Water Resources Research Act Program

Details for Project ID 2020AR003S

Analysis of groundwater contribution to the Black River near the Poplar Bluff, Missouri

Institute: Arkansas
USGS Grant Number: G20AP00033
Year Established: 2020 Start Date: 2019-12-15 End Date: 2022-02-28
Total Federal Funds: $243,688 Total Non-Federal Funds: Not available

Principal Investigators: Brian Haggard

Project Summary: Results of numerous studies show that a majority of water moving into a river during a flood event can be groundwater (including saturated-zone, unsaturated-zone, soil-zone, and bank-storage components). Groundwater contribution to a storm-event hydrograph peak often exceeds 60 percent to 90 percent. Relative groundwater levels near rivers can affect the rive hydrograph response during a rain event. Data on river-water sources and hydrograph response can provide information on the potential efficacy of engineered approaches to controlling local groundwater levels. The relative contributions of surface-runoff and groundwater components may be quantified by hydrograph separation techniques. Isotopic and chemical hydrograph separation, coupled with mixing models, can provide quantified estimates of relative surface-runoff and groundwater contributions that are much more accurate than physical hydrograph separations, and in some cases, can break out different groundwater components. The proposed study will develop and install a monitoring network that takes advantage of three existing stream-gaging locations and will include monitoring-well transect installation, collection of water isotopes data and select geochemical parameters and apply these data to 1) identify river-water contributing end members, 2) develop mixing models and 3) conduct isotopic and chemical hydrograph separations at three existing stream-gaging stations on the Black River in or near Poplar Bluff, Missouri. Hydrograph separation data will be analyzed to determine relative groundwater contributions to Black River flow, focusing on the late-spring to mid-summer season. Chemical and isotopic hydrograph separation data will be coupled with flow data from the existing stream gages, and with well-transect water-level data to quantify groundwater contribution to flow.