Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Stony Creek IA 06-LSR-1644

mo to trib S27T98NR38W Dickinson Co.

Cycle
2022
Release Status
Final
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Unknown
Created
12/30/2021 2:35:07 PM
Updated
1/7/2022 12:09:01 PM
Use Support
Class A1
Recreation - Primary contact
Not Assessed
Class BWW2
Aquatic Life - Warm Water Type 2
Not Supported
Impairment Code
3b - Use potentially impaired based on an evaluated assessment.
Cause Magnitude
Moderate
Status
Continuing
Source
Spills/Dumping: Spills
Source Confidence
High
Cycle Added
2016
Impairment Rationale
Pollutant-caused fish kill
Data Source
Fish kill investigation: Iowa DNR
Support Level
Not Supported
Impairment Code
5b-t - Biological - tentative
Cause Magnitude
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2008
Impairment Rationale
Low Biotic Index
Data Source
Biological monitoring: Iowa DNR WQMA
TMDL Priority
Tier IV
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The Class BWW2 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

480

Stony Creek

Everly – REMAP #148


Presumptive Class A1 - No Data


Class BWW2 - 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

480

8/30/05

59

47a

MO/WW

Art Sub

28

Poor

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

480

8/30/05

59

47a

MO/WW

NA

34

Fair

43

Fail


Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Fail (0/1)

Not

Fish

Evaluated

Fail (0/1)

Not

Overall

Evaluated

Fail

Not

5bt

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


Class BWW2 - Fish kill Assessment:

The Class BWW2 use previously resided in Category 4d based on the assessment developed for the 2015 fish kill. Because no additional fish kills were reported in this segment for at least five years post fish kill (2020), the Category for the fish kill assessment was changed from 4d to 3b (potentially impaired). DNR believes that any impact from the fish kill from which the impairment was based has likely dissipated. If no additional fish kills are reported in the segment for an additional five-year period (2025), the Category will be changed from 3b to 3a (not assessed).


Details about the 2015 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/889

Monitoring and Methods
Assessment Key Dates
8/30/2005
Biological Monitoring
9/29/2015
Fish Kill
Methods
120
Surveys of fish and game biologists/other professionals
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