Estimating Land Use Management Practice Costs to Improve Water Quality, Central Valley, California.

The Central Valley of California has over 30,000 growers irrigating nearly 4 million hectares of land.  Frequently runoff from these operations contains constituents of concern that impact receiving waters.  Water quality monitoring has been increasing in surface and ground water to assist regulatory authorities in implementing limits over discharges to both surface and groundwater.  This paper provides detail of five approaches used to cost alternatives that are being considered to ensure irrigators comply with the Federal Clean Water Act. This analysis quantifies the extent of new management practices and other compliance actions that will be required and the expected economic impacts associated with new regulations.  Lands impacting water quality were determined based on the EPA’s 303d list of impaired waters surface waters, a spatial analysis of land use types in the Central Valley and constituent use by land use type.  Model management practices were developed and applied to affected lands.Administration, monitoring, and planning costs were estimated using information derived from existing local and regional programs.  Results will be presented on a regional basis.