Development, calibration, and application of an integrated hydrologic model for the Butte Valley Groundwater Basin, California

Abstract:

Recent droughts and increasing population have put substantial stress on California water resources, leading to the passing of the Sustainable Groundwater Management Act (SGMA)—the first legislation to address the connection between ground and surface-water and the need for groundwater management at a local scale. This research presents the development, calibration, and application of an integrated hydrologic model developed for Butte Valley, California, that simulates hydrologic connections in an irrigated agricultural basin. The integrated hydrologic model loosely couples a root zone water budget model and a surface water model into a groundwater model for a sufficient understanding of all hydrologic cycle components required before determining future sustainable management decisions required by SGMA. Multiple sensitivity analyses and calibration methods provide a justified approach to identify model parameters across the global parameter space The calibrated model is then used to evaluate prediction uncertainty of three separate future climate and land-use management scenarios designed to avoid regional water table overdraft. Here we present preliminary model results of the Butte Valley Groundwater Basin used to determine minimum thresholds to future water management decisions in the basin.