Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Boylan Creek IA 02-WFC-1870

confluence with unnamed tributary (T93N R18W Sec31 Butler Co.) to headwaters (T94N R19W Sec30 Cerro Gordo 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 8:13:27 AM
Updated
2/1/2024 1:46:30 PM
Use Support
Class A1
Recreation - Primary contact
Not Assessed
Class BWW1
Aquatic Life - Warm Water Type 1
WINOFI
Impairment Code
3b-u - Use potentially biologically impaired based on uncalibrated IBI metrics.
Cause Magnitude
Slight
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2020
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 BWW1 use was assessed as “WINOFI” based on biological sampling 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

Iowa DNR

6

BIO

See Below

333

Boylan Creek

Aredale – REMAP #5

Iowa DNR

6

WQ

2017

333

Boylan Creek

Aredale – REMAP #5

Iowa DNR

6

BIO

See Below

899

Boylan Creek

Aredale

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

47c BMIBI BIT

BMIBI Pass/Fail

899

8/11/14

13.5

47c

MS/WW

ArtSub

67

Good

52

Pass


Fish:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage/Thermal

Riffle Stream?

FIBI score

FIBI Class

47c FIBI BIT

FIBI Pass/Fail

333

7/26/17

18.4

47c

MS/WW

No

32

Fair

44

Fail

899

8/11/14

13.5

47c

MS/WW

No

49

Fair

44

Pass


Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Pass (1/1)

Full

Fish

Evaluated

Fail (1/2)

WINOFI

Assessment was evaluated because the drainage areas of

Overall

Evaluated

Fail

WINOFI

3bu

the sample sites were smaller than the calibrated range.


Presumptive Class BWW1- Continuous DO Monitoring:

Site ID

Data Source ID

# Days Monitoring (2017)

DO Criteria Type

# 2017 violations / Violations needed for impairment

Violates Annual Significantly >10% Rule?

Assessment Type

Support Level

24 hr

0/5

No

333

6

19

16 hr

0/5

No

Evaluated

Full

Monitoring and Methods
Assessment Key Dates
8/11/2014
Biological Monitoring
7/26/2017
Biological Monitoring
7/7/2017
Monitoring Start
7/26/2017
Monitoring End
Methods
150
Monitoring data more than 5 years old
200
Physical/Chemical Monitoring
315
Regional reference site approach
320
Benthic macroinvertebrate surveys
330
Fish surveys