Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Turkey River IA 01-TRK-152

from bridge crossing at Elgin (S13 T94N R7 Fayette Co.) to confluence with Little Turkey R near Eldorado (S18 T95N R8W Fayette Co.).

This is a DRAFT assessment
Draft assessments may change without notice
Cycle
2026
Current Phase
Public Comment
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Stable
Created
10/27/2025 3:08:48 PM
Updated
12/19/2025 2:39:00 PM
Use Support
Class A1
Recreation - Primary contact
Not Supported
Support Level
Not Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
Slight
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2014
Impairment Rationale
Geometric mean criterion exceeded
Data Source
Watershed project monitoring
TMDL Priority
Tier III
Class BWW1
Aquatic Life - Warm Water Type 1
Not Assessed
Class HH
Human Health -
Not Assessed
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The Class A1 use was assessed as "not supported” due to levels of indicator bacteria that exceeded Iowa water quality criteria. 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

WQ

CY 2012-2014

15330010

Turkey River at Great River Road/B40

TR50

Iowa DNR

6

WQ

CY 2012-2014

15330011

Turkey River at Great River Road/B40

TR60


Class A1 - 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

15330010

6

24 / 3

107

2062

95

Yes

10

42%

Yes

Evaluated

Not

15330011

6

24 / 3

287

824

211

Yes

11

46%

Yes

Evaluated

Not


Class BWW1 - No Data

Monitoring and Methods
Assessment Key Dates
4/4/2012
Monitoring Start
11/5/2014
Monitoring End
Methods
150
Monitoring data more than 5 years old
420
Indicator bacteria monitoring