MONO LAKE C O M M I T T E E P. O . B o x 2 9 Hwy 395 and Third Street Lee Vining, CA 93541 Phone (760) 647-6595 Fax (760) 647-6377
Board of Directors Chair: Sally Gaines Martha Davis Vireo Gaines David Kanner Gina Radieve To m S o t o S h e r r y l Ta y l o r Doug Virtue Kristine Zeigler
Directors Emeriti Ed Grosswiler Richard Lehman
Executive Director Geoffrey McQuilkin
Southern California Office 1718 Wellesley Ave Los Angeles, CA 90025-3634
On the Internet monolake.org monobasinresearch.org
April 15, 2025 Erik Ekdahl Deputy Director, Division of Water Rights State Water Resources Control Board Sent via email RE: Mitigation of malfunctioning LADWP rotovalve impacts on Rush Creek Dear Mr. Ekdahl, Malfunctioning Los Angeles Department of Water and Power (LADWP) infrastructure at Grant Lake Reservoir is preventing LADWP from complying with State Water Resources Control Board license conditions designed to restore the trout fishery, riparian resources, and geomorphology of Rush Creek, which were extensively damaged by decades of excessive water diversion by LADWP. The Mono Lake Committee (MLC) proposes interim reservoir management requirements designed to mitigate the Stream Ecosystem Flow impairment caused by the malfunctioning valve by maximizing the potential for reservoir spill. This proposal is discussed below and provided in detail in Appendix A. In 2024, the State Water Board issued an Order approving Temporary Urgency Changes to the Stream Ecosystem Flows because LADWP infrastructure at Grant Lake Reservoir “currently has a malfunctioning outlet valve, referred to as the rotovalve, that can no longer be safely operated to release flows higher than 175 cfs.” Due to the damaged rotovalve, LADWP plans to submit a Temporary Urgency Change Petition (TUCP) request again in 2025. In fact, based on the repair timeline in LADWP’s December 30, 2024, report on the Grant Lake Reservoir Outlet, LADWP can be expected to submit TUCPs in 2026, 2027, 2028, 2029, 2030, and quite possibly additional years after that. Waiving Stream Ecosystem Flow requirements for seven or more years is a substantial departure from the restoration program for Rush Creek, creating unreasonable effects on the program and the fish, wildlife, and instream resources. While the failing infrastructure is of understandable concern, it is in the public interest to take all reasonable steps to reduce the negative impact of this situation on the restoration of Rush Creek and the health of the fishery and habitat. With due diligence LADWP can anticipate and mitigate its multi-year inability to meet the Stream Ecosystem Flow requirements, in particular its impairment of the peak flow releases. Mitigation of malfunctioning LADWP rotovalve impacts on Rush Creek | April 15, 2025 | page 1