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

Summary

SCH Number
2021110237
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
Received
Posted
11/17/2021
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 (Figure 1). Sonoma Water is filing temporary urgency change petitions (TUCP) requesting that storage thresholds in Lake Mendocino be used as the hydrologic index to determine the water supply condition in the Russian River watershed. These changes are necessary to ensure that the water supply condition and corresponding minimum instream flow requirements in the Russian River watershed are aligned with actual watershed hydrologic conditions. This is essential to maintain sustainable reservoir/river operations to protect municipal water supply and listed salmon species in the Russian River. In Sonoma Water’s water right permits established under State Water Board’s Decision 1610, the water supply condition for the Russian River is determined using cumulative inflow into Lake Pillsbury as the hydrologic index. Lake Pillsbury is a storage reservoir located in the Eel River watershed for Pacific Gas & Electric Company’s (PG&E) Potter Valley Hydroelectric Project (PVP) which transfers water into the East Fork of the Russian River. PG&E has informed Sonoma Water that the transformer bank at the PVP powerhouse failed and will need to be replaced in order to convey water through the powerhouse for power generation. PG&E estimates it will take up to two years to replace the transformer bank at a cost of five to ten million dollars. It is highly uncertain whether PG&E will make the necessary repairs to continue power generation as its Federal Energy Regulatory Commission (FERC) operating license expires in April 2022. In January 2019, PG&E withdrew its Preliminary Application Document and Notice of Intent to relicense the project. Currently, the PVP is rated at a flow rate up to 240 cubic feet per second (cfs) through the powerhouse for power generation. PG&E can bypass the powerhouse at flow rates up to 135 cfs to meet FERC license requirements for minimum instream releases into the East Branch Russian River and water supply contract requirements with the Potter Valley Irrigation District (PVID). PG&E’s transfer obligations to meet FERC license requirements and PVID contract amounts until April 14 is 45 cfs. PG&E has indicated that, without the ability to generate hydropower, it is unlikely PG&E will make discretionary transfers of Eel River water through the PVP above its license and contract obligations. Discretionary transfers to generate hydropower can occur up until early April if hydrologic conditions on the Eel River and at Lake Pillsbury are being met. Without the discretionary transfer of Eel River water to generate hydropower, the total transfer through the PVP will be reduced by up to 400 acre-feet per day. Under these operating conditions of the PVP, the influence of the Eel River water imports on downstream hydrologic conditions in the Russian River will be greatly diminished. Therefore, there will be little to no correlation between cumulative inflow into Lake Pillsbury and the hydrologic conditions in the Russian River watershed. In addition, current drought conditions continue to deplete storage in Lake Mendocino and Lake Sonoma. As of November 15, 2021, the water supply storage level in Lake Mendocino was 19,995 acre-feet (AF). This storage level is approximately 29 percent of the available water conservation pool for this time of year. This is the second lowest storage level for this time of year since Lake Mendocino filled in 1959. As of November 15, 2021 the water supply storage level in Lake Sonoma was 122,322 acre-feet. This storage level is approximately 50 percent of the available water conservation pool. This is the lowest storage level for this time of year since Lake Sonoma filled in 1986. Consequently, Sonoma Water is requesting the State Water Board approve TUCPs that uses storage thresholds in Lake Mendocino as the hydrologic index to determine the water supply condition in the Russian River watershed.

Contact Information

Name
Jessica Martini-Lamb
Agency Name
Sonoma County Water Agency Environmental Resources Manager
Contact Types
Lead/Public Agency / Project Applicant / Parties Undertaking Project

Location

Cities
Cloverdale, Healdsburg, Ukiah
Counties
Mendocino, Sonoma
Regions
Citywide, Countywide, Northern California
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.

Notice of Exemption

Exempt Status
Categorical Exemption
Type, Section or Code
State CEQA Guidelines 15307; State CEQA Guidelines 15308; Section 21080(b)(4);15269(c) and 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. These emergency conditions also are demonstrated by Governor Newsom’s April 21, 2021 proclamation of a drought emergency in Sonoma and Mendocino Counties due to drought conditions in the Russian River Watershed (Governor’s Drought Proclamation). Section 7 of the Governor’s Drought Proclamation suspends the requirements of CEQA for purposes of the State Water Board’s consideration of modifying reservoir releases based on a representative hydrologic index, which would be a necessary element of an order granting the TUCP. The Governor has continued that proclamation for Sonoma and Mendocino Counties through further drought proclamations on May 10, July 8 and October 19, 2021. In addition, the Sonoma County Board of Supervisors on April 27, 2021, proclaimed a local emergency due to drought conditions in the Sonoma County Operational Area (most recently continued on November 2, 2021) and the Mendocino County Board of Supervisors April 20, 2021, adopted a resolution declaring a local emergency and imminent threat of disaster in Mendocino County due to drought conditions. 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 2020 and 2021. Approval of the TUCP 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 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.” The Governor later issued drought proclamations on May 10, July 8 and October 19, 2021, but section 7 of his April 21 proclamation remains in effect. 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

Attachments

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