Trout Creek (aka Trout Run) IA 01-UIA-269
mouth (S23 T98N R8W Winneshiek Co.) to confluence with unnamed tributary (aka Trout Run) in S27 T98N R8W Winneshiek Co.
- Cycle
- 2020
- Release Status
- Final
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 8/24/2020 3:02:42 PM
- Updated
- 10/15/2020 10:58:15 AM
The Class A3 and the Class A2 uses both remain assessed as “not supported” due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BCW1 use remains assessed as “partially supported" based on biological sampling 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 BIO See Below 477 Trout Run Creek Decorah – REMAP #178 NEIARCD 19 WQ CY 2012-2014 191910009 Trout Run Creek Site 16 Class
A2 - 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 191910009 19 21 / 3 211 957 2034 Yes 6 29% Yes Evaluated Not Class
A3 - 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 191910009 19 21 / 3 211 957 2034 Yes 15 71% Yes Evaluated Not Class
A - pH: Site ID Data Source ID # Samples / # Years Maximum Value Mean Value Median Value # Violations % Violations Significantly >10% Violations Assessment Type Support Level 191910009 19 14 / 3 8.3 8.11 8.14 0 0% No Evaluated Full Class
BCW1 - 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 190050003 19 Ammonia 14 / 3 0.27 0.07 0.05 0 / 0 0% / 0% No Evaluated Full 190050003 19 pH 14 / 3 8.3 8.11 8.14 0 / 0 0% / 0% No Evaluated Full 190050003 19 Temperature 14 / 3 16.7 11.8 12.2 NA / 0 NA / 0% No Evaluated Full Class
BCW1 - Biological Sampling: Benthic
Macroinvertebrates: BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage/ Thermal BM Sample Gear CBI score CBI Class CBI BIT CBI Pass/ Fail 477 9/15/14 50 52b MS/CW Hess 61 NA 60 Pass 477 8/4/14 50 52b MS/CW Hess 38 NA 60 Fail 477 9/10/13 50 52b MS/CW Hess 44 NA 60 Fail 477 8/15/13 50 52b MS/CW Hess 53 NA 60 Fail Overall
Assessment: Community Assessment Type Assessment Result Support Level Earned IR Category Actual IR Category Reason Benthic Macroinvertebrates Evaluated Fail (1/4) Partial 3bc 5bv Assessment
is evaluated because samples used to complete assessment weren’t collected in
the last five years. Class
BCW1 – Trout Natural Reproduction: Based on the January 2020 trout reproduction in Iowa streams
summary prepared by the DNR Fisheries Bureau, the Class BCW1 coldwater aquatic
life use of Trout Creek (aka Trout Run) was assessed as "fully
supported". According to the updated summary, this stream was placed in
Category I: streams that exhibit consistent natural reproduction and maintain a
wild population of one or more trout species without any stocking. Class
BCW1 – Continuous Monitoring: Results
of continuous dissolved oxygen (DO) and temperature monitoring in 2013 and 2014
for the DNR/SHL coldwater stream sampling projects also suggested the Class
BCW1 aquatic life use was “fully supported”. The lowest DO concentration
recorded in 75 days of continuous monitoring was 8.3 mg/L. The daily DO minimum
concentration failed to meet the 24-hour DO criterion (5 mg/L) and the 16-hour
DO criterion (7 mg/L) in 0 of 75 days each. The percentages exceeding (0%) was
less than (passing) the 10% impairment threshold used to assess conventional
water quality parameters. The associated statistical analysis confidence level
was high (>90%). The maximum stream temperature recorded during the sensor
deployment period was 21.6 degrees (C). The BCW1 temperature criterion of 20
(C) was exceeded in 1 of 75 days. The percentage exceeding (1.3%) was less than
(passing) the 10% impairment threshold with high statistical confidence
(>90%). Based on these data, the BCW1 aquatic life use was assessed as not
impaired by DO and temperature. Class HH – No Data