Benefit-cost model for an artificial recharge scenario in the San Joaquin Valley, California

A competitive irrigated agriculture in the San Joaquin Valley of California , under semiarid to arid climate and repetitive drought conditions, relies on groundwater resources to a great extent. As a result of rapid agricultur al development and intense operation of ground water resources over the yea rs, the Valley has been exposed to severe land subsidence and pesticide and fertilizer induced ground water contamination problems. In this paper, bas ed on historical drought recurrences in the region, a model of aridity quan tification and climatic scenario for the period 2000-2030 is described. Mor eover, a schematic economics model is set up to analyze the potential benef its from artificially recharging the underlying aquifer nearby the San Joaq uin River, as compared to the ongoing management plans in the Valley. The a pproach presented in this paper is based on cost assessment simulation and employs weighting coefficients instead of marketing prices. For the climati c scenario considered in this paper, the comparative benefit-cost analysis reveals significant benefits from artificially recharging the aquifer adjac ent to the San Joaquin River.