Impaired Water - Rock River (Rock River)
Rock County, Wisconsin
LR02, LR03, LR04, LR05
788800
183.45 - 193.11
9.66
Water is impaired due to one or more pollutants and associated quality impacts.
Notes
On 303d List since 1998 for Total Phosphorus and Total Suspended Solids. The TMDL for the Rock River basin was approved in September 2011. Specific Fish Consumption Advisory for PCBs was removed.

This water was assessed during the 2012 listing cycle, and total phosphorus sample data exceed 2012 WisCALM listing criteria for the fish and aquatic life use; however, available biological data do not indicate impairment (i.e. no macroinvertebrate or fish Index of Biotic Integrity (IBI) scored in the "poor" condition category).

This water was assessed during the 2014 listing cycle; total phosphorus sample data overwhelmingly exceed 2014 WisCALM listing thresholds for the Fish and Aquatic Life use, however, no biological data (i.e. no macroinvertebrate or fish Index of Biotic Integrity (IBI) scores) were available to assess biological impairment).

This water was assessed during the 2016 listing cycle; total phosphorus sample data overwhelmingly exceeded 2016 WisCALM listing criteria for the Fish and Aquatic Life use and biological impairment was observed (i.e. at least one macroinvertebrate or fish Index of Biotic Integrity (IBI) scored in the poor condition category).
Listing Details
Pollutant
Total Phosphorus
Listed For
Fish and Aquatic Life
Impairments
Low DO
Current Use
WWSF - Warmwater Sport Fishery
Listing Status
TMDL Approved
Attainable Use
WWSF - Warmwater Sport Fishery
Priority
Not Applicable
Designated Use
WWSF - Warmwater Sport Fishery
303(d) ID
400
Listing Date
4/1/1998
Impaired Water Notes
There are many lakes, rivers or streams in the Rock River Basin that are included on the
303(d) List. This effort is focused on those waters that are impaired by either excessive
sediment, high phosphorus concentrations, or both sediment and phosphorus (see Table 1).
These pollutants cause impacts to waterways which include low dissolved oxygen
concentrations, degraded habitat, and excessive turbidity. All of these problems result in
harm to fish and aquatic life, water quality, recreation and even navigation. Everyone who
lives or recreates in the Rock River basin will benefit from the improved water quality that will
result from reduced sediment and phosphorus
Date
12/1/2006

Impaired Water Notes
The Rock River (788800, miles 171.1-304.9) is a part of the Rock River Basin and is listed as impaired for sediment/total suspended solids and total phosphorus. The Rock River Basin TMDLs for phosphorus and sediment were approved by the USEPA September 28, 2011.
Date
5/8/2012

Impaired Water Notes
This water was assessed during the 2014 listing cycle; total phosphorus sample data overwhelmingly exceed 2014 WisCALM listing thresholds for the Fish and Aquatic Life use, however, no biological data (i.e. no macroinvertebrate or fish Index of Biotic Integrity (IBI) scores) were available to assess biological impairment).
Date
4/1/2014

Impaired Water Notes
This water was assessed during the 2016 listing cycle; total phosphorus sample data overwhelmingly exceeded 2016 WisCALM listing criteria for the Fish and Aquatic Life use and biological impairment was observed (i.e. at least one macroinvertebrate or fish Index of Biotic Integrity (IBI) scored in the poor condition category).
Date
9/24/2015

 
Pollutant
PCBs
Listed For
Fish and Aquatic Life
Impairments
PCBs Contaminated Fish Tissue
Current Use
WWSF - Warmwater Sport Fishery
Listing Status
Pollutant Removed
Attainable Use
WWSF - Warmwater Sport Fishery
Priority
Delisted 2006
Designated Use
WWSF - Warmwater Sport Fishery
303(d) ID
400
Listing Date
4/1/1998
Impaired Water Notes
New monitoring data for 399, 400, 401 Rock River Listings- FCA Impairment for PCBs pollutant should be removed. We have new data for Sites (2001/2002 Janesville to Afton, 2002 Indianford to Janesville, and 2003 Lake Koshkonong).
Date
4/1/2008

 
Pollutant
Sediment/Total Suspended Solids
Listed For
Fish and Aquatic Life
Impairments
Degraded Habitat
Current Use
WWSF - Warmwater Sport Fishery
Listing Status
TMDL Approved
Attainable Use
WWSF - Warmwater Sport Fishery
Priority
Not Applicable
Designated Use
WWSF - Warmwater Sport Fishery
303(d) ID
400
Listing Date
4/1/1998
Impaired Water Notes
There are many lakes, rivers or streams in the Rock River Basin that are included on the
303(d) List. This effort is focused on those waters that are impaired by either excessive
sediment, high phosphorus concentrations, or both sediment and phosphorus (see Table 1).
These pollutants cause impacts to waterways which include low dissolved oxygen
concentrations, degraded habitat, and excessive turbidity. All of these problems result in
harm to fish and aquatic life, water quality, recreation and even navigation. Everyone who
lives or recreates in the Rock River basin will benefit from the improved water quality that will
result from reduced sediment and phosphorus
Date
12/1/2006

Impaired Water Notes
The Rock River (788800, miles 171.1-304.9) is a part of the Rock River Basin and is listed as impaired for sediment/total suspended solids and total phosphorus. The Rock River Basin TMDLs for phosphorus and sediment were approved by the USEPA September 28, 2011.
Date
5/8/2012