Yolo Bypass Projects

The Yolo Bypass Salmonid Habitat Restoration and Fish Passage Implementation Plan identified Agricultural Road Crossing 4 as a fish passage impediment. It is an earthen road crossing that spans Tule Canal, just south of where the Sacramento Bypass connects with the Yolo Bypass. The crossing provides the ability to impound water for agricultural and waterfowl purposes. DWR is in the process of developing early conceptual options to improve fish passage through the Tule Canal in the Yolo Bypass. 

Planning and Design Status: Planning for this project is at the conceptual design level.

Anticipated Construction: 2019

DWR and Reclamation have proposed the Fremont Weir Adult Fish Passage Modification Project, which would improve salmonid and sturgeon passage in the Yolo Bypass by:

• Modifying the existing Fremont Weir fish ladder to provide upstream passage when the Sacramento River overtops Fremont Weir and immediately after the river recedes.

• Improving fish passage conditions in the channel that extends from the existing fish ladder upstream to the Sacramento River.

• Improving fish passage conditions in the scour channel the extends from the existing fish ladder downstream to an existing deep pond.

• Removing one earthen agricultural road crossing and replacing one earthen agricultural road crossing with a structure that allows for fish passage through the Tule Canal and continued agricultural utility.

Planning and Design Status: DWR and Reclamation released a draft Initial Study and Environmental Assessment (IS/EA) and proposed Mitigated Negative Declaration (MND) for the proposed Fremont Weir Adult Fish Passage Modification Project for public review in spring and summer of 2017 (State Clearinghouse Number 201702212). A Notice of Determination (NOD) and final IS/EA and MND was filed with the State Clearinghouse in summer of 2017 and all permits were received in summer 2017.

Anticipated Construction: Construction began in fall 2017 and will start again in spring 2018

Modification of Lisbon Weir will be a crucial upgrade for adult migrating fish. Lisbon Weir delays migration in the Yolo Bypass. When the bypass is not flooded, salmon can only pass this rock weir when flood tides open a small section of flap gate or when a strong high tide overtops the weir. This modification project would improve fish passage throughout the tidal cycle while maintaining a reliable agricultural diversion.

Planning and Design Status: Planning for this project is at the conceptual design level.

Where Putah Creek joins and flows through the Yolo Bypass, the project will create a new creek channel that will improve fish passage and native fish habitat, including seasonally flooded wetlands. The project also will connect Putah Creek with previously restored tidal channels along the Toe Drain and widen and enhance those channels. This will create tidal habitat and provide better passage for salmon. Finally, the project will improve fish passage to and from spawning grounds on upper Putah Creek by installing a structure that will better control the seasonal timing and magnitude of creek flows.

Planning and Design Status: The California Department of Fish and Wildlife (CDFW) has previously led the planning effort and CEQA compliance for this project. Currently, DWR has taken the lead in planning this project. Planning for this project is at the conceptual design level.

Anticipated Construction:  2020

Wallace Weir is a water control structure on the Knights Landing Ridge Cut where it enters the west side of the Yolo Bypass. Adult salmon have been found in dead-end agricultural ditches upstream of the weir in the Colusa Basin Drain system, especially when flows in the Knights Landing Ridge Cut are high. The earthen dam, which washes away during high flow events, was replaced with a permanent structure that will prevent migration of salmon and sturgeon into the Colusa Basin Drain. The project also includes a facility to allow for efficient trapping and relocation of fish to the Sacramento River.

Planning and Design Status: DWR worked with Reclamation District (RD) 108 to plan and permit this project. Visit RD 108 Wallace Weir Fish Rescue Facility Page for more information and to download the Initial Study and Mitigated Negative Declaration, which was released in April 2016.

Construction: Construction began in 2016 and will be finished in early 2018.

DWR and Reclamation have developed the Yolo Bypass Salmonid Habitat Restoration and Fish Passage Project to improve fish passage and increase floodplain fisheries rearing habitat in Yolo Bypass and the lower Sacramento River basin.  The Project would primarily consist of a new Fremont Weir headworks structure, a new outlet channel, and downstream channel improvements. Each of these facilities is a component of the three different proposed outlet channel alignments (east, center, and west) in the Yolo Bypass. Each channel alignment would terminate downstream into the existing Tule Pond. Additional alternative-specific features have been identified to further meet the intent of the RPA actions. In addition, to improve fish passage, the project will also include modification to an agricultural road crossing in the Yolo Bypass.

Planning and Design Status: The project is in the alternatives development phase, which includes conceptual engineering, impact analysis, and avoidance and minimization measures. A public draft Environmental Impact Statement/Environmental Impact Report (EIS/EIR) was released in December 2017 and a Final EIS/EIR is expected in late 2018.

Anticipated Construction: 2020 or 2021

Yolo Bypass Salmonid Habitat Restoration and Fish Passage Project Data Viewer:  DWR and Reclamation created the Yolo Bypass Salmonid Habitat Restoration and Fish Passage Project Data Viewer (Data Viewer) as a platform to view modeled results of how increased flows may affect inundation within the Yolo Bypass. The Data Viewer is publicly accessible and provides hydrodynamic modeling results and maps for any selected assessor parcel in the Yolo Bypass.

• Background Information
• How To Guide
• Data Viewer