Rock County, Wisconsin
LR02, LR03
788800
171.08 - 183.45
12.37
Water is impaired due to one or more pollutants and associated quality impacts.
Notes
This segment of the Rock River was put on the Impaired Waters List in the 1998 cycle for phosphorus, low dissolved oxygen, sediment, degraded habitat, and mercury and PCBs in fish tissue. The fish contaminants were removed from the list in the 2008 cycle. This segment of Rock River was evaluated every two-year cycle from 2012 to 2024; phosphorus data confirmed levels were too high. The TMDL plan for the Rock River Basin was approved in 2011. In the 2022 cycle bacteria data exceeded the new E. coli criteria. Pollutant
E. coli
Listed For
Recreation
Impairments
Recreational Restrictions - Pathogens
Current Use
Restricted Recreation
Listing Status
303d Listed
Attainable Use
Recreation
Priority
Low
Designated Use
Recreation
303(d) ID
2022-017
Listing Date
4/1/2022
Impaired Water Notes
This water was assessed during the 2022 listing cycle; new E. coli sample data exceeded 2022 WisCALM listing criteria for Recreation Use.
Date
6/12/2021
Pollutant
Sediment/Total Suspended Solids
Listed For
Fish and Aquatic Life
Impairments
Degraded Habitat
Current Use
Unsupported Aquatic Life
Listing Status
TMDL Approved
Attainable Use
WWSF - Warmwater Sport Fishery
Priority
Not Applicable
Designated Use
WWSF - Warmwater Sport Fishery
303(d) ID
401
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
Pollutant
PCBs
Listed For
Impairments
NA
Current Use
Listing Status
Pollutant Removed
Attainable Use
Priority
Delisted 2008
Designated Use
303(d) ID
401
Listing Date
4/1/1998
Pollutant
Mercury
Listed For
Impairments
NA
Current Use
Listing Status
Pollutant Removed
Attainable Use
Priority
Delisted 2008
Designated Use
303(d) ID
401
Listing Date
4/1/1998
Impaired Water Notes
Delisted in 2006 but not documented until 2008
Date
4/1/2008
Pollutant
Total Phosphorus
Listed For
Fish and Aquatic Life
Impairments
Low DO, Excess Algal Growth
Current Use
Unsupported Aquatic Life
Listing Status
TMDL Approved
Attainable Use
WWSF - Warmwater Sport Fishery
Priority
Not Applicable
Designated Use
WWSF - Warmwater Sport Fishery
303(d) ID
401
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 exceed 2014 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).
Date
4/1/2014
Impaired Water Notes
This water was assessed during the 2016 listing cycle; total phosphorus sample data exceed 2016 WisCALM listing criteria 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
10/7/2015
Impaired Water Notes
This water was assessed during the 2018 listing cycle; new total phosphorus sample data exceed 2018 WisCALM listing criteria 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
4/18/2017
Impaired Water Notes
This water was assessed during the 2020 listing cycle; new total phosphorus sample data exceed 2020 WisCALM listing criteria for the Fish and Aquatic Life use and biological impairment was observed (i.e. at least one macroinvertebrate Index of Biotic Integrity (IBI) scored in the poor condition category).New chloride sample data were clearly below 2020 WisCALM listing thresholds for the Fish and Aquatic Life use.
Date
6/17/2019