Groundwater Information

What is groundwater?

When rain falls, and hits the Earth, some flows downhill as runoff into a stream, lake or ocean. Some of that rain evaporates; some is taken up by plants. The rest trickles down through surface soil and rock. This water is groundwater, and it flows within the small spaces between soil particles and fractured rock.  The area where water fills these spaces is called the saturated zone- the top of which is commonly referred to as the water table.

Groundwater is found at varying depths everywhere. In some places, this water is nearly 1,000 feet below the surface. In Wisconsin, groundwater is much closer to the surface- typically within 100 feet. The water table may be shallow or deep; and may rise or fall depending on many factors including human usage, precipitation levels, and climate. Well drilling records for Dunn County indicate that the average depth to the water table is a little over 50 feet, but this ranges from just under the ground surface to nearly 400 feet below ground.