Impaired Water - Rock River (Rock River)
Dodge, Jefferson County, Wisconsin
LR11, LR13, UR01, UR08
788800
207.32 - 242.84
35.52
Water is impaired due to one or more pollutants and associated quality impacts.
Notes
This water was orginally listed as impaired in 2002 for Total Phosphorus. The TMDL was approved by the U.S. EPA in 2011. This segment of Rock River was evaluated every two-year cycle from 2012 to 2024; phosphorus levels were continuously elevated, reflected in poor biology (bugs and fish). Chloride levels were good.
Listing Details
Pollutant
Total Phosphorus
Listed For
Fish and Aquatic Life
Impairments
Degraded Biological Community, Low DO, Excess Algal Growth, Eutrophication
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
609
Listing Date
4/1/2002
Impaired Water Notes
This water was assessed during the 2018 listing cycle; new total phosphorus sample data overwhelmingly exceed 2018 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
7/19/2017

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.
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
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, and biological impairment was observed (i.e. at least one macroinvertebrate or fish Index of Biotic Integrity (IBI) scored in the “poor” condition category). A MIBI in 2009 scored in the poor condition category.
Date
6/17/2011

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 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
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
9/23/2015

Impaired Water Notes
This water was assessed during the 2020 listing cycle; new total phosphorus sample data overwhelmingly 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). Chloride was also assessed and did not exceed 2020 WisCALM listing criteria.
Date
6/14/2019

Impaired Water Notes
This water was assessed during the 2022 listing cycle; new total phosphorus sample data overwhelmingly exceed 2022 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).
Date
5/21/2021