Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Little Wolf Creek IA 02-CED-1903

mouth (NW1/4 S5 T85N R16W Tama Co.) to headwaters (Grundy Co.)

Cycle
2024
Release Status
Final
Overall IR
3 - Insufficient data exist to determine whether any designated uses are met.
Trend
Unknown
Created
11/1/2023 8:13:04 AM
Updated
12/28/2023 11:16:09 AM
Use Support
Class A1
Recreation - Primary contact
WINOFI
Impairment Code
3b - Use potentially impaired based on an evaluated assessment.
Cause Magnitude
Slight
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2022
Impairment Rationale
Geometric mean criterion exceeded
Data Source
Watershed project monitoring
Class BWW1
Aquatic Life - Warm Water Type 1
WINOFI
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
2006
Impairment Rationale
Low Biotic Index
Data Source
Biological monitoring: Iowa DNR WQMA
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The presumptive Class A1 use was assessed as "WINOFI" due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The presumptive Class BWW1 use was assessed as “WINOFI” based on biological sampling data.

Assessment Explanation

Data Sources:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

CRWQ

23

WQ

CY 2020-2022

99990065

Little Wolf Creek

Iowa DNR

6

BIO

See Below

421

Little Wolf Creek

Gladbrook (REMAP #232)


Presumptive Class A1 - Indicator Bacteria:

Site ID

Data Source ID

# Samples per Year (2020/ 2021/2022)

2020 Geometric Mean

2021 Geometric Mean

2022 Geometric Mean

Violates Annual Geometric Mean?

# 2020 SSM violations / SSM Violations needed for impairment

# 2021 SSM violations / SSM Violations needed for impairment

# 2022 SSM violations / SSM Violations needed for impairment

Violates Annual SSM Significantly >10% Rule?

Assessment Type

Support Level

99990065

23

5/5/5

174

100

138

YES

2 / NA

2 / NA

2 / NA

NA

Eval

WINOFI


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

99990065

23

14 / 3

7.78

8.57

8.02

0

4

NO

Mon

Full


Class BWW1 - 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

99990065

23

Chloride

15 / 3

12.5

19.3

14.8

NA

0 / 0

4

NO

Mon

Full

99990065

23

Dissolved Oxygen

14 / 3

4.3

11.8

8.3

1

NA / NA

4

NO

Mon

Full

99990065

23

pH

14 / 3

7.78

8.57

8.02

0

NA / NA

4

NO

Mon

Full

99990065

23

Sulfate

15 / 3

9.4

14.6

11.9

0

NA / NA

4

NO

Mon

Full

99990065

23

Temperature

15 / 3

5.1

21.8

15.4

0

NA / NA

4

NO

Mon

Full


Presumptive Class BWW1 - Biological Sampling:


Benthic Macroinvertebrates:

Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

BM Sample Gear

BMIBI score

BMIBI Class

47c BMIBI BIT

BMIBI Pass/Fail

421

8/12/04

22

47c

MS

Hess

56

Good

70

Fail


Fish:

Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

Riffle Stream?

FIBI score

FIBI Class

47c FIBI BIT

FIBI Pass/Fail

421

8/12/04

22

47c

MS

Yes

48

Fair

65

Fail


Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Fail (0/1)

WINOFI

Fish

Evaluated

Fail (0/1)

WINOFI

Assessment was evaluated because it was based on a single sample and

Overall

Evaluated

Fail

WINOFI

3bu

the drainage area of the site was smaller than the calibrated range.

Monitoring and Methods
Assessment Key Dates
8/12/2004
Biological Monitoring
6/3/2020
Monitoring Start
8/22/2022
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