Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Unnamed Tributary to West Fork Little Sioux River IA 06-LSR-1835

mouth in T92N R42W Sec1 NW (Cherokee Co.) to headwaters

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 8:13:26 AM
Updated
1/16/2024 3:42:03 PM
Use Support
Class A1
Recreation - Primary contact
Not Assessed
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 BWW1 use was assessed as “WINOFI” based on biological sampling data. 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

2021

348

Unnamed Tributary to West Fork Little Sioux River

Iowa DNR

6

BIO

See Below

348

Unnamed Tributary to West Fork Little Sioux River

Marcus (REMAP #77)


Presumptive Class A1 - No Data

Presumptive Class BWW1 - Biological Sampling:


Benthic Macroinvertebrates:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage/Thermal

BM Sample Gear

BMIBI score

BMIBI Class

47a BMIBI BIT

BMIBI Pass/Fail

348

7/6/21

4.4

47a

MO/WW

ArtSub

34

Fair

54

Fail


Fish:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage/Thermal

Riffle Stream?

FIBI score

FIBI Class

47a FIBI BIT

FIBI Pass/Fail

348

7/6/21

4.4

47a

MO/WW

NA

1

Poor

43

Fail


Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Fail (0/1)

WINOFI

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

Fish

Evaluated

Fail (0/1)

WINOFI

the drainage area of the sample site was smaller than the calibrated

Overall

Evaluated

Fail

WINOFI

3bu

range, and sample was collected earlier than July 15.


Presumptive Class BWW1- Continuous DO Monitoring:

Site ID

Data Source ID

# Days Monitoring (2021)

DO Criteria Type

# 2021 violations / Violations needed for impairment

Violates Annual Significantly >10% Rule?

Assessment Type

Support Level

24 hr

1/4

No

348

6

16

16 hr

0/4

No

Evaluated

Full




Monitoring and Methods
Assessment Key Dates
7/6/2021
Biological Monitoring
6/21/2021
Monitoring Start
7/6/2022
Monitoring End
Methods
200
Physical/Chemical Monitoring
315
Regional reference site approach
320
Benthic macroinvertebrate surveys
330
Fish surveys