Observing, Documenting, And Quantifying Flow From A Reservoir To A Karst Aquifer

Surface-water/groundwater interactions from constructed reservoirs are less studied than the interconnections from natural lakes. Reservoirs have been constructed to manage water supply for a thirsty populace and provide flood protection for development. Stillhouse Hollow Reservoir was impounded in 1968 and anecdotal evidence of increased spring flow below the dam has been a topic of conversations ever since. A recent study combining flow, ionic chemistry, stable isotopes, and environmental DNA confirm surface-water connections from the reservoir to the local groundwater flow system. The surface-water/groundwater interaction between the reservoir and the aquifer exhibited heterogeneity characteristic of the karst aquifer but followed a general flow path. Results may have important implications regarding groundwater quality and use below the reservoir while quantity estimates may encourage management for enhanced aquifer recharge.