This project provided technical assistance, environmental permitting, and compliance support for the physical modification of the Eastside Bypass Control Structure (EBCS) on the San Joaquin River in Merced County — a gated flood control structure identified as a significant low-flow passage barrier within the San Joaquin River Restoration Program’s Restoration Area. By funding the renewal and completion of required environmental compliance documents, the project is enabling construction of a 380-foot engineered rock ramp and structural modifications to the EBCS that will improve migration conditions for spring-run Chinook salmon, steelhead, White Sturgeon, Green Sturgeon, and Pacific lamprey.
Location: The Eastside Bypass Control Structure (EBCS) is located on the Eastside Bypass flood control channel in Merced County, within Reach 5 of the San Joaquin River Restoration Program (SJRRP) Restoration Area. The SJRRP Restoration Area spans the San Joaquin River from Friant Dam downstream to the confluence with the Merced River near Hills Ferry. The Eastside Bypass serves as a critical fish migration corridor connecting the mainstem San Joaquin River with upper restoration reaches and the Merced National Wildlife Refuge.
Historical Fish Presence: The San Joaquin River historically supported substantial runs of spring-run Chinook salmon (O. tshawytscha), steelhead (O. mykiss), White Sturgeon (A. transmontanus), the threatened southern distinct population segment of Green Sturgeon (A. medirostris), and Pacific lamprey (Entosphenus tridentatus). Construction of Friant Dam in 1942 and subsequent water diversions eliminated salmon from over 60 miles of river channel above the Merced River confluence for more than six decades. The SJRRP documented its first returning adult spring-run Chinook in 2019, marking a significant recovery milestone. White and Green Sturgeon have been documented using the Restoration Area, with a female White Sturgeon detected 7.5 river miles into the RA in January 2023 through the companion LFWO telemetry project. Spring-run Chinook salmon are listed as threatened under the ESA, and Green Sturgeon as threatened.
Project Lead: U.S. Fish and Wildlife Service (USFWS), San Joaquin River Restoration Program
Project Partners: California Department of Water Resources (DWR), San Joaquin River Restoration Program (SJRRP), U.S. Bureau of Reclamation; USFWS Financial Assistance Support and Oversight (FASO) team. This project is closely coordinated with the companion CFPF-funded “Designing for Sturgeon Passage in the San Joaquin River at the Eastside Bypass Control Structure” telemetry project, which generates biological data to inform the EBCS design.
CFPF Funding: $51,440
Project Description: The EBCS is a gated concrete structure that is part of the Lower San Joaquin River Flood Control Project and has been identified as a significant barrier to fish passage at low flows within the SJRRP Restoration Area. The planned improvement project — developed by DWR in coordination with USFWS, USBOR, and the SJRRP — involves removing a portion of the structure’s sill, half of the energy dissipation blocks within the four center bays, and four-foot-high stop logs on the upstream side, combined with construction of an approximately 380-foot full-width rock ramp downstream of the structure. These modifications are designed to allow passage for salmonids while also improving passage for bottom-dwelling native fishes such as sturgeon and lamprey, without compromising the structure’s flood control function. Forum funding supports the technical assistance and environmental compliance work needed to advance the project to construction. During the reporting period (December 2023 – April 2024), USFWS completed regulatory and environmental compliance documents, initiated internal fund obligation and contracting processes, and met with DWR to develop a streamlined path forward including the Statement of Work and budget narrative. A contractor was anticipated to be selected prior to the end of the USFWS fiscal year, at which point permit renewal and compliance activities would begin in earnest. No construction or monitoring activities had occurred within the reporting period.
Expected Completion: Fall 2024
Project Effectiveness: When complete, modifications to the EBCS are projected to allow adult spring-run Chinook salmon and steelhead to enter the lower Eastside Bypass and move into the Middle Eastside Bypass before rejoining the San Joaquin River mainstem, and to allow juvenile salmon migrating downstream to use the Eastside Bypass corridor. The companion USFWS White Sturgeon telemetry project, also funded by the Forum, is designed to evaluate whether sturgeon are able to successfully pass the modified structure following construction.