Cow Creek - Bassett Diversion Fish Passage Project

Eastside Region

Bassett Diversion Fish Passage Project

  • Location: Cow Creek Watershed, Shasta County
  • Project Sponsor: Cow Creek Watershed Group, Western Shasta RCD
  • Time Frame: 2007–2009
  • Cost: $100,000 (CALFED Watershed Program, DFG)
  • Project Objectives:
    • Prevent fish stranding in irrigation delivery canals
    • Improve irrigation water diversion capabilities
    • Improve passage of anadromous fish past the diversion dam

Cow Creek is one of the Sacramento River Basin’s priority watersheds for natural spawning of Chinook salmon and steelhead. The stream also is heavily used for irrigation agriculture, and there are a number of irrigation diversion dams that historically have been problematic for successful passage, spawning, and rearing of anadromous fish. The Bassett Diversion Fish Passage Project is located on Old Cow Creek (one of five main branches of Cow Creek) about 20 miles east of Palo Cedro. The existing diversion structure includes a concrete dam with flashboards installed during the irrigation season. This project involved two phases. Phase I was the installation of a new intake structure at the dam where water is diverted into the head of the Bassett Canal. The new intake structure included fish screening facilities to prevent fish stranding in the canal and on irrigated fields. Phase II was the construction of a side channel on the south side of the diversion dam that allows anadromous fish to pass beyond the dam to access upstream spawning habitat.

The Bassett Canal water intake structure included a state-of-the-art fish screen with automated cleaning capability. Fish that enter the canal intake structure and become blocked by the screen mechanism are directed back into Cow Creek through a newly constructed side chute. Assistance on project design and construction was provided by DFG fish screen personnel in Redding. The side channel in Cow Creek used to route upstream migrating fish beyond the diversion dam was enhanced by construction of a berm between the main creek channel and the side channel and excavation of the side channel at a proper elevation to allow water flow and fish passage above and below the dam.

In addition to completion of the Bassett Diversion improvements, Cow Creek Watershed Group and Western Shasta RCD have implemented similar improvements on the Woodman Diversion on North Cow Creek and have completed feasibility and design studies on the Millville Diversion on Clover Creek. Concurrent with the diversion structure improvements, the watershed group and RCD have completed a feasibility report and are seeking funding for improvements on several major canals to improve water use efficiency and enhance instream flow in Cow Creek.