Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Ballard Creek IA 03-SSK-952

mouth to unnamed tributary in S15 T82N R24W Story 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 8:12:55 AM
Updated
12/29/2023 11:03:21 AM
Use Support
Class A1
Recreation - Primary contact
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
Aquatic Life - Warm Water Type 2
WINOFI
Impairment Code
3b-c - Use potentially biologically impaired based on calibrated IBI metrics.
Cause Magnitude
Slight
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2016
Impairment Rationale
Potential Impairment
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” based on E. coli monitoring data. The Class BWW2 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

Prairie Rivers/City of Ames

26

WQ

CY 2020-2022

99990159

Ballard Creek

Iowa DNR

6

BIO

See Below

637

Ballard Creek

Cambridge


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

99990159

26

2/4/5

554

255

585

YES

2 / NA

2 / NA

3 / NA

NA

Evaluated

WINOFI

The bacteria samples were collected by the Prairie Rivers Watershed Group and Story County Conservation with the analyses conducted by the City of Ames. Since the data were not collected under a DNR-approved quality assurance plan, the assessment was considered "evaluated" instead of "monitored." According to Iowa DNR’s assessment/listing methodology, impairments based on “evaluated” assessments are of lesser confidence and are not appropriate for Section 303(d) listing (Category 5 of the Integrated Report). The Iowa DNR does, however, consider these impairments as appropriate for listing under Category 3b of the Integrated Report (waters potentially impaired and in need of further investigation).


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

637

7/18/07

24

47b

MS/WW

Surber

65

Good

62

Pass

637

7/18/07

24

47b

MS/WW

ArtSub

61

Good

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

637

8/2/13

24

47b

MS/WW

No

26

Fair

32

Fail

637

7/18/07

24

47b

MS/WW

No

43

Fair

32

Pass


Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Fail (1/2)

WINOFI

Fish

Evaluated

Fail (1/2)

WINOFI

Assessment was evaluated because it included

Overall

Evaluated

Fail

WINOFI

3bc

samples not collected in a recent five-year period.



Monitoring and Methods
Assessment Key Dates
7/18/2007
Biological Monitoring
8/2/2013
Biological Monitoring
5/20/2020
Monitoring Start
7/27/2022
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