Impaired Water - Prairie Brook (Prairie Brook)
Green County, Wisconsin
0.00 - 3.11
Water is impaired due to one or more pollutants and associated quality impacts.
On 2006 303d list, TMDL approved 2005; also on 1980 Trout Streams (class 3).
This two-mile long creek originates in western Green County and flows westward to Dougherty Creek. Prairie Brook Creek runs primarily through pasture and there is a considerable amount of bank erosion. However, the steep gradient of the stream maintains a sandy bottom with small amounts of gravel and cobble, as well as "good" width:depth ratio (8:1).

A macroinvertebrate assessment in 1990 described the water quality of this stream as "very good" with slight organic pollution (HBI = 3.636). Prairie Brook is currently classified as Class III trout stream (no evidence of natural reproduction) but is potentially a Class II. Fish monitoring conducted in 2002 recovered only two species (creek chub and brook stickleback) and a cold water index of biotic integrity was calculated as "poor". Habitat is very limited and fencing to prevent over pasturing would help improve the stream corridor.
Listing Details
Sediment/Total Suspended Solids
Listed For
Fish and Aquatic Life
Degraded Habitat
Current Use
Salmonid Populations Stocked
Listing Status
TMDL Approved
Attainable Use
FAL - Fish and Aquatic Life Community
Not Applicable
Designated Use
FAL - Fish and Aquatic Life Community
303(d) ID
Listing Date
Impaired Water Notes
This small steep stream drains an unglaciated valley and serves as a tributary to Dougherty Creek. The stream is valuable because it provides a source of cold water to Dougherty Creek (SurfaceWater Resources of Green Co, 1980). Heavily pastured, it suffers from streambank erosion; however the steep gradient maintains a sandy bottom with small amounts of gravel and cobble. Prairie Brook is a Class III trout stream whose potential is somewhat limited by flow. In (what year?) the Prairie Brook was added to the state’s list of impaired waters. The department and the Green County Land and Water Conservation Department should work with landowners to install best management practices and enforce NR151 to improve the riparian corridor of the stream. The stream was stocked with brook trout in 2005. It has not been monitored recently.

Impaired Water Notes
Prairie Brook (901500, miles 0-3.11) is part of the Sugar-Pecatonica River Basin and the sediment TMDLs were approved by the USEPA August 24, 2005.