Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Hickory Creek IA 01-YEL-441

mouth (NE 1/4 S23 T96N R5W Allamakee Co.) to south line of S28 T96N R5W Allamakee Co.

Cycle
2024
Release Status
Final
Overall IR
4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
Trend
Unknown
Created
11/1/2023 8:13:48 AM
Updated
2/6/2024 7:34:33 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
Watershed project monitoring
Class A2
Recreation - Secondary contact
Fully Supported
Class BCW1
Aquatic Life - Cold Water Type 1
Fully Supported
Class HH
Human Health -
Not Assessed
Impairment Delistings
Cycle Added Class Cause Data Source Rationale
2008 Class BCW1 Organic Enrichment: Low Dissolved Oxygen 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 A2 use was assessed as “fully supported” based on pH monitoring data. The Class BCW1 use was assessed as "fully supported" based on water quality monitoring and on the trout reproduction in Iowa streams summary prepared by the DNR Fisheries Bureau. All other designated uses were “not assessed.” Note: A TMDL for the bacterial impairment for streams in the Yellow River basin was prepared by Iowa DNR in 2012 and was approved by U.S. EPA in February 2013. Due to completion of the TMDL, the Integrated Report category for the Class A1 recreational use was changed from 5p (impaired; TMDL needed) to 4a (impaired; TMDL approved).

Assessment Explanation

Data Sources:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

Iowa DNR

6

WQ

CY 2008-2009, CY 2021-2022

15030007

Hickory Creek at Hickory Creek Rd.


Presumptive Class A1 - Indicator Bacteria: 2008-2009

Site ID

Data Source ID

# Samples / # Years

2008 Geometric Mean

2009 Geometric Mean

Annual Geometric Mean Violation

# Violations

% Violations

Significantly >10% Violations

Assessment Type

Support Level

15030007

6

15 / 2

696

422

Yes

13

86%

Yes

Evaluated

Not


Class A2 – Indicator Bacteria: No Data


Presumptive Class A1 and Class A2 – pH: 2021-2022

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

15030007

6

10 / 2

7.57

8.37

8

0

3

NO

Mon

Full


Class BCW1 - Binomial Parameters: 2021-2022

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

15030007

6

Dissolved Oxygen

10 / 2

10.17

13.99

11.04

0

NA / NA

3

NO

Mon

Full

15030007

6

pH

10 / 2

7.57

8.37

8

0

NA / NA

3

NO

Mon

Full

15030007

6

Temperature

10 / 2

7.75

14.72

12.02

0

NA / NA

3

NO

Mon

Full


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 Hickory 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
5/20/2004
Monitoring Start
9/17/2009
Monitoring End
1/1/2024
Biological Monitoring
1/1/2012
TMDL Completed
5/27/2021
Monitoring Start
9/13/2022
Monitoring End
Methods
120
Surveys of fish and game biologists/other professionals
150
Monitoring data more than 5 years old
200
Physical/Chemical Monitoring
330
Fish surveys
420
Indicator bacteria monitoring