Dam information
The rivers, ponds and some wetlands in the Sheboygan River Basin contain about 48 dams of varying size and function. Some of these dams are small, privately owned structures. Others are old milldams that no longer operate water-powered machinery as the once did in our past history.
The Department of Natural Resources has a safety program established to inspect large dams. Over the next 5-6 years, they anticipate that approximately 10-12 of these large dams in the basin will be inspected to insure they are safe and can reasonable withstand the impacts of flooding.
Regardless of size, dams can have profound effect on stream ecosystems:
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Dams can change free-flowing streams into bodies of water more resembling ponds or lakes (called impoundments).
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Streams rely on periodic high flows to move sediment. Dams can dampen that effect. Because streams and rivers carry sediment and nutrients from runoff and natural processes, these impoundments tend to act as sinks that slowly fill with sediment and become shallow. Instead of being suspended in the water column and being deposited at river bends, sediment gets backed up behind dams and covers gravel areas that many species rely on for habitat and nesting sites.
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The water in these shallow ponds exhibit increased water temperature, which results in limiting the availability of dissolved oxygen for fish and other aquatic life. A dam on a cold water stream can allow for the water upstream on the dam to warm, which can have a negative effect on species sensitive to temperature fluctuations.
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Dams and their impoundments displace many of the native species that thrive in a flowing environment.
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Dam structuresh a prevent or slow migration of fisnd other aquatic life within the stream environment thereby having effects throughout the food chains of streams and rivers.
The WDNR does not normally pursue removal of dams if they are maintained in good condition. However, it is their experience that the removal of dams can often have beneficial impacts on rivers and streams. It is recognized that many dams continue to provide cultural, economic, historical and recreational values to landowners and some members of the public. The DNR will continue to address abandoned or unsafe dams in order to ensure preservation of life, health and property. Where possible, the DNR and various partners will continue to look for opportunities to remove dams that no longer serve a purpose or are unsafe or abandoned.