Title
Consider receiving an update on implementation of the Interim Operations Plan for San Antonio and Nacimiento Reservoirs and adopt a revised passage flow target for steelhead migration in the Salinas River. (Staff: Peter Kwiek)
Report
SUMMARY
On November 21, 2022, the Monterey County Water Resources Agency Board of Directors (BOD) adopted the Interim Operations Plan (IOP) for Nacimiento and San Antonio Reservoirs to address specific conditions where the Flow Prescription did not meet its intended goals over the first 13 years of Salinas Valley Water Project operation. The IOP was implemented beginning in 2023, but natural flows (2023 and 2024) and Flow Prescription triggered actions (2025) obviated the need for IOP support to meet Flow Prescription passage targets in the first three years of implementation.
In February of 2025, a release action based on Flow Prescription triggers provided an opportunity to test and verify a new steelhead migration flow threshold determined in a recent critical riffle study conducted in support of the development of the Habitat Conservation Plan.
The IOP has provided supplemental adaptive management to the existing Flow Prescription while the Salinas River Operations Habitat Conservation Plan (HCP) is under development.
Staff finds that the IOP continues to provide a flexible and effective mechanism to address shortcomings of the Flow prescription. Hydrologic conditions have effectively precluded the need for IOP actions since adoption. Staff recommends continuation of IOP implementation with modification of the steelhead migration flow target.
DISCUSSION:
IOP Development and Adoption
The Salinas Valley Water Project Flow Prescription for Steelhead Trout in the Salinas River (Flow Prescription), was incorporated into water rights licenses 7543 and 12624, and Permit 21089. It targets providing steelhead migration to and from the lower Salinas River Basin, which includes the Arroyo Seco and the lower Nacimiento River, an...
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