Quoted from: https://ascelibrary.org/doi/abs/10.1061/%28ASCE%29WR.1943-5452.0000089 

The California Department of Water Resources (DWR) and U.S. Bureau of Reclamation Mid-Pacific Region (Reclamation) have developed a rapid, interactive screening model, named CalLite, for evaluating various Central Valley water management options. The CalLite model is being used as a computer-aided negotiations tool in a variety of stakeholder’s processes for improved understanding of water system operations and consensus-based decision making. CalLite was developed using the GoldSim system dynamics software that enables simulation of complex process through a buildup of simple object relationships, incorporates Monte Carlo stochastic methods, and includes dynamic, interactive user interfaces. The screening tool models much of the Central Valley of California that contributes flow to the Delta. The geographical coverage includes the Upper Trinity River, the Sacramento River Valley, the San Joaquin River Valley, the Sacramento–San Joaquin Delta, and the Central Valley Project and the State Water Project service areas. The model allows interactive modification of a variety of water management actions including alternative conveyance options, off-stream storage reservoirs, groundwater management programs, demand management, and Delta channel flow and salinity targets. While CalLite maintains the hydrologic, operational, and institution integrity as represented in the companion model CalSim, very detailed simulation model of the California Water Resources system, also developed and maintained by DWR and Reclamation. The CalLite is easy to use and reduces run time significantly. The simulation results obtained from a typical CalLite run are within 5% of a corresponding CalSim run while run time is less than 5 min compared to 30 min for a corresponding CalSim run.