Systems Modeling for Development and Analysis of Alternatives for Sustainable Groundwater Management

摘要

Systems models play an important role in regional water resources planning efforts. Detailed surface water and groundwater models can investigate minute changes to their systems, but dynamic systems models integrate the complex variables of water supplies, water uses, economic considerations, and qualitative measures. These models are valuable decision-making tools for water agencies faced with defining alternatives to meet multiple objectives. The Northeastern San Joaquin County Groundwater Banking Authority (GBA) is developing an integrated regional water management plan (IRWMP) to implement water resource alternatives with the goal of sustaining groundwater use in the area. In the systems model, the groundwater basin underneath the GBA region was modeled as five subbasins based on water districts, cities, and natural boundaries. The GBA model development focused on constructing a simplified relationship for the interaction between groundwater and surface water using the detailed groundwater model previously developed for the study area. To analyze the preliminary IRWMP alternatives, each subbasin was modeled with its own inflows and outflows, such as demands, water deliveries, river seepage, deep percolation, lateral flow from surrounding subbasins, groundwater pumping, and inflow/outflow from the water supply projects. The projects included new conveyance structures, new surface water storage reservoirs and diversions, treatment plant expansion, water transfers, a regional banking program, reclamation, and demand management measures. Water developed through these projects was used in the model as new municipal and industrial supplies, agricultural in-lieu deliveries, and direct recharge to the groundwater subbasins through ponds and field flooding. The systems model evaluated the preliminary alternatives’ overall performance for subsequent screening and definition of alternatives that allow the sustainable