Iowa DNR
ADBNet

Water Quality Assessments

Impaired Waters List

Long Dick Creek IA 03-SSK-960

mouth (S18 T85N R23W Story Co.) to N. line of S34 T86N 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
11/1/2023 8:12:56 AM
Updated
12/29/2023 12:13:44 PM
Assessment conducted in accordance with Iowa's 2024 IR methodology.
Use Support
Class A1
Presumptive Use
WINOFI
Bacteria: Indicator Bacteria- E. coli
Support Level
Water in Need of Further Investigation (WINOFI)
Impairment Code
3b - Use potentially impaired based on an evaluated assessment.
Cause Magnitude
Moderate
Status
New
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2024
Impairment Rationale
Potential Impairment
Data Source
Special project/study
Class BWW2
Not Supported
Biological: low aquatic macroinvertebrate IBI
Support Level
Not Supported
Impairment Code
5b-t - Biological - tentative
Cause Magnitude
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2004
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 presumptive Class A1 use was assessed as "WINOFI" based on E. coli monitoring data. The Class BWW2 use was assessed as “not supported” based on biological sampling data.

Assessment Explanation

Data Sources:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

Prairie Rivers/City of Ames

26

WQ

CY 2020-2022

99990167

Long Dick Creek

Iowa DNR

6

BIO

See Below

115

Long Dick Creek

Roland – LDC1

Iowa DNR

6

BIO

See Below

116

Long Dick Creek

Roland – Old LDC2


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

99990167

26

7/6/8

487

392

430

YES

6 / 3

4 / NA

6 / 3

YES

Evaluated

WINOFI


Class BWW2 - Biological Sampling:

Benthic Macroinvertebrates:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage/Thermal

BM Sample Gear

BMIBI score

BMIBI Class

47b BMIBI BIT

BMIBI Pass/Fail

115

9/25/08

32

47b

MS/WW

ArtSub

40

Fair

62

Fail

116

9/24/03

26

47b

MS/WW

Surb

44

Fair

62

Fail

115

9/23/03

32

47b

MS/WW

ArtSub

33

Fair

62

Fail


Fish:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage/Thermal

Riffle Stream?

FIBI score

FIBI Class

47b FIBI BIT

FIBI Pass/Fail

115

9/25/08

32

47b

MS/WW

No

44

Fair

32

Pass

116

9/24/03

26

47b

MS/WW

Yes

33

Fair

53

Fail

115

9/23/03

32

47b

MS/WW

No

34

Fair

32

Pass


Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Fail (0/3)

Not

Fish

Evaluated

Pass (2/3)

Full

Assessment was evaluated because it included samples

Overall

Evaluated

Fail

Not

5bt

not collected in a recent five-year period.

Monitoring and Methods
Assessment Key Dates
9/23/2003 Biological Monitoring
9/24/2003 Biological Monitoring
9/25/2008 Biological Monitoring
4/15/2020 Monitoring Start
10/19/2022 Monitoring End
Methods
150 Monitoring data more than 5 years old
315 Regional reference site approach
320 Benthic macroinvertebrate surveys
330 Fish surveys
420 Indicator bacteria monitoring
860 Other Agencies/Organizations provided monitoring data