Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Beaver Creek IA 02-WIN-1837

from confluence with DD54 in T98N R23W S25 Winnebago Co. to outlet structure at Rice Lake T99N R22W S19 Worth Co.

Cycle
2020
Release Status
Final
Overall IR
3 - Insufficient data exist to determine whether any designated uses are met.
Trend
Unknown
Created
9/23/2020 9:09:34 AM
Updated
10/19/2020 12:13:33 PM
Use Support
Class A1
Recreation - Primary contact
Not Assessed
Class BWW1
Aquatic Life - Warm Water Type 1
WINOFI
Impairment Code
3b - Use potentially impaired based on an evaluated assessment.
Cause Magnitude
Moderate
Status
Delisted
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2010
Impairment Rationale
Violations of acute criterion
Cycle Delisted
2020
Delisting Rationale
Assessment Error
Data Source
N/A
Impairment Code
3b-u - Use potentially biologically impaired based on uncalibrated IBI metrics.
Cause Magnitude
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2010
Impairment Rationale
Low Biotic Index
Data Source
Biological monitoring: Iowa DNR WQMA
General Use
General Use water -
Not Assessed
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The presumptive Class BWW1 use was assessed as “partially supported” based on biological sampling data and continuous monitoring data. The previous 5a impairment based on the 2003 continuous monitoring data was de-listed due to assessment error (see below for explanation). All other designated uses were "not assessed".  

Assessment Explanation

Sources of Data:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

Iowa DNR

6

BIO

See Below

358

Beaver Creek

Lake Mills – REMAP #84

Iowa DNR

6

BIO

See Below

626

Beaver Creek

230 Ave


Presumptive Class A1 - No Data


Presumptive Class BWW1 - 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

358

7/22/03

13

47b

MS/WW

ArtSub

36

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

626

7/24/06

35

47b

MS/WW

No

31

Fair

32

Fail

358

7/22/03

13

47b

MS/WW

No

28

Fair

32

Fail

Overall:

Community

Assessment Type

Assessment Result

Support Level

Earned IR Category

Actual IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Fail (0/1)

Partial

Fish

Evaluated

Fail (0/2)

Partial

Overall

Evaluated

Fail

Partial

3bu

3bu

Assessment is evaluated because the drainage areas of the sites were smaller than the calibrated range.


Presumptive Class BWW1 – Continuous Monitoring Data:

In July 2003, a dissolved oxygen and temperature data logger was deployed in the stream for 13 days. The data logger recorded an early morning

dissolved oxygen level below 2 mg/L, which is less than the instantaneous criterion of 4 mg/L for Class BWW1 streams. This evidence

of presumptive Class BWW1 impairment is considered "evaluated" rather than "monitored" because the data were obtained from a single, short-term

monitoring event. The previous Category 5a impairment based on these data was due to assessment error. Based on DNR IR methodology, continuous

monitoring data must be collected for a minimum of two weeks in two separate years to be considered for Category 5a impairment. See Attachment 6

of Iowa'sMethodology for Iowa’s 2020 Water Quality Assessment,Listing, and Reporting Pursuant toSections 305(b) and 303(d) of the Federal Clean

Water Act for further information.

Monitoring and Methods
Assessment Key Dates
7/24/2006
Biological Monitoring
7/22/2003
Biological Monitoring
7/1/2003
Non-fixed Monitoring Start Date
7/14/2003
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