The Sugar River Watershed

The Sugar River Watershed covers nearly a half million acres (760 square miles) in south-central Wisconsin and northern Illinois. The watershed begins in the outskirts of Madison, Wisconsin and ends near Shirland, Illinois where the Sugar River flows into the Pecatonica River. Although the watershed is largely rural, with over 80% of the land used for agriculture, it also includes the population centers of Verona, New Glarus, Belleville, Evansville, Monticello, Albany, Brodhead, Lake Summerset, Durand, and portions of Madison, Fitchburg, and Mt. Horeb among others. 

Millennia of human occupation and land management using fire shaped this landscape before recent European settlement. Historically, the landscape was characterized by vast stretches of savanna, prairie, and barrens that occupied the broad sandy glacial outwash plain and surrounding hills. The Lower Sugar River watershed also includes the eastern edge of the Driftless Area of southwestern Wisconsin, characterized by dramatic limestone and older sandstone outcroppings, adding to the rich biological diversity of the basin. 

The Sugar River Watershed is divided into three parts:

The Upper Sugar River Watershed – This section encompasses the Sugar River and the land from Madison to Belleville, and is under the stewardship of our sister organization, The Upper Sugar River Watershed Association (USRWA).

The Middle Sugar River Watershed – This covers the stretch of the Sugar River as it flows between Belleville and Albany, Wisconsin.

The Lower Sugar River Watershed – The Lower Sugar River Watershed is composed of the Sugar River and 13 subwatersheds. This unique watershed covers 192,617 acres (301 square miles). It begins near Albany, WI in the north, extends west to the outskirts of Monroe, east to Orfordville, and south to Shirland, IL where it flows into the Pecatonica River, crossing the boundaries of four counties and two states. The watershed covers portions of Green and Rock Counties in Wisconsin and Stephenson and Winnebago Counties in Illinois. The Lower Sugar River, as with the majority of the Sugar River basin, is largely rural in nature with 79 percent of the land use within the watershed consisting of agricultural land. The remaining land use in the watershed is a matrix of forests (8%), developed lands (6%), wetlands (5%), shrublands (1%), grasslands (1%), barren lands (0.1%), and water (0.4%).  

In the Lower Sugar River Watershed alone, over 7,000 acres of restored and protected lands provide flood protection, wildlife habitat, and water quality benefits in and downstream of the watershed, as well as hunting, fishing, trapping and other outdoor recreation opportunities. Of the hundreds of miles of streams and rivers that drain the Sugar River basin, several are considered Outstanding or Exceptional Resource Waters, which are higher quality stream environments containing rare fishes and other aquatic life forms. Three streams in the LSRW are classified as Impaired Waters under the Clean Water Act Section 303(d), due to excessive sediment and nutrient loading. Impaired waters do not meet water quality standards and may not support fishing, swimming, recreating or public health and welfare. 

The Lower Sugar River Water Association is working with its partners to help restore some of these impaired streams to ensure that everyone in the watershed can enjoy clean water and all of the benefits of our beautiful watershed area.