Year Established: 2018 Start Date: 2018-03-01 End Date: 2019-02-28
Total Federal Funds: $4,996 Total Non-Federal Funds: $2,598
Principal Investigators: Ryan Bailey
Abstract: When a pumping well lowers water table elevations adjacent to a nearby stream a strong hydraulic gradient develops which results in a process referred to as streamflow depletion. Being able to accurately model the severity of this process is of critical importance in semi-arid regions where understanding groundwater-surface water interactions is crucial for sustainable water resource practices. The aim of the study is to complete an ongoing project that uses a combination of field data and groundwater modeling to determine the nature of pumping-induced streamflow depletion at a site along the South Platte River in south Denver. Data collection and modeling have been performed during the past 12 months, but should be continued through 2018 to provide complete results. Results from the field data will be compared with the Glover solution for estimating streamflow depletion (SFD), which is currently the most accepted method for calculating SFD in many water rights decisions across the state. These data will then serve as a means of calibration for a MODFLOW model that employs a new module developed by PI Flores to better model stream-aquifer interactions. The new module uses the one-dimensional shallow water equations to compute stream stage along the length of the river reach, which allows for more detailed and accurate interactions with the underlying aquifer. Near the end of this study, this new module and its application to the South Platte River study site will be published in a high-impact water resources journal. Overall, this study will enhance understanding of surface water/alluvial aquifer interactions when high-capacity pumping occurs near a stream. Methods and results can be used as guidelines for other field studies and also assist in determining impact of pumping on surface water in water rights cases.