South Fork Catfish Creek IA 01-TRK-130

mouth (S2 T88N R2E Dubuque Co.) to confluence with unnamed tributary in SW 1/4 S3 T88N R1E Dubuque Co.

Open Data Collection Period Modal

For purposes of developing stream/river water quality assessments for integrated reporting, three years of water quality data are typically used for both conventional pollutant parameters (e.g., indicator bacteria) and the less frequently monitored toxic parameters (e.g., toxic metals). Since the 2004 IR cycle, DNR has used a three-year data gathering period for streams, rivers, and beaches. For most assessments, the use of three years of data increases the number of samples upon which the decision on use support is based and helps address the problem of weather-related year-to-year fluctuations in water quality.

Due to the lower sampling frequency in Iowa’s ambient lake, biological, fish kill, and fish tissue monitoring programs, five years of data are used for developing IR assessments and for identifying Section 303(d) listings.

Data Type	Data Timeframe
Beach Sampling Data	CY 2020 - 2022
Stream/River Water Quality Data	CY 2020 - 2022
Lake Water Quality Data	CY 2018 - 2022
Biological Sampling Data	CY 2018 - 2022*
Fish Kill Data	CY 2018 - 2022
Fish Tissue Sampling Data	CY 2018 - 2022
Continuous Dissolved Oxygen Sampling Data	CY 2018 - 2022
*Biological sites sampled in both 2017 and 2021 were also assessed.

Open Segment Map
View assessment methodology in new window

Cycle: 2024
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Unknown
Created: 11/1/2023 8:12:46 AM
Updated: 1/16/2024 9:08:50 AM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Not Supported

Bacteria: Indicator Bacteria- E. coli

Support Level

Not Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

High

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2012

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Watershed project monitoring

TMDL Priority

Tier III

Class A3

Recreation - Children's contact

Not Supported

Bacteria: Indicator Bacteria- E. coli

Support Level

Not Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

High

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2020

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Watershed project monitoring

TMDL Priority

Tier III

Class BWW2

Aquatic Life - Warm Water Type 2

Fully Supported

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The presumptive Class A1 and the Class A3 uses remain assessed as "not supported” due to levels of indicator bacteria (E. coli) that violated the Iowa water quality criteria. The Class BWW2 use was assessed as "fully supported" based on biological sampling data and continuous DO monitoring.

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	297	South Fork Catfish Creek	Dubuque – REMAP #49
Catfish Creek Watershed Project	18	WQ	CY 2010	WQ-8	South Fork Catfish Creek near North Cascade Rd	WQ-8
Catfish Creek Watershed Project	18	WQ	CY 2010	WQ-10	South Fork Catfish Creek near English Mill Rd	WQ-10
Catfish Creek Watershed Project	18	WQ	CY 2010	WQ-14	South Fork Catfish Creek near Cousins Rd	WQ-14

Presumptive Class A1/Class A3 – Indicator Bacteria: 2010

Site ID	Data Source ID	# Samples / # Years	2010 Geometric Mean	Annual Geometric Mean Violation	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
WQ-8	18	11 / 1	3983	Yes	11	100%	Yes	Evaluated	Not
WQ-10	18	11 / 1	2860	Yes	11	100%	Yes	Evaluated	Not
WQ-14	18	11 / 1	4369	Yes	11	100%	Yes	Evaluated	Not

Class BWW2 - Biological Sampling:

Benthic Macroinvertebrates:

Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	BM Sample Gear	BMIBI score	BMIBI Class	52b BMIBI BIT	BMIBI Pass/Fail
297	8/13/19	8.0	52b	MS	Hess	80	Excellent	61	Pass

Fish:

Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	Riffle Stream?	FIBI score	FIBI Class	52b FIBI BIT	FIBI Pass/Fail
297	8/13/19	8.0	52b	MS	NA	60	Good	52	Pass

Overall:

Community	Assessment Type	Assessment Result	Support Level	IR Category	Reason
Benthic Macroinvertebrates	Evaluated	Pass (1/1)	Full
Fish	Evaluated	Pass (1/1)	Full		Assessment was evaluated because
Overall	Evaluated	Pass	Full	1	it was based on a single sample.

Class BWW2 – Continuous DO Monitoring:

Site ID	Data Source ID	# Days Monitoring (2019)	DO Criteria Type	# 2019 violations / Violations needed for impairment	Violates Annual Significantly >10% Rule?	Assessment Type	Support Level
			24 hr	0/4	No
297	6	15	16 hr	0/4	No	Evaluated	Full

Monitoring and Methods

Assessment Key Dates

5/10/2010

Monitoring Start

10/27/2010

Monitoring End

8/14/2019

Biological Monitoring

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

420

Indicator bacteria monitoring