South Delta Temporary Barriers Project

Agricultural barrier on Old River near Tracy

Agricultural barrier on Old River near Tracy, California. DWR

Water flowing through the Delta supports an important ecosystem and serves as a water supply to 27 million people throughout Northern, Central, and Southern California. Salmon migrate through the estuary to freshwater rivers to spawn and California farmers rely on the Delta water conveyed through the State Water Project and federal Central Valley Project to grow the fruits and vegetables that feed our nation. The South Delta Temporary Barriers Project is a unique program that allows us to protect migrating salmon while delivering water to California’s important farming communities.

As conditions warrant, up to four temporary rock barriers are built across South Delta channels each year and then removed:

  • Fish barrier at the Head of Old River
  • Agricultural barrier at Old River near Tracy
  • Agricultural barrier at Middle River
  • Agricultural barrier at Grant Line Canal

The temporary barriers have been shown to improve water levels and water circulation in the South Delta and improve migration conditions for San Joaquin River salmon. Installation and removal dates are based on conditions of DWR’s U.S. Army Corps of Engineers 404 Permit, the California Department of Fish and Wildlife 1601 Permit, other regulatory permits, and various Temporary Entry Permits required from landowners and local reclamation districts.

Fish barrier located at the head of Old River.

Fish barrier located at the head of Old River. DWR

Installation of the barriers allows us to monitor potential effects on south Delta channels and biological effects on vegetation and fisheries within the South Delta. The data is used to help develop agricultural water supply solutions and improve salmon migration. The research allows us to improve structure designs and review alternative timing of operations for structures or “gates,” like those that are a part of the South Delta Improvements Program (SDIP).

This project satisfies the conditions outlined in the agreement between the South Delta Water Agency, the U.S. Bureau of Reclamation, and DWR. Our goal is to provide adequate water levels for South Delta water users so that agricultural activities can continue without interruption.

Temporary Barriers Boat Portage Hours

The Head of  Old River and Middle River Barriers prevent boaters from passing when installed, but portage is available at the other barriers.  After closure boaters with v-hull boats 25 feet or less can utilize the portage facilities provided at the Old River near Tracy and Grant Line Canal Barriers during the times listed below. Boat tenders utilize a universal trailer to move boats over the barrier, and the service is free of charge.

    Mon  Tue  Wed  Thru  Fri  Sat  Sun 
Old River at Tracy  8 am to 6 pm  8 am to 6 pm  8 am to 6 pm  8 am to 6 pm  8 am to 6 pm  7 am to 7 pm 7 am to 7 pm   
Grant Line Canal  6 am to 8 pm  6 am to 8 pm  6 am to 8 pm  6 am to 8 pm  6 am to 8 pm  6 am to 8 pm 6 am to 8 pm   


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Contact Information

Bill McLaughlin
Division of Operations and Maintenance
South Delta Branch
Temporary Barriers and Lower San Joaquin
1516 Ninth Street
Sacramento, CA 95816
Phone: (916) 902-9899