Response of Groundwater, Soil, and Surface Water Systems to Land Retirement in the Central Valley of California
Thousands of acres of drainage impacted farmland are being retired from irrigated agriculture in the western San Joaquin Valley, California. These lands are underlain by poorly drained soils and shallow, saline ground water with high concentrations of selenium and boron that pose potential toxic risk to plants and wildlife. This research will provide a basis for quantifying ecologic risk on retired farmland by measuring changes in salinity, selenium, and boron concentrations in soils and ground water at two demonstration project sites in the Central Valley. Results will be used to guide future ecological restoration and land management decisions for retired lands.
Need and Benefit
Thousands of acres of irrigated agricultural lands are impacted by severe drainage problems in the Central Valley. These lands are underlain by poorly drained soils and shallow ground water with elevated concentrations of selenium, boron, and high salinity. Land Retirement is the removal of these lands from irrigated agricultural production as one means to mitigate the drainage problem. The Land Retirement program is being implemented under the authority of the Central Valley Project Improvement Act (CVPIA) by an inter-agency team with representatives from Reclamation, Bureau of Land Management (BLM), and the U.S. Fish and Wildlife Service (USFWS). The goals of the land retirement program are to:
* Provide drainage source reduction
* Create upland wildlife habitat
* Acquire CVP water associated with the retired lands when feasible
In order to assess the environmental impacts of land retirement, a five-year, 15,000 acre demonstration project is being implemented at two sites in Fresno, Kings, and Tulare Counties, California. The data from the demonstration project will be utilized to verify or refute conceptual and numerical models of land retirement and to guide future decisions regarding ecological restoration and management of retired lands. Data from research to date indicate declining shallow ground water levels as well as elevated salt, selenium, and boron levels in project soils and ground water. Soil and ground water salinity, selenium and boron content are of concern due to potential toxicity to wildlife and plants. Soil salinity, selenium, and boron concentrations will be measured over the five-year demonstration project to detect changes in soil and ground water conditions that may result from land retirement.
Contact the Principal Investigator for information about these documents.