The Los Angeles River Fish Passage & Habitat Structures Design Project
The Los Angeles River Fish Passage and Habitat Structures Design (LAR FPHS) Project examines potential ways to redesign the channel bed and banks in a 4.8-mile section of the Los Angeles River in the downtown city area. This pilot project aims to provide increased flow complexity and habitat heterogeneity within a confined urban stretch of the Los Angeles River mainstem channel to enhance steelhead fish passage and migration corridors to upper tributaries (e.g., Arroyo Seco, Tujunga Creek, and others).
The LAR FPHS Project is a multi-agency partnership effort funded by the State of California Wildlife Conservation Board (WCB) under a Proposition 68 Restoration Grant for Wildlife Corridors and Fish Passage Program. The Project is led by the Council for Watershed Health (CWH), City of Los Angeles, and Stillwater Sciences in coordination with other partners and government agencies, including the U.S. Bureau of Reclamation (Reclamation), Southern California Coastal Water Research Project (SCCWRP), National Marine Fisheries Service (NMFS), U.S. Army Corps of Engineers (USACE), County of Los Angeles, California Department of Fish and Wildlife (CDFW), U.S. Fish and Wildlife Service (USFWS), Regional Water Quality Control Board (RWQCB), Arroyo Seco Foundation (ASF), and Friends of the Los Angeles River (FoLAR).
Steelhead was once a common species in the Los Angeles River Watershed until the 1940s when steelhead populations drastically decreased due to the impact of excessive recreational fishing, loss and modification of freshwater habitat, and the presence of man-made physical structures and barriers.
It would take approximately 2–3 days for an adult steelhead to travel 20 miles, from the mouth of the Los Angeles River in Long Beach, to the Fish Passage & Habitat Structures project site near Boyle Heights, Los Angeles
The main objective of the LAR FPHS Project is to conduct science-based research and design (Basis of Design Report to 60% design drawings, CEQA, and initial permitting) of fish passage and habitat structures that address limiting factors for steelhead and other native fish within a 4.8-mile section of the concrete-lined Los Angeles River through Downtown Los Angeles. The Project provides opportunities to address watershed-wide data gaps. In turn, this information can be used to fill these gaps and to support future projects aimed to enhance steelhead recovery throughout the LARW, and to identify other potential suitable sites for fish passage projects across the Los Angeles River and its upper tributaries.
SCOPE & STATUS
How is the “project design” being funded?
The Wildlife Conservation Board has funded this project under a State of California Prop. 68 Fish Passage grant (WC-1922DC) in the amount of $1.356M. The City and other partners, including Stillwater Sciences, SCCWRP, ASF, and FoLAR, are providing in-kind services as matching funds for the project. Future phases of the project will include 100% design, permitting, and construction.
How will “implementation” of the project be funded?
The full cost to implement the project has not yet been determined. The project proponents will work with the associated agencies and additional partners to identify funding to fully implement the project.
Who is responsible for operations and maintenance?
The project is being designed to be self-cleaning by mimicking natural stream morphology, with natural flushing of sediment by hydraulic processes. Habitat structures would be anchored in place to maintain channel stability and protection of existing infrastructure. Flood-related requirements must be met in order for the project to be constructed. The City, County, and USACE are discussing operations and maintenance roles and responsibilities for the project. Maintenance responsibilities would be similar to what they are now, which is minimal in this concrete-lined reach of the channel. However, future project maintenance costs, if any, would be funded through a cooperative agreement with the project partners.
What type of monitoring is required?
Monitoring includes assessment of structural stability of the structures, biological surveys (specific to steelhead and other native fish as well as invasive species), and physical habitat conditions.
Does the project impact water supplies?
No. The LAR FPHS project is consistent with the California State Water Resources Control Board (SWRCB)’s LA River Environmental Flows Study (EFS) that is currently underway. As project partner, SCCWRP is working on the modeling and steelhead/rainbow trout species criteria for the Los Angeles River in collaboration with Stillwater Sciences. Steelhead are one of many target species considered in SCCWRP’s hydrologic and hydraulic modeling for the Los Angeles River. Since the LAR FPHS project is focused on migratory periods, meaning when adult steelhead move at the tail-end of a winter storm, no additional water is needed to support migration. LA Department of Water and Power, among other water utilities, is involved in the study to address integrated water management objectives (water quality, water reuse, recycling, and other water supply/management objectives). The design does consider low-flow conditions for fish to move upstream and downstream. These flows are also consistent with the SWRCB LA River EFS.
For more information please reach out to the LAR FPHS Project Manager, Andrea Dell’Apa firstname.lastname@example.org or 213-229-9945 - ext.5.
- Project Profile [PDF]
Q&A Fact Sheet [PDF]
Final Techical Memorandum: Conceptual Ecological Model and Limiting Factors Analysis for Steelhead in the Los Angeles River Watershed, September 2020