A question fish biologists are often asked is “how much water do fish need?”
One of the major factors affecting the decline of salmonids in California is insufficient streamflow. Streamflow controls so many different aspects of the aquatic environment such as habitat-forming processes for salmonids and other native fishes.
It also cues specific life history events such as juvenile and adult fish migrations, behavior, and, more recently, has been shown to influence the relative success of introduced or invasive species.
Changes in streamflow can also strongly affect water quality, including temperature, but also aquatic food webs.
CalTrout is studying environmental flows and using innovative strategies to find out how much water fish need to ensure thriving populations and also balance the needs of people.
The California Environmental Flows Framework (CEFF) seeks to determine ecological flow criteria for native fishes and other aquatic species throughout the state, which can be used to inform the development of environmental flow prescriptions.Read more
Cardoza Ranch Flow Enhancement Project
The Cardoza Ranch Flow Enhancement Project in the Shasta Valley is a collaborative project with a fifth-generation ranching family to help increase irrigation efficiencies across their property while at the same time removing a fish barrier that the will result in 14 miles of unimpeded fish passage and access to important Chinook and coho salmon rearing and spawning habitat.
Little Shasta Hart Ranch Flow Enhancement Project
The Hart Ranch Project on Little Shasta River is working to bring salmon back to a section of stream where they have long since disappeared due to irrigation diversions and water obstructions. By working with the landowners, multi-generation ranchers, CalTrout provides incentives to improve water use efficiency and habitat conditions while reducing the regulatory burden and liability under the Endangered Species Act.
This Safe Harbor Agreement is resulting in permanent dedication of 1.5 cubic feet per second of cold water into the Little Shasta River when coho salmon need it most.