Lower Rock River groundwater
Groundwater is an important resource of the Lower Rock River basin. It is the source of almost all water used for domestic, agricultural, commercial and industrial purposes in the basin. All of the basin's residents rely on groundwater for potable water supply.
The rural population typically uses shallower, less protected aquifers than the urban population, which is served by public water supplies and typically deeper wells. The reliance on groundwater in this basin is similar to use patterns throughout the state. The primary use of groundwater is for residential purposes such as drinking water, cleaning and sanitation, followed by industry and irrigation.
Groundwater is stored in aquifers and is also discharged to streams, lakes and wetlands as base flow. Groundwater discharges an estimated 16 billion gallons of water per day to lakes and streams in Wisconsin (Holt). Baseflow can be a major source of streamflow and its contributions are vital to stream ecology. Because of its importance, we need a greater understanding of groundwater and of existing and potential threats to its quality and quantity.
The Lower Rock River basin includes 15 watersheds encompassing parts of Columbia, Dane, Rock, Jefferson, Washington, Waukesha and Walworth counties. The overall drainage basin encompasses 1,857 square miles (4,809 square kilometers). Maintaining the basin's groundwater quality is essential to make the Lower Rock River basin an attractive place to work and live.
The key to groundwater protection is the prevention of groundwater contamination. Contamination prevention is the best public policy and is more cost-effective than remediation of contaminated groundwater.