Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Dousman Creek IA 01-YEL-438

mouth (S33 T96N R3W Allamakee Co.) to Allamakee-Clayton county line.

Cycle
2022
Release Status
Final
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Unknown
Created
12/16/2021 9:21:54 AM
Updated
12/16/2021 9:50:43 AM
Use Support
Class A1
Recreation - Primary contact
Not Supported
Support Level
Not Supported
Impairment Code
4a - Pollutant-caused impairment. TMDL has been completed.
Cause Magnitude
Slight
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2008
Impairment Rationale
Geometric mean criterion exceeded
Data Source
Watershed project monitoring
Class A2
Recreation - Secondary contact
Fully Supported
Class BCW1
Aquatic Life - Cold Water Type 1
Not Supported
Support Level
Not Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2008
Impairment Rationale
Significantly > 10% of samples fail to meet criterion
Data Source
Watershed project monitoring
TMDL Priority
Tier IV
Class HH
Human Health -
Not Assessed
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The presumptive Class A1 use was assessed as “not supported” due to levels of indicator bacteria that exceeded state water quality criteria. The Class BCW1 use was assessed as "not supported" based on levels of dissolved oxygen that violated state water quality criteria. All other designated uses were "not assessed." Note: A TMDL for the bacterial impairment for Yellow River basin streams was prepared by DNR in 2012 and was approved by U.S. EPA in February 2013. Due to TMDL completion, the Integrated Report category for the Class A1 recreational use was changed from 5p to 4a.

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

352

Dousman Creek

Ion

Iowa DNR

6

WQ

CY 2004-2006, CY 2006-2008

15030004

Dousman Creek

YRWP


Presumptive Class A1 – Indicator Bacteria: 2006-2008

Site ID

Data Source ID

# Samples / # Years

2006 Geometric Mean

2007 Geometric Mean

2008 Geometric Mean

Annual Geometric Mean Violation

# Violations

% Violations

Significantly >10% Violations

Assessment Type

Support Level

15030004

6

34 / 3

246

148

322

Yes

15

44%

Yes

Evaluated

Not

Class A2 – Indicator Bacteria: 2006-2008

Site ID

Data Source ID

# Samples / # Years

2006 Geometric Mean

2007 Geometric Mean

2008 Geometric Mean

Annual Geometric Mean Violation

# Violations

% Violations

Significantly >10% Violations

Assessment Type

Support Level

15030004

6

34 / 3

246

148

322

No

6

17%

No

Evaluated

Full


Class BCW1 – Dissolved Oxygen: 2004-2006

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

15030004

6

Dissolved oxygen

75 / 3

NA

NA

NA

20 / 0

27% / 0%

Yes

Evaluated

Not


Class BCW1 - Biological Sampling:


Benthic Macroinvertebrates:

Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

BM Sample Gear

CBI score

CBI Class

CBI BIT

CBI Pass/ Fail

352

8/7/19

7.4

52b

MS

Hess

50

NA

60

Fail

352

8/12/15

7.4

52b

MS

Hess

66

NA

60

Pass

352

7/18/03

7.4

52b

MS

Hess

60

NA

60

Pass

Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Pass (2/3)

Full

Assessment was evaluated because some of the samples used to complete

Overall

Evaluated

Pass

Full

1

the assessment were greater than five years old.


Class BCW1 - Trout Natural Reproduction:

Based on the January 2021 trout reproduction in Iowa streams summary prepared by the DNR Fisheries Bureau, the Class BCW1 coldwater aquatic life use of Dousman Creek 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 HH – No Data

Monitoring and Methods
Assessment Key Dates
1/1/2021
Biological Monitoring
5/20/2004
Non-fixed Monitoring Start Date
11/16/2006
Non-fixed Monitoring End Date
2/1/2006
Non-fixed Monitoring Start Date
9/30/2008
Non-fixed Monitoring End Date
8/12/2015
Biological Monitoring
2/25/2013
TMDL Completed
8/7/2019
Biological Monitoring
7/18/2003
Biological Monitoring
Methods
120
Surveys of fish and game biologists/other professionals
150
Monitoring data more than 5 years old
220
Non-fixed station physical/chemical monitoring (conventional pollutant only)
315
Regional reference site approach
320
Benthic macroinvertebrate surveys
330
Fish surveys
380
Quantitative physical habitat assessment
420
Indicator bacteria monitoring