Instream Flow Analysis – Big Sur River
The precipitous decline of salmon and steelhead populations throughout the state of California is attributed to numerous factors, some of which include; water supply, water quality, habitat destruction, and blockages to fish migrations. The instream flow projects are designed to look at one aspect of the myriad of issues plaguing salmon populations, water quantity. There are three instream flow projects the OPC approved statewide, they include; the Shasta River, the Big Sur, and the Santa Marina River.
Each of the rivers were chosen based on a list of twenty-two priority streams that require instream flow analysis throughout the state. (This list is exhibit 2 of the staff recommendation, linked below).
This list was developed with input from regional DFG staff, water board staff, U.S. Fish and Wildlife Service, and NOAA national marine fisheries service.
In developing the list of priority rivers, DFG staff considered criteria such as; 1) presence of anadromous species, 2) likelihood that DFG flow recommendations would provide a high level of improvement, 3) availability of recent flow studies or other relevant data, and 4) the possibility of partners and willing landowners to work with staff on these assessments.
Completion of these projects satisfies many goals and priorities for the OPC, including the goal to significantly improve the quantity and quality of ocean and coastal habitat in California, specifically to work toward monitoring and measuring stream flows on key coastal streams as well as to determine the flow rates necessary to protect water quality in coastal lagoons and estuaries.
For the Big Sur River, the OPC funds will be used to focus on the estuary portion of the river. The rest of the river will be analyzed by DFG staff and The Pacific Marine Fisheries Commission (PSMFC). For the estuary component, PSMFC will conduct bathymetric mapping to track potential changes in water volume and to assess seasonal or annual changes in major water quality parameters such as; temperature, nitrogen, phosphorus, salinity and acidity. Major tasks of the study will include; water flow will be monitored to track effects of inflows, tides, sand barrier closures on estuary volume and fish sampling to detect populations. The completion of all the projects will aim to provide an increase in habitat for salmonids.
The OPC has approved a grant to Pacific States Marine Fisheries Commission for $100,000
Events & Updates
None at this time.
The research gained from this project will help identify the quantity of water, what temperature, and flow that is required for salmon and steelhead species to properly mature in freshwater environs. The data gathered will hopefully lead to an increase in available habitat and water supply for these endangered species.
The result of the instream flow analysis will be provided to the State Water Resources Control Board by the Department of Fish and Game in the form of flow recommendations for the Big Sur River.