Climate Driven Water Resources Model of the Sacramento Basin, California

Abstract

A climate-driven water resource model of California’s Sacramento River Basin (SACB) is presented, based on the Water Evaluation and Planning model Version 21 (WEAP21). The model’s configuration, calibration, testing, and limitations are presented. The major contribution includes an integration of the watershed’s surface and subsurface hydrology, consumptive, and nonconsumptive use, and the water management infrastructure and controls that determine how water naturally flows and is managed. The SACB was subdivided into numerous catchments; groundwater basins; irrigated areas; urban/export use; environmental requirements; and canals, diversions, and reservoirs in an attempt to characterize the forces that act on water throughout the basin. A monthly climate time series forced an embedded hydrologic model that simulates runoff, groundwater-surface water interactions, and consumptive agriculture and urban water uses. Results show that the model can reproduce both local and regional water balances, including managed and unmanaged streamflow, reservoir storage, agriculture and urban water uses, and the allocation of ground water and surface water supplies, which should be useful for various California water planning processes.