Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Badger Lake IA 04-UDM-1291

Webster County S19T90NR28W 4.5 mi N of Fort Dodge.

Cycle
2022
Release Status
Final
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trophic
Eutrophic
Trend
Stable
Created
12/30/2021 10:28:17 AM
Updated
1/28/2022 7:26:01 AM
Use Support
Class A1
Recreation - Primary contact
Not Supported
Support Level
Not Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
Slight
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2020
Impairment Rationale
Narrative criteria violation: aesthetically objectionable conditions
Data Source
Ambient monitoring: Iowa DNR-lakes
TMDL Priority
Tier I
Class BLW
Aquatic Life - Lakes and wetlands
WINOFI
Impairment Code
3b - Use potentially impaired based on an evaluated assessment.
Cause Magnitude
Moderate
Status
Continuing
Source
Agriculture
Source Confidence
Moderate
Cycle Added
2002
Impairment Rationale
Adverse impacts on plant/animal communities
Data Source
Biological monitoring: Iowa DNR Fisheries
Impairment Code
3b - Use potentially impaired based on an evaluated assessment.
Cause Magnitude
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2002
Impairment Rationale
Adverse impacts on plant/animal communities
Data Source
Biological monitoring: Iowa DNR Fisheries
Class HH
Human Health -
Not Assessed
Impairment Delistings
Cycle Added Class Cause Data Source Rationale
2018 Class A1 Algal Growth: Chlorophyll a Ambient monitoring: Iowa DNR-lakes New data: WQ improvement (chemical / physical / bacterial)
Documentation
Assessment Summary

The Class A1 use was assessed (monitored) as "not supported" due to aesthetically objectionable conditions caused by non-algal turbidity. The Class BLW use was assessed (evaluated) as “WINOFI” due to siltation and water quality impacts of common carp. 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

Iowa DNR

6

WQ

CY 2016-2020

22940001

Badger Lake


Class A1 - Indicator Bacteria: No Data


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

22940001

6

15 / 5

7.3

8.6

8.1

0

4

NO

Monitored

Full


Class A1 - Lake TSI's:

Site ID

Data Source ID

Parameter Name

# Samples / # Years

Minimum Value

Maximum Value

Median Value

Median TSI Violation?

Assessment Type

Support Level

22940001

6

Chlorophyll a TSI

15 / 5

26

84

56

NO

Monitored

Full

22940001

6

Secchi TSI

15 / 5

53

77

65

YES

Monitored

Not

22940001

6

Total Phosphorus TSI

15 / 5

35

88

71

NA

NA

NA

22940001

6

Inorganic suspended solids

15 / 5

0.6

16

4

NA

NA

NA

DNR's assessment methodology indicates that at least two assessment/listing cycles with a TSI value less than or equal to 63 are necessary to suggest de-listing of an impairment. The chlorophyll a TSI value for the 2018 assessment listing cycle was 64, which based on DNR's assessment/listing methodology indicated an impairment based on the narrative criteria protecting against aesthetically objectionable conditions. Because the TSI value for the 2020 assessment/listing cycle was less than the trigger of 65 (2020 listing for chlorophyll a was 56), and because the TSI value for the current listing cycle is 56, based on DNR's methodology, these values suggest "full support" of the Class A1 use protecting against aesthetically objectionable conditions and the impairment (5a) for chlorophyll a is suggested for delisting for the 2022 assessment/listing cycle.


Class BLW - 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

22940001

6

Ammonia

15 / 5

0.0003

0.209

0.06

NA

0 / 0

4

NO

Monitored

Full

22940001

6

Dissolved Oxygen

14 / 5

5.4

26.1

11.6

0

NA / NA

4

NO

Monitored

Full

22940001

6

pH

15 / 5

7.3

8.6

8.1

0

NA / NA

4

NO

Monitored

Full

22940001

6

Temperature

15 / 5

10.8

28.7

20.9

0

NA / NA

4

NO

Monitored

Full


Class BLW - Lake Planktonic Cyanobacteria:

Site ID

Data Source ID

# Samples

Maximum Cyanobacteria Wet Mass

Maximum Cyanobacteria % Composition

Median Cyanobacteria Wet Mass

Median Cyanobacteria % Composition

Median Cyanobacteria Concentration = 75th Percentile

Assessment Type

Support Level

22940001

6

4

0.00

0.0%

0.00

0.0%

NO

Evaluated

NA


Class HH -No Data


Additional information:

The Class BLW use was assessed (evaluated) as “WINOFI” based on information from the DNR Fisheries Bureau. Information from the DNR Fisheries Bureau suggests that siltation and the impacts of common carp on turbidity at this lake impair the aquatic life use.

Monitoring and Methods
Assessment Key Dates
5/16/2016
Non-fixed Monitoring Start Date
8/18/2020
Non-fixed Monitoring End Date
Methods
120
Surveys of fish and game biologists/other professionals
222
Non-fixed-station monitoring (conventional during key seasons and flows)
340
Primary producer surveys (phytoplankton/periphyton/macrophyton)