Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Yellow River IA 01-YEL-437

from N. Fk. Yellow R. (S13 T96N R7W Allamakee Co.) to confluence with unnamed tributary in SE 1/4 S8 T96N R7W Winneshiek Co.

Cycle
2024
Release Status
Final
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Unknown
Created
11/1/2023 8:12:43 AM
Updated
12/14/2023 8:07:45 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
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2008
Impairment Rationale
Geometric mean criterion exceeded
Data Source
Special project/study: Iowa DNR
Class BWW2
Aquatic Life - Warm Water Type 2
Not Supported
Support Level
Not Supported
Impairment Code
5b-t - Biological - tentative
Cause Magnitude
Slight
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2004
Impairment Rationale
Low Biotic Index
Data Source
Biological monitoring: Iowa DNR WQMA
TMDL Priority
Tier IV
Impairment Delistings
Cycle Added Class Cause Data Source Rationale
2016 Class A1 pH Ambient monitoring: Iowa DNR-rivers New data: WQ improvement (chemical / physical / bacterial)
2014 Class BWW2 pH Ambient monitoring: Iowa DNR-rivers New data: WQ improvement (chemical / physical / bacterial)
Documentation
Assessment Summary

The presumptive Class A1 use was assessed as “not supported” due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BWW2 use was assessed as “not supported” based on biological sampling data. Note: A TMDL for the bacterial impairment for Yellow River basin streams was prepared by Iowa 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

WQ

CY2014 & CY2021-2022

11960006

Yellow River near Castalia

Site YeRi3

Iowa DNR

6

WQ

CY2014

15960002

Yellow River at 107 Ave

Iowa DNR

6

BIO

See Below

156

Yellow River

Site 1 – Most Upstream Site

Iowa DNR

6

BIO

See Below

1124

Yellow River

Corner of 120 Ave and 111 Ave


Presumptive Class A1 - Indicator Bacteria: 2014

Site ID

Data Source ID

# Samples / # Years

2014 Geometric Mean

Annual Geometric Mean Violation

# Violations

% Violations

Significantly >10% Violations

Assessment Type

Support Level

11960006

6

20 / 1

601

Yes

15

75%

Yes

Evaluated

Not

15960002

6

20 / 1

1661

Yes

17

85%

Yes

Evaluated

Not


Presumptive Class A1 – pH:

Site ID

Data Source ID

# Samples / # Years

Minimum Value

Maximum Value

Mean Value

# Violations

Violations needed for impairment

Violates Significantly >10% Rule?

Assessment Type

Support Level

11960006

6

9 / 2

7.81

8.12

8

0

3

NO

Mon

Full


Class BWW2 - Binomial Parameters:

Site ID

Data Source ID

Parameter Name

# Samples / # Years

Minimum Value

Maximum Value

Mean Value

# Violations

# Acute / Chronic Violations

Violations needed for impairment

Violates Significantly >10% Rule?

Assessment Type

Support Level

11960006

6

Dissolved Oxygen

9 / 2

8.43

12.61

10.1

0

NA / NA

3

NO

Mon

Full

11960006

6

pH

9 / 2

7.81

8.12

8

0

NA / NA

3

NO

Mon

Full

11960006

6

Temperature

9 / 2

6.091

21.484

15.344

0

NA / NA

3

NO

Mon

Full


Class BWW2 - Biological Sampling:


Benthic Macroinvertebrates:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

BM Sample Gear

BMIBI score

BMIBI Class

52b BMIBI BIT

BMIBI Pass/Fail

156

9/26/22

18.7

52b

MS/WW

Hess

55

Fair

61

Fail

1124

9/26/22

14.6

52b

MS/WW

Hess

60

Good

61

Fail


Fish:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

Riffle Stream?

FIBI score

FIBI Class

52b FIBI BIT

FIBI Pass/Fail

156

9/26/22

18.7

52b

MS/WW

NA

58

Good

52

Pass

1124

9/27/22

14.6

52b

MS/WW

NA

59

Good

52

Pass


Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Fail (0/2)

Not

Fish

Evaluated

Pass (2/2)

Full

Assessment was evaluated because the samples included

Overall

Evaluated

Fail

Not

5bt

in the assessment were collected in the same year.



Monitoring and Methods
Assessment Key Dates
9/26/2022
Biological Monitoring
4/24/2014
Monitoring Start
10/8/2014
Monitoring End
9/27/2022
Biological Monitoring
2/1/2013
TMDL Completed
5/21/2021
Monitoring Start
9/12/2022
Monitoring End
Methods
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