Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Middle Fork Little Maquoketa River IA 01-TRK-138

Alternate name(s) for this segment: Bankston Creek

from west line of S31 T90N R1E (Dubuque Co.) to north line of S33 T90N R1W Dubuque Co.

Cycle
2024
Release Status
Final
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Unknown
Created
11/1/2023 8:12:30 AM
Updated
1/31/2024 2:35:43 PM
Use Support
Class A1
Recreation - Primary contact
Not Assessed
Class A2
Recreation - Secondary contact
Not Assessed
Class BCW1
Aquatic Life - Cold Water Type 1
Not Supported
Support Level
Not Supported
Impairment Code
5b-v - Biological - verified
Cause Magnitude
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2006
Impairment Rationale
Low Biotic Index
Data Source
Biological monitoring: Iowa DNR WQMA
TMDL Priority
Tier IV
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
2016
Impairment Rationale
Significantly > 10% of samples fail to meet criterion
Data Source
Special project/study: Iowa DNR
Class HH
Human Health -
Not Assessed
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The Class BCW1 use was assessed as "not supported" based on based on biological sampling data and "WINOFI" based on continuous temperature 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

Iowa DNR

6

BIO

See Below

419

Middle Fork Little Maquoketa River

Rickardsville – REMAP #261


Presumptive Class A1 - No Data


Class A2 - No Data


Class BCW1 - Biological Sampling:


Benthic Macroinvertebrates:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage/Thermal

BM Sample Gear

CBI score

CBI Class

CBI BIT

CBI Pass/Fail

419

8/31/16

13

52b

MS/CW

Hess

45

NA

60

Fail

419

7/18/16

13

52b

MS/CW

Hess

49

NA

60

Fail

419

9/4/12

13

52b

MS/CW

Hess

35

NA

60

Fail

419

7/23/12

13

52b

MS/CW

Hess

42

NA

60

Fail


Overall Assessment:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Fail (0/4)

Not

5bv

Assessment was evaluated because it included samples not collected in the last five years.


Class BCW1 - Trout Reproduction:


Based on the January 2024 trout reproduction in Iowa streams summary prepared by the DNR Fisheries Bureau, the Class BCW1 coldwater aquatic life use of Middle Fork Little Maquoketa River (a.k.a. Bankston Cr.) was assessed as "fully supported." According to the updated summary, this stream was placed in Category I: streams that exhibit consistent natural reproduction and maintain a wild population of one or more trout species without any stocking.


Class BCW1 – Continuous DO Monitoring: 2016

Site ID

Data Source ID

# Days Monitoring (2016)

DO Criteria Type

# 2016 violations / Violations needed for impairment

Violates Annual Significantly >10% Rule?

Assessment Type

Support Level

24 hr

4/12

No

419

6

72

16 hr

0/12

No

Evaluated

Full


Class BCW1 - Continuous Temperature Monitoring: 2012


The maximum stream temperature recorded during the sensor deployment period was 22.8 degrees (C). The BCW1 temperature criterion of 20 (C) was exceeded in 22 of 55 days. The percentage exceeding (40%) was greater than (failing) the 10% impairment threshold with high statistical confidence (>90%). Based on those data, the BCW1 aquatic life use was assessed as "WINOFI"due to temperature criterion violations. The assessment type is “evaluated” because it is based on data collected from a single year. In order to meet the requirements for a “monitored” assessment, the DNR’s continuous monitoring assessment methodology requires monitoring data from two or more years within the assessment period.


Class HH - No Data

Monitoring and Methods
Assessment Key Dates
7/23/2012
Biological Monitoring
7/10/2012
Monitoring Start
9/15/2012
Monitoring End
7/18/2016
Biological Monitoring
8/31/2016
Biological Monitoring
9/4/2012
Biological Monitoring
1/1/2024
Biological Monitoring
Methods
120
Surveys of fish and game biologists/other professionals
150
Monitoring data more than 5 years old
200
Physical/Chemical Monitoring
315
Regional reference site approach
320
Benthic macroinvertebrate surveys
330
Fish surveys