Rapid, Interactive Screening Model for California Water Management

California is experiencing unprecedented pressures on its water resources and water infrastructure. Various state, federal, and regional planning processes are considering significant changes to California water management to improve water supply reliability, protect fisheries and enhance ecosystems, and improve water quality. To help meet the needs of these programs, U.S. Bureau of Reclamation (Reclamation) and the California Department of Water Resources (DWR) have developed CalLite, a rapid, interactive screening model for Central Valley water management. CalLite simulates the hydrology of the Central Valley, reservoir operations, project operations and delivery allocation decisions, Delta salinity responses to river flow and export changes, and habitat-ecosystem indices. CalLite simulates water conditions in the Central Valley over an 82-yr planning period in under 5 minutes and allows interactive modification of a variety of water management actions including new conveyance facilities, offstream storage reservoirs, groundwater management programs, demand management, and river and Delta channel flow and salinity targets. In addition, CalLite can simulate observed or possible future hydrologic regimes to represent climate change impacts. The screening tool is designed for use in a variety of stakeholder processes for improved understanding of water system operations and future management. CalLite serves a unique purpose in California water management. The tool bridges the gap between more detailed system models managed by DWR and Reclamation and policy/stakeholder demand for rapid and interactive policy evaluations. CalLite will be applied to assist in the screening of a variety water management options and to educate decision makers on system responses.