The importance of the ground-water

Ground water is a major natural resource in the Great Lakes Region that helps link the Great Lakes and their watershed.

The Great Lakes constitute the largest concentration of unfrozen fresh surface water in the western hemisphere. Ground water, however, is more important to the hydrology of the Great Lakes and to the health of ecosystems in the
watershed than is generally recognized.

Ground water that normally discharges to streams, lakes, and wetlands can be captured by pumping (the most common form of development), which may deplete or reduce inflows to the Great Lakes.

Ground water is important to ecosystems in the Great Lakes Region because it is, in effect, a large, subsurface reservoir from which water is released slowly to provide a reliable minimum level of water flow to streams, lakes, and
wetlands. It's discharge too to streams generally provides good quality water that, in turn, promotes habitat for aquatic animals and aquatic plants during periods of low precipitation. Because of the slow movement of ground water, the effects of surface activities on ground-water's flow and quality can take years to manifest themselves. As a result, issues relative to ground water are
often seemingly less dire than issues related to surface water alone.

“Water quantity and water quality are inextricably linked.
For most uses, quantity alone does not satisfy the
demand.”

—Interim IJC Report.

In addition to water quality also can be of concern. As development increases, activities that could threaten the quality of ground water also increase. Human health needs to be safeguarded, does the health of many other organisms
that clean water.

-Ainoa Quiñones García
mi.water.usgs.gov/pdf/wrir_00-4008.pdf