The Northeastern San Joaquin County Groundwater Banking Authority (GBA) isdeveloping an integrated regional water management plan (IRWMP) to implement waterresource alternatives with the goal of sustaining groundwater use in the area. In thesystems model, the groundwater basin underneath the GBA region was modeled as fivesubbasins based on water districts, cities, and natural boundaries. The GBA modeldevelopment focused on constructing a simplified relationship for the interaction betweengroundwater and surface water using the detailed groundwater model previouslydeveloped for the study area.To analyze the preliminary IRWMP alternatives, each subbasin was modeled with itsown inflows and outflows, such as demands, water deliveries, river seepage, deeppercolation, lateral flow from surrounding subbasins, groundwater pumping, andinflow/outflow from the water supply projects. The projects included new conveyancestructures, new surface water storage reservoirs and diversions, treatment plantexpansion, water transfers, a regional banking program, reclamation, and demandmanagement measures. Water developed through these projects was used in the model asnew municipal and industrial supplies, agricultural in-lieu deliveries, and direct rechargeto the groundwater subbasins through ponds and field flooding.The systems model evaluated the preliminary alternatives' overall performance forsubsequent screening and definition of alternatives that allow the sustainablemanagement of the groundwater basin. The objective of this paper was to discuss thedevelopment of the systems model used to screen the initial IRWMP alternatives basedon increase in groundwater levels, capital, and operations and maintenance costs. Includes 7 references, table, figures.
