Cedar River IA 02-CED-468
from dam of Cedar Falls Impoundment (NW 1/4 S12 T89N R14W Black Hawk Co.) to upper end of impoundment (W line S2 T89N R14W Black Hawk Co.)
- Cycle
- 2026
- Current Phase
- Public Comment
- Overall IR
- 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
- Trend
- Stable
- Created
- 10/27/2025 3:09:26 PM
- Updated
- 12/3/2025 12:44:09 PM
The Class A1 use was assessed as "not supported" based on levels of indicator bacteria that violated state water quality criteria. The Class BWW1 use was assessed as "fully supported" based on biological sampling data. All other designated uses were "not assessed." Note: A TMDL for the bacteria impairment in this segment of Cedar River was prepared and was approved by EPA in February 2010. The bacteria impairment of the Class A1 primary contact recreation use for this segment was moved to IR Category 4a (TMDL prepared and approved).
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2012-2014 10070005 Cedar River upstream of Waterloo/Cedar Falls Iowa DNR 6 BIO See Below 1197 Cedar River Cedar Falls – REMAP
#432 Site ID Data Source ID # Samples / # Years 2012 Geometric Mean 2013 Geometric Mean 2014 Geometric Mean Annual Geometric Mean Violation # Violations % Violations Significantly >10% Violations Assessment Type Support Level 10070005 6 22 / 3 26 99 58 No 5 21% Yes Evaluated Not Site ID Date Drainage Area (mi2) Ecoregion Major Drainage BM Sample Gear BMIBI score BMIBI Class 47c BMIBI BIT BMIBI Pass/Fail 1197 8/21/19 4720 47c MS Floating Art Sub 66 Good 52 Pass Site ID Date Drainage Area (mi2) Ecoregion Major Drainage Riffle Stream? FIBI score FIBI Class 47c FIBI BIT FIBI Pass/Fail 1197 8/21/19 4720 47c MS Undetermined 50 Fair 44 Pass Community Assessment Type Assessment Result Support Level IR Category Reason Benthic
Macroinvertebrates Evaluated Pass (1/1) Full Fish Evaluated Pass (1/1) Full Assessment was
evaluated because the drainage areas of the sample site Overall Evaluated Pass Full 1 was greater than the
calibrated range.
Class A1 – Indicator Bacteria: 2012-2014
Class BWW1 - Biological Sampling:
Benthic Macroinvertebrates:
Fish:
Overall:
Class HH – No Data