GSFLOW model to evaluate the effect of groundwater pumpage and climate stresses on the integrated hydrologic system of the Yucaipa subbasin, Yucaipa Valley watershed, San Bernardino and Riverside Counties, California.

A three-dimensional, GSFLOW model was developed to simulate and quantify the hydrologic system of the Yucaipa subbasin. The model was calibrated to conditions from 1970 to 2014, the period for which data are most complete and reliable. The model was used to (1) quantify the effects of historical and potential water-resource development induced by climate changes and human-related activities, and (2) to derive components of the daily water budgets for the components of the integrated model for calendar years 1970–2014 (long-term average), with particular attention given to groundwater budgets for dry and wet periods. The model also was used to assess the effects of pumping and climate stresses on hydrologic-budget components in 12 groundwater [...]