GROUNDWATER RESPONSE TO STREAM STAGE FLUCTUATIONS IN A REGULATED STREAM AT GLEN DALE, WEST VIRGINIA

Alluvial groundwater response to stream stage fluctuations was observed at the Glen Dale well field, examining a year-long time series of aquifer and stream stage. A convolution-integral method was used to simulate daily groundwater fluctuations at different distances from a stream induced by surface water transients. Additional hydraulic head above the calculated values are interpreted as recharge from precipitation. Results show that (i) stream stage fluctuations induced greater changes in groundwater levels than recharge especially during high flow periods and (ii) groundwater stage behavior was influenced by both pumping and seasonality. Aquifer diffusivities and lag time were estimated by peak matching of simulated to observed heads. Time varying unit-width bank storage and seepage rate were derived as a result of the model. This method could be a useful tool during incidents of surface water contamination for (i) a quick assessment of seepage rate and bank storage; (ii) identifying potential threats to water quality; and (iii) planning future well field expansion or management.