Impaired Water - Castle Rock Creek (Fennimore Fork (Castle Rock))
Grant County, Wisconsin
21.39 - 26.25
Water is impaired due to one or more pollutants and associated quality impacts.
Sediment and phosphorus TMDLs approved 2004.
See also segment 3.
Listing Details
Sediment/Total Suspended Solids
Listed For
Fish and Aquatic Life
Degraded Habitat
Current Use
WWFF - Warmwater Forage Fishery
Listing Status
TMDL Approved
Attainable Use
Coldwater - stocked, reproduction
Not Applicable
Designated Use
Coldwater - stocked, reproduction
303(d) ID
Listing Date
Impaired Water Notes
Castle Rock Creek (also known as Fennimore Creek) (WBIC 1211300) from mile 15.5 to mile 26 and the entire 4 mile length of Gunderson Valley Creek (WBIC 1212600), a tributary to Castle Rock Creek are included on Wisconsin’s 2002 section 303(d) list of impaired waters.1 The streams are located in northeastern Grant County, Wisconsin and are part of the Blue River Watershed. The Blue River flows to the Lower Wisconsin River. Castle Rock Creek downstream from the impaired segment is designated as a state Outstanding Resource Water. Both streams were listed as a high priority for TMDL development on the October 2002 303(d) list.

Castle Rock Creek was listed as impaired due to degraded habitat due to sedimentation that limited the stream’s coldwater fishery to the extent that the stream’s designated use was not met. In addition, Castle Rock Creek has a substantial amount of filamentous algae that is not found in nearby trout streams.

Impaired Water Notes
The Castle Rock Creek sediment and phosphorus TMDL was approved by the USEPA August 20, 2004.