Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

South Beaver Creek IA 02-CED-561

mouth (S25 T90N R17W Butler Co.) to confluence with Middle Fork South Beaver Cr. in S28T89R17W Grundy Co.

Cycle
2022
Release Status
Final
Overall IR
2 - Some of the designated uses are met but there is insufficient data to determine if remaining designated uses are met.
Trend
Unknown
Created
12/15/2021 1:58:28 PM
Updated
1/13/2022 9:23:02 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
N/A
Cycle Added
2022
Impairment Rationale
Geometric mean criterion exceeded
Data Source
Watershed project monitoring
Class BWW2
Aquatic Life - Warm Water Type 2
Fully Supported
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The presumptive Class A1 use was assessed as “WINOFI” due to violations of Iowa water quality criteria for indicator bacteria (E. coli). The Class BWW2 use was assessed as "fully supported" based on biological sampling data and water quality monitoring data.

Assessment Explanation

Data Sources:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

CRWQ

23

WQ

CY 2018-2020

99990077

South Beaver Creek

Iowa DNR

6

BIO

See Below

54

South Beaver Creek

Parkersburg

Presumptive Class A1 - Indicator Bacteria:

Site ID

Data Source ID

# Samples per Year (2018/ 2019/2020)

2018 Geometric Mean

2019 Geometric Mean

2020 Geometric Mean

Violates Annual Geometric Mean?

# 2018 SSM violations / SSM Violations needed for impairment

# 2019 SSM violations / SSM Violations needed for impairment

# 2020 SSM violations / SSM Violations needed for impairment

Violates Annual SSM Significantly >10% Rule?

Assessment Type

Support Level

99990077

23

5/5/5

849

502

417

YES

4 / NA

4 / NA

4 / NA

NA

Evaluated

WINOFI

Class A – pH:

Site ID

Data Source ID

# Samples / # Years

Minimum Value

Maximum Value

Mean Value

# Violations

Violations needed for impairment

Violates Significantly >10% Rule?

Assessment Type

Support Level

99990077

23

14 / 3

7.33

8.26

7.95

0

4

NO

Monitored

Full

Class BWW2 - Conventional Parameters:

Site ID

Data Source ID

Parameter Name

# Samples / # Years

Minimum Value

Maximum Value

Mean Value

# Violations

# Acute / Chronic Violations

Violations needed for impairment

Violates Significantly >10% Rule?

Assessment Type

Support Level

99990077

23

Chloride

15 / 3

15.7

22.9

18.9

NA

0 / 0

4

NO

Monitored

Full

99990077

23

Dissolved Oxygen

15 / 3

7.1

11.1

8.3

0

NA / NA

4

NO

Monitored

Full

99990077

23

pH

14 / 3

7.33

8.26

7.95

0

NA / NA

4

NO

Monitored

Full

99990077

23

Sulfate

15 / 3

10.4

28.1

18.6

0

NA / NA

4

NO

Monitored

Full

99990077

23

Temperature

15 / 3

7.9

22.6

18

0

NA / NA

4

NO

Monitored

Full


Class BWW2 - Biological Sampling:


Benthic Macroinvertebrates:

Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

BM Sample Gear

BMIBI score

BMIBI Class

47c BMIBI BIT

BMIBI Pass/ Fail

54

8/19/19

115.6

47c

MS

Art Sub

78

Excellent

70

Pass

54

9/10/14

115.6

47c

MS

Art Sub

41

Fair

70

Fail

54

8/13/01

115.6

47c

MS

Art Sub

74

Good

70

Pass

Fish:

Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

Riffle Stream?

FIBI score

FIBI Class

47c FIBI BIT

FIBI Pass/ Fail

54

8/19/19

115.6

47c

MS

No

58

Good

44

Pass

54

9/10/14

115.6

47c

MS

No

63

Good

44

Pass

Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Pass (2/3)

Full

Fish

Evaluated

Pass (2/2)

Full

1

Assessment was evaluated because it included samples not collected in

Overall

Evaluated

Pass

Full

the last five years.


Monitoring and Methods
Assessment Key Dates
8/19/2019
Biological Monitoring
8/13/2001
Biological Monitoring
9/10/2014
Biological Monitoring
5/17/2018
Non-fixed Monitoring Start Date
9/28/2020
Non-fixed Monitoring End Date
Methods
150
Monitoring data more than 5 years old
220
Non-fixed station physical/chemical monitoring (conventional pollutant only)
315
Regional reference site approach
320
Benthic macroinvertebrate surveys
330
Fish surveys
380
Quantitative physical habitat assessment
420
Indicator bacteria monitoring