Portage County has abundant water resources that include surface water features (numerous lakes, miles of streams and rivers, and wetlands) and groundwater. Groundwater is the water that fills the spaces and pores of unconsolidated materials such as sand, silt, and clay, and fractures in the bedrock.
Groundwater does not remain stagnant but rather moves downward through the spaces, pores, and fractures under the influence of gravity; that is, it moves from higher to lower elevations. Groundwater movement can be determined by measuring the difference in elevation between two areas. Groundwater moves from high elevations to low elevations, where it discharges to streams, lakes, and wetlands. Once groundwater is discharged into these areas, it is referred to as surface water. Surface water in Portage County is where the water table intersects the land's surface, thus making groundwater and surface water directly connected to one another. The cycle of precipitation, groundwater recharge, and discharge to surface waters is a balanced natural system. During drier years, less recharge occurs and water levels and stream levels decline. During wet years, recharge is greater and levels and stream flows can increase. Water usage and pumping can also influence this system.
Picture courtesy of the Groundwater Foundation.
These water resources are essential to support the daily living needs of all Portage County residents, a thriving commercial, agricultural, and industrial economy, the quality of life in rural communities, and recreational opportunities. The groundwater resource supports 100% of domestic water use, 87% of irrigation water, and 68% of industrial water use in Portage County (Data from Wisconsin Department of Natural Resources).