Winnebago River IA 02-WIN-827
from confluence with Calmus Cr. (S34 T97N R20W Cerro Gordo Co.) to mill dam at Fertile in S34 T98N R22W Worth Co.
- Cycle
- 2020
- Release Status
- Final
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 9/9/2020 7:09:43 AM
- Updated
- 10/16/2020 10:09:51 AM
The presumptive Class A1 use remains assessed as "partially supported" due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BWW1 use was assessed as "fully supported" based on biological sampling data and on ambient water quality monitoring data. All other designated uses were "not assessed".
Sources of Data: Data
Source Data
Source ID Data Type Data Age Site ID Site Name Site
Description Iowa DNR 6 WQ CY 2012-2014 10170002 Winnebago
River Upstream of Mason City (US1) Iowa DNR 6 BIO See Below 953 Winnebago
River Mason City
– US1
Presumptive Class A1 - Indicator Bacteria: 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 10170002 6 21 / 3 279 87 170 Yes 7 33% Yes Evaluated Partial
Presumptive Class A1 - pH: Site ID Data
Source ID # Samples
/ # Years Maximum
Value Mean Value Median
Value #
Violations %
Violations Significantly
>10% Violations Assessment
Type Support
Level 10170002 6 33 / 3 8.5 8.1 8.1 0 0% No Evaluated Full
Class BWW1 - Conventional Parameters: Site ID Data
Source ID Parameter
Name # Samples
/ # Years Maximum
Value Mean Value Median
Value # Acute /
Chronic Violations % Acute/
Chronic Violations Significantly
>10% Violations Assessment
Type Support
Level 10170002 6 Ammonia 33 / 3 0.72 0.11 0.05 0 / 0 0% / 0% No Evaluated Full 10170002 6 Chloride 33 / 3 120 27 24 0 / 0 0% / 0% No Evaluated Full 10170002 6 Dissolved
oxygen 33 / 3 15.7 10.2 9.9 NA / 0 NA / 0% No Evaluated Full 10170002 6 pH 33 / 3 8.5 8.1 8.1 0 / NA 0% / NA No Evaluated Full 10170002 6 Sulfate 33 / 3 130 68 70 0 / NA 0% / NA No Evaluated Full 10170002 6 Temperature 33 / 3 28.3 11.7 14.5 0 / 0 0% / 0% No Evaluated Full
Class BWW1 - Biological
Sampling: Benthic
Macroinvertebrates: BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage/Thermal BM Sample Gear BMIBI score BMIBI Class 47c BMIBI BIT BMIBI Pass/ Fail 953 9/8/14 463 47c MS/WW Hess 80 Excellent 70 Pass 953 9/8/14 463 47c MS/WW Float ArtSub 80 Excellent 52 Pass 953 9/4/13 463 47c MS/WW Hess 73 Good 70 Pass 953 9/4/13 463 47c MS/WW ArtSub 77 Excellent 52 Pass
Overall: Community Assessment Type Assessment Result Support Level Earned IR Category Actual IR Category Reason Benthic Macroinvertebrates Evaluated Pass (4/4) Full 1 1 Assessment is evaluated because it included samples collected not in the last five years. Class HH - No Data