Water Board’s consideration of modifications of reservoir releases “to ensure adequate, minimal water supplies for critical purposes” to the extent “necessary to address the impacts of the drought in the Russian River Watershed”. The Governor later issued drought proclamations on May 10, July 8 and October 19, 2021, but section 7 of his April 21, 2021, proclamation remains in effect. The Governor’s July 8, 2021, Drought Proclamation also suspends CEQA to enable the State Water Board to consider changes to reservoir releases in order to maintain minimum supplies for environmental and human uses. The TUCP’s purpose is to modify the storage thresholds from Lake Pillsbury to Lake Mendocino to be used as the hydrologic index to determine the water supply condition in the Russian River watershed and is within the suspension of CEQA under section 7 of the Governor’s Drought Proclamation.
County Clerks
Mendocino, Sonoma


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