Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Lime Creek IA 02-CED-524

mouth (SW 1/4 S4 T86N R10W Benton Co.) to confluence with unnamed tributary in S1 T87N R10W Buchanan Co.

This is a DRAFT assessment
Draft assessments may change without notice
Cycle
2026
Current Phase
Public Comment
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Declining
Trend Comment
Benthic macroinvertebrate (BMIBI) scores have a downward trend.
Created
10/27/2025 3:09:26 PM
Updated
2/5/2026 9:23:25 AM
Use Support
Class A1
Recreation - Primary contact
Not Supported
Support Level
Not Supported
Impairment Code
5p - Impairment occurs on a waterbody with a presumptive A1 or B(WW1) use.
Cause Magnitude
High
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2014
Impairment Rationale
Geometric mean criterion exceeded
Data Source
Special project/study
TMDL Priority
Tier III
Class BWW1
Aquatic Life - Warm Water Type 1
WINOFI
Impairment Code
3b-c - Use potentially biologically impaired based on calibrated IBI metrics.
Cause Magnitude
Slight
Status
New
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2026
Impairment Rationale
Potential Impairment
Data Source
Biological monitoring: Iowa DNR WQMA
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
2026
Impairment Rationale
Potential Impairment
Data Source
Watershed project monitoring
Class HH
Human Health -
Not Assessed
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The presumptive Class A1 use remains assessed as "not supported" due to levels of indicator bacteria (E. coli) that violated state water quality criteria. The Class BWW1 use was assessed as "WINOFI" based on biological sampling data and continuous monitoring data. 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

CRWQ

23

WQ

CY 2022-2024

99990091

Lime Creek

Iowa DNR

6

WQ

CY 2022-2024

12100002

Lime Creek-Lime Creek Park- Brandon

Iowa DNR

6

BIO

See Below

154

Lime Creek

Lime Creek Park- Brandon


Presumptive Class A1 - Indicator Bacteria:

Site ID

Data Source ID

# Samples per Year (2022/ 2023/2024)

2022 Geometric Mean

2023 Geometric Mean

2024 Geometric Mean

Violates Annual Geometric Mean?

# 2022 SSM violations / SSM Violations needed for impairment

# 2023 SSM violations / SSM Violations needed for impairment

# 2024 SSM violations / SSM Violations needed for impairment

Violates Annual SSM Significantly >10% Rule?

Assessment Type

Support Level

99990091

23

5/5/5

332

279

827

YES

4 / NA

4 / NA

4 / NA

YES

EVALUATED

NOT

99990091

23

5/5/5

332

279

827

YES

0 / NA

0 / NA

1 / NA

NO

EVALUATED

NOT


Presumptive Class A1 - 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

12100002

6

35 / 3

7.3

8.2

7.7

0

7

NO

MONITORED

FULL

99990091

23

15 / 3

7.5

8.5

8.1

0

4

NO

MONITORED

FULL


Class BWW1 - Binomial 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

12100002

6

Chloride

9 / 3

21

25

23

NA

0 / 0

3

NO

EVALUATED

FULL

99990091

23

Chloride

15 / 3

21.8

46.7

28.2

NA

0 / 0

4

NO

MONITORED

FULL

12100002

6

Dissolved Oxygen

35 / 3

2.5

13

8

4

NA / NA

7

NO

MONITORED

FULL

99990091

23

Dissolved Oxygen

11 / 3

5.6

16.4

9.2

0

NA / NA

3

NO

MONITORED

FULL

12100002

6

pH

35 / 3

7.3

8.2

7.7

0

NA / NA

7

NO

MONITORED

FULL

99990091

23

pH

15 / 3

7.5

8.5

8.1

0

NA / NA

4

NO

MONITORED

FULL

12100002

6

Sulfate

9 / 3

12

88

25

0

NA / NA

3

NO

MONITORED

FULL

99990091

23

Sulfate

15 / 3

10.3

21.5

17

0

NA / NA

4

NO

MONITORED

FULL

12100002

6

Temperature

35 / 3

6.1

26.3

16.9

0

NA / NA

7

NO

MONITORED

FULL

99990091

23

Temperature

15 / 3

5.6

26.5

18

0

NA / NA

4

NO

MONITORED

FULL


Class BWW1 - Toxic Parameters:

Site ID

Data Source ID

Parameter Name

# Samples / # Years

Maximum Value

Mean Value

Median Value

# Acute / Chronic Violations

>1 Acute / Chronic Violation

Assessment Type

Support Level

12100002

6

Ammonia

20 / 3

1.5

0.1

0.02

0 / 0

NO

MONITORED

FULL


Class BWW1 - 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

154

10/7/24

32.5

47c

MS

Surber

59

Good

70

Fail

154

8/29/24

32.5

47c

MS

Surber

60

Good

70

Fail

154

7/31/24

32.5

47c

MS

Hess

58

Good

70

Fail

154

10/5/23

32.5

47c

MS

Surber

62

Good

70

Fail

154

8/24/23

32.5

47c

MS

Surber

78

Excellent

70

Pass

154

7/27/23

32.5

47c

MS

Hess

77

Excellent

70

Pass

154

9/12/22

32.5

47c

MS

Hess

68

Good

70

Fail

154

7/26/22

32.5

47c

MS

Hess

80

Excellent

70

Pass

154

7/19/21

32.5

47c

MS

Hess

80

Excellent

70

Pass

154

9/23/20

32.5

47c

MS

Hess

75

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

154

10/7/24

32.5

47c

MS

Yes

77

Excellent

65

Pass

154

8/24/23

32.5

47c

MS

Yes

84

Excellent

65

Pass

154

9/12/22

32.5

47c

MS

Yes

87

Excellent

65

Pass

154

7/19/21

32.5

47c

MS

Yes

81

Excellent

65

Pass

154

9/23/20

32.5

47c

MS

Yes

90

Excellent

65

Pass


Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Fail (5/10)

WINOFI

Fish

Monitored

Pass (5/5)

Full

Assessment was evaluated because the benthic

Overall

Evaluated

Fail

WINOFI

3bc

macroinvertebrate assessment was inconclusive.


Class BWW1- Continuous DO Monitoring:

Site ID

Data Source ID

# Days Monitoring (2022/2023)

DO Criteria Type

# 2022 Violations/Violations needed for impairment

# 2023 Violations/Violations needed for impairment

Violates Annual Significantly >10% Rule?

Assessment Type

Support Level

24 hr

2/25

31/20

Yes

12100002

6

191/16

16 hr

0/25

6/20

No

Monitored

WINOFI


Class HH - No Data

Monitoring and Methods
Assessment Key Dates
4/11/2022
Monitoring Start
7/26/2022
Biological Monitoring
7/19/2021
Biological Monitoring
10/7/2024
Biological Monitoring
8/29/2024
Biological Monitoring
9/23/2020
Biological Monitoring
9/12/2022
Biological Monitoring
10/7/2024
Monitoring End
7/31/2024
Biological Monitoring
10/5/2023
Biological Monitoring
8/24/2023
Biological Monitoring
7/27/2023
Biological Monitoring
Methods
200
Physical/Chemical Monitoring
315
Regional reference site approach
320
Benthic macroinvertebrate surveys
330
Fish surveys
420
Indicator bacteria monitoring
860
Other Agencies/Organizations provided monitoring data