Fish diversity:
- The Mukwonago River is home to over 50 different species of fish. For a stream of this size, over 20 species would be considered quite diverse. Only much larger systems like the Wisconsin and the Mississippi have comparable levels of fish diversity.
- 10 of the state’s 11 species of Sunfish (including the threatened Longear Sunfish) live in the Mukwonago River. It is the only stream in Wisconsin where this occurs.
- All three species of Killifish (or Topminnows) found in Wisconsin, including the federally endangered Starhead Topminnow, live in the Mukwonago River. This is the only stream in the state where this occurs.
- The Mukwonago supports numerous species of Shiners and Darters, fish species that are not necessarily unique, but are indicators of good water quality and habitat.
Freshwater mussel diversity:
- The Mukwonago River contains 15 different species of freshwater mussels, including the endangered Rainbow Shell and the threatened Slippershell and Ellipse mussels. Mussels are the most threatened family of animals in North America, due principally to water quality deterioration in most of the nation’s freshwater bodies.
High quality, diverse wetlands:
- The Mukwonago River watershed features a diverse and extensive system of intact wetlands that help support its high water quality and species diversity. These wetlands are one of the important reasons explaining why the Mukwonago River is known as one of the most biologically diverse and highest quality rivers in the state.
Excellent overall ecosystem condition:
- Due to its excellent water quality, minimal level of disturbance, and diverse habitat types (particularly the abundant spring-fed wetlands), the river also supports a high diversity of waterfowl, reptiles, amphibians, insects, aquatic plants, and wetland types. The Mukwonago, for example, supports one of the last and largest stands of wild rice in Southeastern Wisconsin.
High rates of groundwater recharge:
- Due in large part to the glacial soils found throughout most of the watershed, and combined with the fact that the watershed is relatively undeveloped, groundwater recharge rates in the watershed are significant. Much of the life described above relies heavily on the consistent inflow of groundwater for its survival. The human communities in the watershed also rely on the groundwater aquifers supplied by this recharge. Today, those aquifers are being pumped excessively potentially threatening the future economic viability of the region – maintaining groundwater recharge wherever possible is more important than ever.
Other good things to know about the Mukwonago River:
Due to the factors listed above, the Wisconsin Chapter of The Nature Conservancy has designated the Mukwonago River watershed one of its four “Last Great Places” in Wisconsin.
Because of its high quality waters and wetlands, the Mukwonago River watershed was selected in the early 2000’s as one of three focal sites globally to be reviewed by the international Nature Conservancy Wetlands Network. The other two sites are the Amazon River and the Great Salt Lake Marsh. The network was comprised of some of the most knowledgeable wetlands academics, scientists, and managers in the world.
The challenge of protecting the outstanding resources of the Mukwonago River in the face of development pressure and other potential threats is one that the watershed community is capable of meeting, provided that we put our minds to it and work collaboratively. Where development is to occur, practices exist for development design, stormwater management, and land and water conservation that will serve to help us meet these objectives. Where appropriate, public and private land preservation can play a key role in protecting the natural heritage of the Mukwonago River watershed for the enjoyment of current and future generations.
We formed Friends of the Mukwonago River in 1999 to provide a voice for this incredible river and its watershed in local decision making. We want to ensure that the wonderful qualities that make the Mukwonago River so special are maintained for future generations. In order to do that, we will need help. If you would like to help us, click here.