THE UPPER LITTLE MIAMI RIVER BASIN BURIED VALLEY AQUIFER – A SUSTAINABLE GROUNDWATER RESOURCE?

Approximately 161,000 people located throughout Greene County, Ohio depend upon groundwater for their potable water. Most of the municipal/industrial water supplies in the county tap into an extensive network of buried valley aquifer(s) (BVA) beneath the Upper Little Miami River basin. This aquifer network is primarily recharged through surface water infiltration into outwash deposits underlying local rivers, streams and tributaries with additional recharge occurring from the bedrock walls of the BVA from Silurian-aged carbonates, where present. As demand for potable water in the area increases, a better understanding of the groundwater resources and their limitations is needed.

To estimate the sustainable production potential of this aquifer network, existing hydrologic and geologic information for the northern half of the county was compiled, evaluated and used to create a conceptual hydrogeologic model. To estimate water flux, the conceptual model was used as a basis for an annual water budget of the study area. Concurrently, specific information from the conceptual model was used to develop a numerical computer model using the MODFLOW code. After calibration, various simulations and resulting volumetric budgets were completed to assess the long-term water resource potential of the aquifer network. Model results suggest current production from existing pumping centers is sustainable and could be doubled, depending upon location. These projections assume no significant change in existing climatic conditions for the region.