Baseflow Indicators for Groundwater Protection Regions

With shifting climatic patterns that affect precipitation volume and frequency, compounded with increasing demands for water, better understanding of the groundwater links to surface water recharge are increasingly in demand. The objective of our research is to provide metrics to determine regions requiring groundwater protection measures based on baseflow predictions. In 2005, a moderate drought occurred within the Fox-Wolf Basin in Northeast Wisconsin. We took 176 discharge spot measurements in the headwater regions of the basin during the summer of 2005 and performed 10-12 repeat measurements at 46 sites during the summer of 2005 and 2006, for a total of 306, measurements. Our confirmed hypothesis is that stream length (distance from headwater to spot measurement) correlates better with baseflow discharge than watershed area. Additionally, we found that landuse had a subtle effect on metrics. Finally, our measurements were compared with USGS spot discharge measurements taken during a severe drought in 1970s. The two data sets show a high degree of correlation but indicate that baseflow water levels are significantly and systematically lower.