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

The Sonoma County Water Agency is seeking approval from the State Water Resources Control Board to temporarily adjust the hydrologic index used to determine water supply conditions and minimum instream flow requirements in the Russian River watershed, replacing the current metric—cumulative inflow into Lake Pillsbury—with storage levels in Lake Mendocino. This change is urgently needed due to the substantial reduction in potential water imports from the Eel River via PG&E’s Potter Valley Hydroelectric Project, which has disrupted historical water supply patterns. Without this adjustment, mandated water releases from Lake Mendocino and Lake Sonoma could lead to dangerous depletion of reservoir storage, threatening municipal water supplies for communities and critically impacting the survival of listed salmon species in the Russian River. The proposed modification aligns operational decisions with current hydrologic realities, ensuring more accurate and sustainable reservoir management that balances human water needs with ecological protections under the framework of State Water Board Decision 1610. The petition includes a certified environmental exemption under CEQA Sections 15307 and 15308 to streamline approval, reflecting the urgent and temporary nature of the action. The State Water Resources Control Board is the approving authority, with oversight coordinated through its Division of Water Rights in Sacramento, and the agency contact for the petition is Kenneth Emanuel. The performance area includes the Russian River watershed across Mendocino and Sonoma Counties, where reservoir operations and instream flows will be modified if approved. No financial details, procurement clauses, or federal acquisition regulations apply, as this is a state regulatory petition rather than a contractual procurement.