Monitoring Flows and Temperatures
Salmon rely on water flow rates to know when and where to spawn and when to migrate out to the Pacific Ocean. We work with our partners in a number of ways to monitor flows and temperatures, while also helping to install protection measures to prevent fish from taking wayward journeys into irrigation canals and ditches.
Fish Monitoring in GCID’s Bypass Channel
This GCID bypass channel is ideal for the use of rotary screw traps due to its concentrated geometry allowing for consistent velocities and the capture of various fish species.
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The sampling is conducted using an eight-foot rotary screw trap (RST), with a live box, in the center of GCID’s bypass channel that is approximately 68-feet wide at the trap site. The site is approximately 300 feet downstream from the fish screen structure and 100 feet downstream of the water control structure. The RST is anchored by secured steel tower structures on opposite banks of the channel and connected by a high-line stainless steel cable suspended above the bypass channel, with an additional cable that is attached directly to the RST. This configuration provides stability and allows the RST to be operated during fluctuating flows throughout the year, especially during the winter months.
The RST is in operation 24-hours a day, seven days a week except during periods of high flows, heavy debris, or in the peak of emigrating Coleman released fish.
To minimize the stress on captured fish and to prevent potential mortalities, the trap is checked a minimum of twice a day for fish and maintained daily. The RST is cleared of debris multiple times a day, depending on the debris present and observed in the bypass channel. There is a year-round on-site night crew and night checks take place regularly, particularly after any sign of precipitation.
What data is collected at the fish trap?
Data collected during each RST check covers a broad range of information such as mean cone revolutions per minute (rpm), water temperature (F), and a water sample to determine the turbidity at the time of service. Daily fish catches are identified to species, counted, and classified by race using size-at-time criteria developed by Frank Fisher’s (CDFW) race designation chart.
Shasta Lake and Keswick Reservoir Flow and Temperature Modeling
Drought and associated impacts on fish species have increased attention on water temperature management in the Sacramento River below Keswick Dam. Shasta Lake and Keswick Reservoir are significant water and hydroelectric resources in California. During times of drought, it is crucial to use these resources effectively.
To make well-informed and balanced decisions on water use, SRSC works to provide accurate information to all stakeholders. The Shasta Lake and Keswick Reservoir Flow and Temperature Modeling Report provides science-based models that are broadly accepted, frequently updated, well-documented and actively supported.
Sacramento River Channel Gradient Restoration Facility
Glenn-Colusa Irrigation District filled and graded parts of the Sacramento River bed and added a rock slope projection to help ensure fish-friendly flow conditions by emulating natural riffles on the riverbed and achieve efficient screen operation by restoring and maintaining the original water surface elevations at the fish screen.
Fish Screens at Hamilton City
In partnership with the U.S. Bureau of Reclamation, GCID constructed fish screens at its Hamilton City pump station off the Sacramento River. As part of that project, the U.S. Army Corps of Engineers built a gradient facility on the main stem to stabilize the river channel and surface water elevations to ensure safe fish passage. Meeting the habitat needs of local wildlife while still ensuring water supply to the region is the cornerstone of GCID’s stewardship mission.