Winnebago River IA 02-WIN-826
mouth (Floyd Co.) to confluence with Calmus Cr. at Mason City in S34 T97N R20W Cerro Gordo Co.
- Cycle
- 2020
- Release Status
- Final
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 9/8/2020 3:08:53 PM
- Updated
- 10/16/2020 10:07:14 AM
The Class A1 use remains assessed as "partially supported" due to levels of indicator bacteria (E. coli) that violated state water quality criteria. The Class BWW1 use was assessed as "partially supported” based on biological sampling data. The Class HH use remains assessed as "fully supported" based on fish tissue sampling data.
Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2012-2014 10170003 Winnebago River Downstream of
Mason City (DS1) Iowa DNR 6 BIO See Below 954 Winnebago River Mason City – DS1 Iowa DNR 6 BIO See Below 1035 Winnebago River near Fossil Rock
Park WN002 Iowa DNR 6 FT See Below 135 Winnebago River E of Mason City
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 10170003 6 22 / 3 387 222 371 Yes 13 59% 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 10170003 6 33 / 3 8.5 8.1 8.2 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 10170003 6 Ammonia 33 / 3 0.49 0.11 0.05 0 / 0 0% / 0% No Evaluated Full 10170003 6 Chloride 33 / 3 150 50 41 0 / 0 0% / 0% No Evaluated Full 10170003 6 Dissolved oxygen 33 / 3 15.4 10.8 11.1 NA / 0 NA / 0% No Evaluated Full 10170003 6 pH 33 / 3 8.5 8.1 8.2 0 / NA 0% / NA No Evaluated Full 10170003 6 Sulfate 33 / 3 110 70 74 0 / NA 0% / NA No Evaluated Full 10170003 6 Temperature 33 / 3 26.8 11.5 14.7 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 954 9/8/14 654 47c MS/WW Float
ArtSub 56 Good 52 Pass 954 9/8/14 654 47c MS/WW Hess 66 Good 70 Fail 954 9/4/13 654 47c MS/WW Hess 69 Good 70 Fail 954 9/4/13 654 47c MS/WW ArtSub 48 Fair 52 Fail 954 8/7/12 654 47c MS/WW Hess 70 Good 70 Pass 954 8/7/12 654 47c MS/WW ArtSub 72 Good 52 Pass Fish: BioNet
Site ID Date Drainage
Area (mi2) Ecoregion Major
Drainage/Thermal Riffle
Stream? FIBI
score FIBI
Class 47c
FIBI BIT FIBI
Pass/ Fail 1035 8/13/18 695 47c MS/WW Und 54 Good 44 Pass 1035 7/12/17 695 47c MS/WW Und 44 Fair 44 Pass 1035 7/20/15 695 47c MS/WW Und 44 Fair 44 Pass 1035 7/21/14 695 47c MS/WW Und 42 Fair 44 Fail
Overall: Community Assessment
Type Assessment
Result Support
Level Earned
IR Category Actual
IR Category Reason Benthic Macroinvertebrates Evaluated Fail
(3/6) Partial Fish Evaluated Pass
(3/4) Full Overall Evaluated Fail Partial 3bu 3bu Assessment is evaluated because the drainage
areas of the sample sites were larger than the calibrated range.
Class HH – Fish Tissue Sampling: Site ID Date Species Name Biopart # in sample chlordane result chlordane violation
(>0.6)? PCBs result PCBs violation
(>0.2)? Hg result Hg violation
(>0.3)? Assessment Type Support Level 135 8/21/2015 walleye plug 5
0.092 No Monitored Full 135 8/28/2012 walleye plug 5
0.218 No Evaluated Full 135 8/28/2012 common carp fillet 5 <0.03 No <0.09 No 0.122 No Evaluated Full