In response to the December 2003 recommendations made by the CALFED Science Program review panel on improvements to the existing CalSim-II Water Resources Planning Model, DWR and Reclamation jointly developed a program to enhance the capabilities of the model and improve on the applicability of the model in use for water resources planning in California. The highest priority in this phase of model development is given to overhauling the representation of the Sacramento Valley hydrology. Among the features of this development project are 1) defining new water budget area boundaries (WBAs) for a higher resolution representation of the physical system, 2) enhancement of methodologies for estimating local water supplies, 3) developing a more accurate representation of the SWP/CVP and non-project demands in the Sacramento Valley, 4) enhancement of procedures for allocating priorities to meet demands from multiple sources of surface water and ground water, and 5) enhancement of current and/or development of new methodologies for simulating ground water flow and the surface water-ground water interaction. This effort will result in a new schematic representation of the water resources system.

Services of the MWH of Americas, Inc. have been retained through a one-year contract to assist the agencies modeling staff in completing the required tasks of this phase of model development.

This web site has been designed for public access to the CalSim-III Hydrology Development Project. It includes project work plan and timeline, technical memoranda on completed project tasks, documentation of the history of this phase of model development, all public documents regarding the awarded contract, as well as links to all relevant DWR sites.