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Lower Rock River Basin

The Rock River basin covers over 3,700 square miles and is located in the south-central part of Wisconsin. The basin's natural resources are the legacy of the last period of Wisconsin glaciation. Many Native American tribal peoples lived here because of the outstanding land, water and wildlife resources in the basin. European settlers described the basin as a paradise of fertile soils, large forests and many clear sparkling rivers and lakes. Much has changed over the last 150 years.

Today, most of the prairies and oak savannas are gone, the wetlands are diminished by 50% and most forests have been cut down to make way for agriculture. Currently, agriculture dominates the land use; however, urbanization in the basin is growing rapidly.

Overall, some of the Rock River basin's natural resources are slightly improved compared to 20 years ago. Land management and forestry law changes have supported a small increase in forests in the basin. Better treatment at wastewater treatment plants has improved water quality in some stretches of streams. Yet today, most water bodies in the basin remain significantly impacted by soil and nutrients washing into the streams and lakes from urban and rural stormwater runoff. Wildlife habitat continues to be lost and fragmentation of habitat accelerates.

Today, the most serious challenges facing the basin include:

  • Water quality impacts and increased runoff quantity from agriculture and urban land uses, such that many of the rivers and streams are not meeting water quality standards.
  • Loss of agricultural lands, with its effect on wildlife habitat, recreational usages, the rural landowners and economy.
  • Loss of critical sensitive habitat and connection between habitats.
  • Lower urban groundwater levels due to increased use and decreased groundwater infiltration due to more acres of impervious land.
  • Significant groundwater contamination in areas of the basin.

Water Resource Information For Specific Watersheds

Watershed Name/View Details Watershed size Lists (Streams, Lakes, Bays & Harbors) Counties Water Management Unit (WMU) Major Drainage System
Badfish Creek 84.21 mi 2 LR07 Water lists Dane, Green, Rock Lower Rock Mississippi River
Bark River 185.84 mi 2 LR13 Water lists Jefferson, Washington, Waukesha Lower Rock Mississippi River
Bass Creek 113.1 mi 2 LR03 Water lists Rock Lower Rock Mississippi River
Blackhawk Creek 108.11 mi 2 LR02 Water lists Rock, Walworth Lower Rock Mississippi River
Lower Koshkonong Creek 265.61 mi 2 LR11 Water lists Dane, Jefferson, Rock, Walworth Lower Rock Mississippi River
Marsh Creek 43.73 mi 2 LR05 Water lists Rock Lower Rock Mississippi River
Rock River - Milton 48.76 mi 2 LR04 Water lists Rock Lower Rock Mississippi River
Scuppernong River 87.43 mi 2 LR15 Water lists Jefferson, Walworth, Waukesha Lower Rock Mississippi River
Six Mile and Pheasant branch Creeks 119.45 mi 2 LR10 Water lists Dane Lower Rock Mississippi River
Turtle Creek 288.47 mi 2 LR01 Water lists Rock, Walworth Lower Rock Mississippi River
Upper Koshkonong Creek 104.25 mi 2 LR12 Water lists Dane, Jefferson Lower Rock Mississippi River
Whitewater Creek 75.3 mi 2 LR14 Water lists Jefferson, Rock, Walworth Lower Rock Mississippi River
Yahara River and Lake Kegonsa 126.33 mi 2 LR06 Water lists Dane, Rock Lower Rock Mississippi River
Yahara River and Lake Mendota 112.56 mi 2 LR09 Water lists Columbia, Dane Lower Rock Mississippi River
Yahara River and Lake Monona 93.73 mi 2 LR08 Water lists Dane Lower Rock Mississippi River