A climate-change impact analysis was completed for a confidential client in California. The purpose of the study was to provide climate-impacted hydrology (streamflow, irrigation water demand) for a future planning horizon. Our team provided a low-cost solution by utilizing existing Bureau of Reclamation (USBR) Coupled Model Intercomparison Project (CMIP5) climate change runs processed through the Variable Infiltration Capacity (VIC) hydrologic model. The future climate-impacted hydrology from 2020-2049 (streamflow, evapotranspiration) was compared to a baseline hydrology from 1970-1999, to determine a monthly set of “change factors” for water supply and water demand (streamflow and irrigation water demand, respectively). The change factors were applied to the historical hydrology datasets to create climate-adjusted timeseries for streamflow and water demand, which were used to evaluate future water supply conditions.