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.

Open Data Collection Period Modal

For purposes of developing stream/river water quality assessments for integrated reporting, three years of water quality data are typically used for both conventional pollutant parameters (e.g., indicator bacteria) and the less frequently monitored toxic parameters (e.g., toxic metals). Since the 2004 IR cycle, DNR has used a three-year data gathering period for streams, rivers, and beaches. For most assessments, the use of three years of data increases the number of samples upon which the decision on use support is based and helps address the problem of weather-related year-to-year fluctuations in water quality.

Due to the lower sampling frequency in Iowa’s ambient lake, biological, fish kill, and fish tissue monitoring programs, five years of data are used for developing IR assessments and for identifying Section 303(d) listings.

Data Type	Data Timeframe
Beach Sampling Data	CY 2020 - 2022
Stream/River Water Quality Data	CY 2020 - 2022
Lake Water Quality Data	CY 2018 - 2022
Biological Sampling Data	CY 2018 - 2022*
Fish Kill Data	CY 2018 - 2022
Fish Tissue Sampling Data	CY 2018 - 2022
Continuous Dissolved Oxygen Sampling Data	CY 2018 - 2022
*Biological sites sampled in both 2017 and 2021 were also assessed.

Open Segment Map
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Cycle: 2024
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Unknown
Created: 11/1/2023 8:12:37 AM
Updated: 1/9/2024 1:33:42 PM

Use Support

Class A2

Recreation - Secondary contact

Not Supported

Bacteria: Indicator Bacteria- E. coli

Support Level

Not Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

High

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2012

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Watershed project monitoring

TMDL Priority

Tier III

Class A3

Recreation - Children's contact

Not Supported

Bacteria: Indicator Bacteria- E. coli

Support Level

Not Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

High

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2008

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Watershed project monitoring

TMDL Priority

Tier III

Class BCW1

Aquatic Life - Cold Water Type 1

Not Supported

Biological: low aquatic macroinvertebrate IBI

Support Level

Not Supported

Impairment Code

5b-v - Biological - verified

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2016

Impairment Rationale

Low Biotic Index

Data Source

Biological monitoring: Iowa DNR WQMA

TMDL Priority

Tier IV

Class HH

Human Health -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class A3 and the Class A2 uses both were assessed as “not supported” due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BCW1 use was assessed as “not supported" based on biological sampling data. All other designated uses were "not assessed."

Assessment Explanation

Data Sources:

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 - Binomial 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	IR Category	Reason
Benthic Macroinvertebrates	Evaluated	Fail (1/4)	Not	5bv	Assessment was evaluated because samples used to complete assessment weren’t collected in the last five years.

Class BCW1 – Trout Natural Reproduction:

Based on the January 2024 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 Binomial 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

Monitoring and Methods

Assessment Key Dates

4/3/2012

Monitoring Start

10/7/2014

Monitoring End

1/1/2024

Biological Monitoring

8/15/2013

Biological Monitoring

9/10/2013

Biological Monitoring

8/4/2014

Biological Monitoring

9/15/2014

Biological Monitoring

7/2/2013

Monitoring Start

9/15/2014

Monitoring End

Methods

120

Surveys of fish and game biologists/other professionals

150

Monitoring data more than 5 years old

200

Physical/Chemical Monitoring

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

330

Fish surveys

420

Indicator bacteria monitoring