Iowa DNR
ADBNet

Water Quality Assessments

Impaired Waters List

Long Dick Creek IA 03-SSK-2007

N. line of S34 (SE1/4) T86N R23W Hamilton Co to headwaters in NE1/4 S8 T87N R23W Hamilton Co.

Assessment Cycle
2024
Release Status
Pending
Data Collection Period
Overall IR Category
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Unknown
Created
12/8/2023 1:52:59 PM
Updated
2/2/2024 7:11:04 AM
Assessment conducted in accordance with Iowa's 2024 IR methodology.
Use Support
Class A1
Not Supported
Bacteria: Indicator Bacteria- E. coli
Support Level
Not Supported
Impairment Code
5p - Impairment occurs on a waterbody with a presumptive A1 or B(WW1) use.
Cause Magnitude
Slight
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2010
Impairment Rationale
Single-sample maximum criterion exceeded in significantly > 10% of samples
Data Source
TMDL monitoring: Iowa DNR
TMDL Priority
Tier IV
Class BWW1
WINOFI
Biological: low fish IBI
Support Level
Water in Need of Further Investigation (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
2010
Impairment Rationale
Low Biotic Index
Data Source
Biological monitoring: Iowa DNR WQMA
Impairment Delistings
Cycle Added Class Cause Data Source Rationale
2006 Class BWW1 Fish Kill: Caused By Animal Waste Biological monitoring: Iowa DNR fish kill follow-up New data: recovery of fish community from pollutant-caused fish kill
2014 Class BWW1 Fish Kill: Caused By Pesticides Biological monitoring: Iowa DNR fish kill follow-up New data: recovery of fish community from pollutant-caused fish kill
Documentation
Assessment Summary

The presumptive Class A1 use was assessed as "not supported" 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 historical biological sampling. However, biological sampling data collected in 2022 showed recovery of the fish community in this segment from the fish kills. Based on the 2022 fish sampling data, the 5b fish kill impairments were de-listed.

Assessment Explanation

Data Sources:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

Iowa DNR

6

WQ

CY 2008 – 2009

11400004

Long Dick Creek near Ellsworth

Site ldc-2

Iowa DNR

6

BIO

See Below

691

Long Dick Creek

Ellsworth – LDC2


Presumptive Class A1 - Indicator Bacteria: Historical

Site ID

Data Source ID

# Samples / # Years

2008 Geometric Mean

2009 Geometric Mean

Annual Geometric Mean Violation

# Violations

% Violations

Significantly >10% Violations

Assessment Type

Support Level

11400004

6

26 / 2

369

175

Yes

15

58%

Yes

Evaluated

Not


Presumptive Class BWW1 - Biological Sampling:


Benthic Macroinvertebrates:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

BM Sample Gear

BMIBI score

BMIBI Class

47b BMIBI BIT

BMIBI Pass/Fail

691

10/6/08

16

47b

MS

Art Sub

71

Good

62

Pass


Fish:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

Riffle Stream?

FIBI score

FIBI Class

47b FIBI BIT

FIBI Pass/Fail

691

10/6/08

16

47b

MS

Yes

24

Poor

53

Fail


Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Pass (1/1)

Full

Fish

Evaluated

Fail (0/1)

WINOFI

Assessment was evaluated because the drainage area of the

Overall

Evaluated

Fail

WINOFI

3bu

site was smaller than the calibrated range.


Presumptive Class BWW1 – Fish kill Assessment:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage/ Thermal

Fish per mile

47b REMAP 25 % fish per mile

>47b REMAP 25 % fish per mile?

2024 IR 47b expected fish taxa

Fish Taxa Present % (>50% to pass)

1389

08/25/22

21.9

47b

MS/WW

9810

1362

Yes (Pass)

11/12

91.6% (Pass)

The presumptive Class BWW1 use previously resided in Category 5b based on 2004 and 2011 fish kills. This segment’s fish community was sampled in 2022 as part of the DNR fish kill follow-up sampling program. The results from this follow-up sampling and comparison to ecoregion averages suggest that the fish community of this segment is similar to non-fish kill impacted streams. Based on the fish kill follow-up sampling results, the category for the fish kill assessment was changed from 5b to 3a (not assessed).


More details about the 2011 fish kill can be found here:https://programs.iowadnr.gov/fishkill/Events/834

More details about the 2004 fish kill can be found here:https://programs.iowadnr.gov/fishkill/Events/599



Monitoring and Methods
Assessment Key Dates
8/4/2011 Fish Kill
7/28/2009 Monitoring End
10/6/2008 Biological Monitoring
1/7/2008 Monitoring Start
4/19/2004 Fish Kill
8/25/2022 Biological Monitoring
Methods
140 Incidence of spills and/or fish kills
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