Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Clark Creek IA 01-UIA-6437

from mouth in S31 T100N R4W Allamakee Co. to headwaters (T99N R4W Sec21 Allamakee 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 8:13:35 AM
Updated
1/3/2024 2:04:33 PM
Use Support
Class A1
Recreation - Primary contact
Not Assessed
Class BWW1
Aquatic Life - Warm Water Type 1
Not Supported
Impairment Code
3b-u - Use potentially biologically impaired based on uncalibrated IBI metrics.
Cause Magnitude
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2016
Impairment Rationale
Potential Impairment
Data Source
Biological monitoring: Iowa DNR WQMA
Support Level
Not Supported
Impairment Code
5b - Biological impairment or pollutant-caused fish kill - unknown source. No administrative action.
Cause Magnitude
Moderate
Status
Continuing
Source
Agriculture: Animal Feeding Operations
Source Confidence
High
Cycle Added
2016
Impairment Rationale
Pollutant-caused fish kill
Data Source
Fish kill investigation: Iowa DNR
TMDL Priority
Tier IV
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The presumptive Class BWW1 use was assessed as "not supported" based on biological sampling data and due to a fish kill investigation. 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

781

Clark Creek

New Albin


Presumptive Class A1 - No Data


Presumptive Class BWW1 – Fish kill Assessment:

The presumptive Class BWW1 aquatic life use assessment based on the 2015 fish kill placed this segment in Category 5b. The fish kill was caused by a “pollutant” or was suspected to be caused by a “pollutant”; therefore, the presumptive Class BWW1 use was considered impaired. Because the source of the pollutant was not identified and/or the enforcement actions taken against the responsible party have not been resolved, the presumptive Class BWW1 use was placed in Category 5b. Due to uncertainty regarding the recovery of the aquatic life following the fish kill, any existing fish kill 5b impairment will remain in Category 5b until more recent sampling has shown recovery of the aquatic community or the responsible party has paid restitution.

Details about the 2015 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/903


Presumptive Class BWW1 - 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

781

9/22/14

7.0

52b

MS

Hess

58

Good

61

Pass*


Fish:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

Riffle Stream?

FIBI score

FIBI Class

52b FIBI BIT

FIBI Pass/Fail

781

9/22/14

7.0

52b

MS

NA

27

Fair

52

Fail


Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Pass (1/1)

Full

*The BMIBI passed after 8 point UAV was applied to single sample.

Fish

Evaluated

Fail (0/1)

WINOFI

Assessment was evaluated because the drainage area of the

Overall

Evaluated

Fail

WINOFI

3bu

sample site was smaller than the calibrated range.

Monitoring and Methods
Assessment Key Dates
9/22/2014
Biological Monitoring
10/12/2015
Fish Kill
Methods
140
Incidence of spills and/or fish kills
150
Monitoring data more than 5 years old
315
Regional reference site approach
320
Benthic macroinvertebrate surveys
330
Fish surveys