JS Ranch after the Easement:
Getting to the Heart of Californiaâ€™s Water Use Conflicts
Californiaâ€™s recent lengthy drought has ended, but was another reminder that the stateâ€™s ever-increasing water demands often exceed supplies - and will continue to do so. The drought reinvigorated heated debates about the movement of water through or around the San Joaquin-Sacramento River Delta, highlighting the conflict between the needs of Californiaâ€™s native fish and the stateâ€™s immense agricultural economy.
This same apparent conflict between agriculture and fish can be found on the scale of a single ranch, where grazing cattle and spawning salmon depend on the same water resources. Irrigated pasture is an important commodity in California, as is the salmon fishery. Irrigation water provides summer forage for beef cattle, and the economic sustainability of many ranches is dependent upon this forage. At the same time, the creeks from which irrigation water is drawn may be habitat for native salmon. Such is the case on JS Ranch.
JS Ranch sits within the Cow Creek watershed and supports a spawning population of fall-run Chinook salmon. Historically the watershed also supported spring-run Chinook salmon and Central Valley steelhead. The National Oceanic and Atmospheric Administration has proposed Cow Creek as Critical Habitat for these species (both of which are federally listed as threatened), but summer water temperatures are now unsuitable for them. Through conservation easements, such as the one ALC just established on the JS Ranch, the fall-run population can be maintained, but what can be done to bring back the spring spawners? And how can it be done without negatively affecting cattle production?
The American Land Conservancy, University of California Extension, and JS Ranch are seeking an answer to these questions. Through a grant from the National Fish and Wildlife Foundationâ€™s â€œBring Back the Nativesâ€ program, ALC and its partners are assessing the irrigation system on the JS Ranch to identify water-use inefficiencies.
The goal of the project is to reduce the amount of water needed to produce the same amount of forage for cattle, leaving more water in the streams (thus cooler summer temperatures) for the fish. If the project is successful on JS Ranch the hope is that neighboring ranches will willingly participate as well, so that spring-run Chinook and Central Valley steelhead trout can once again return to the Cow Creek watershed.
These cages were built to prevent cattle from grazing so that grass growth can be measured. The amount of water that infiltrates the soil is also being measured, as is the amount that evaporates.
To determine the total volume of water flowing onto the ranch for irrigation, the amount that is poured onto the pastures, and the amount that moves off the ranch in the same ditch, ALC built three weirs so that accurate measurements could be made. Automated devices record the amount of water crossing over each weir hourly through the irrigation season (April-November). This, along with the measurements of water used by the grasses (see image above), will result in a complete water budget for the ranch. As efficiency measures are implemented, the water savings on the ranch can be quantified.