A watershed is an area of land that drains to a common body of water. A watershed is defined not by political boundaries, but by geographical barriers such as a ridge, hill, or mountain that determine how the water flows over the landscape. As a drop of rain falls on the land, it flows downhill into small creeks and streams, then into larger rivers, and eventually into lakes, wetlands, or the ocean. Some rain also evaporates back into the air, or filters into the soil where it is either taken up by plants or drains into the subsurface and becomes groundwater. (Diagram - MPCA)
The Zumbro Watershed encompasses more than 900,000 acres (or ~1,422 square miles) of agricultural and urban lands that drain into the three forks of the Zumbro River before joining the Mississippi River at Kellogg, MN.
The watershed contains more than 288 miles of rivers and streams, including 57 miles of high-quality trout streams, a smallmouth bass fishery, and a designated canoe trail. The watershed covers parts of six counties - Dodge, Goodhue, Rice, Olmsted, Steele, and Wabasha - and 22 municipalities, including the growing City of Rochester.
The Zumbro Watershed is home to bald eagles, great blue herons, beavers, river otters, coyotes, smallmouth bass, brook trout and more than 150,000 people who live, work, and play within its boundary.
The Zumbro Watershed is known for its diversity of landscape, ranging from deep fertile glacial-tills, to steep sandy soils of the bluffs. Portions of the Zumbro Watershed are included in what is called the "driftless area," the area was by- passed by the last continental glacier that has differential weathering and erosion that results in a steep, rugged landscape referred to as karst topography.