Central Valley models and tools

The California Department of Water Resources (DWR) develops and uses a number of modeling tools to support water management Statewide and in the Central Valley. Among these tools are the CalSim 2, CalLite, C2VSim,SVSim, CVFED, and CVHS. CalSim is the model used to simulate California State Water Project (SWP)/Central Valley Project (CVP) operations. CalLite is an interactive screening model for evaluating various Central Valley water management alternatives. C2VSim is computer program that simulates water movement through the linked land surface, groundwater and surface water flow systems in California’s Central Valley. SVSim is an application of the Integrated Water Flow Model (IWFM) numerical code and is based on DWR’s C2VSim model, whichprovides an updated analysis of geologic and hydrogeologic data for the Sacramento Valley.  
CalSim 3 is a new and improved water resources planning model, jointly developed by the California Department of Water Resources (DWR) and the Mid-Pacific Region of the U.S. Bureau of Reclamation (Reclamation), to simulate operations of the State Water Project (SWP) and the Central Valley Project (CVP) and much of the water resources infrastructure in the Central Valley of California and the Sacramento-San Joaquin Delta region. It is the next generation of CalSim-II model which has been used in various Central Valley water resources planning studies since its release in 2002. 

Major improvements and enhancements in CalSim 3.0 include:

  Finer model spatial resolution
  Better water supply and demand estimation
  Improved groundwater representation and simulation
  Enhanced model validation
  Extended model spatial and temporal domain
  Advanced model engine (WRIMS 2.0)
  Thorough model documentation
  Model supporting tools
The Water Resource Integrated Modeling System (WRIMS model engine or WRIMS) (formally named CALSIM) is a generalized water resources modeling system for evaluating operational alternatives of large, complex river basins. WRIMS integrates a simulation language for flexible operational criteria specification, a linear programming solver for efficient water allocation decisions, and graphics capabilities for ease of use. These combined capabilities provide a comprehensive and powerful modeling tool for water resource systems simulation. The latest available version is 1.2.4b. 
CalSim is the model used to simulate California State Water Project (SWP)/Central Valley Project (CVP) operations. CalSim 2 is the latest version of CalSim available for use. 

The California Department of Water Resources (DWR) and the U.S. Bureau of Reclamation Mid-Pacific Region (USBR) have developed CalLite as an interactive screening model for evaluating various Central Valley water management alternatives.  CalLite simulates the hydrology of the Central Valley, reservoir operations, delivery allocation decisions, delta salinity, and habitat-ecosystem flow indices over an 82 year planning period. CalLite maintains the hydrologic, operational and institutional integrity of  CalSim; the results obtained from a typical CalLite run (<10 minute run time) are within 1% of a corresponding CalSim run (30 minute run time).

C2VSim is computer program that simulates water movement through the linked land surface, groundwater and surface water flow systems in California’s Central Valley. The C2VSim model contains monthly historical stream inflows, surface water diversions, precipitation, land use and crop acreages from October 1921 through September 2009. C2VSim dynamically calculates crop water demands, allocates contributions from precipitation, soil moisture and surface water diversions, and calculates the groundwater pumpage required to meet the remaining demand. It simulates the historical response of the Central Valley’s groundwater and surface water flow system to historical stresses, and can also be used to simulate the response to projected future stresses. DWR is providing C2VSim to Groundwater Sustainable Agencies (GSAs) as a tool that can be used in the SGMA program to develop their Groundwater Sustainability Plans (GSPs).
The Department of Water Resources (DWR) is developing a new model, the Sacramento Valley Groundwater-Surface Water Simulation Model (SVSim), scheduled for completion by December 31, 2017. This new model will support two important DWR programs and has two main goals: 1) Water Transfer Program - develop a tool that meets essential modeling requirements for evaluating project-specific impacts of groundwater substitution transfers on stream depletion in the Sacramento Valley and 2): Sustainable Groundwater Management Program - develop a tool for evaluating water budgets, SW‐GW interactions, land subsidence, and sustainable groundwater management scenarios in the Sacramento Valley.  The intended users of SVSim are DWR, transfer projects, Groundwater Sustainability Agencies, local agencies, and interested stakeholders. SVSim is an application of the Integrated Water Flow Model (IWFM) numerical code and is based on DWR’s C2VSim model. SVSim provides an updated analysis of geologic and hydrogeologic data for the Sacramento Valley. The model domain includes all of the Sacramento Valley Basin, the Redding Area Groundwater Basin, and the Delta. The southern boundary of the model lies between the Mokelumne and Calaveras Rivers. SVSim includes nine layers of variable thickness that span the entire groundwater system. The base period of the model simulates conditions from 1973 to 2015.