The South Platte Decision Support System Alluvial Groundwater Model, Denver, Colorado

The South Platte Basin is the most developed river basin in Colorado. The basin is a key economic center for the state. Water in the basin is used to supply many of the municipalities in the northern portion of the Colorado Front Range as well as extensive agricultural operations.  The South Platte Basin is over-appropriated, which means that the demand from water rights exceeds the physical supply.  

The Colorado Water Conservation Board (CWCB) and Colorado Division of Water Resources (DWR) have jointly developed the South Platte Decision Support System (SPDSS) to help manage water resources in the basin. One goal of the SPDSS was to develop an alluvial groundwater model to simulate the groundwater and surface water interactions in the basin.  The SPDSS alluvial groundwater model was developed using a data-centered approach in order to build upon existing data and tools developed by Colorado’s Decision Support Systems (CDSS). The state has developed a comprehensive water resources database called HydroBase. Data collected under the SPDSS was incorporated into HydroBase, and then data-centered processing tools were used to prepare model inputs.

A MODFLOW groundwater model was developed for the South Platte alluvial aquifer system using the data-centered process to facilitate the integration of new data as it becomes available. The SPDSS alluvial groundwater model will be used to make regional water resource planning decisions. The model will give planners and decision makers a tool with which they can evaluate the potential effects on water resources of the South Platte Basin due to changes in water resources operations and/or climate change.