Coffins Creek IA 01-MAQ-51

mouth (S19 T89N R5W Delaware Co.) to unnamed tributary in S29 T89N R6W Delaware 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
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Cycle: 2024
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Stable
Created: 11/1/2023 8:12:46 AM
Updated: 12/12/2023 9:07:36 AM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Not Supported

Bacteria: Indicator Bacteria- E. coli

Support Level

Not Supported

Impairment Code

5p - Impairment occurs on a waterbody with a presumptive A1 or B(WW1) use.

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2010

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Special project/study

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 use remains assessed as "not supported" based on levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BWW2 use was assessed as “fully supported" based on biological sampling data.

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY 2012-13	15280024	Coffins Creek	Coffins Grove Park
Iowa DNR	6	BIO	See Below	1027	Coffins Creek	CO002 – Maquoketa tributary below 145th Ave
Iowa DNR	6	BIO	See Below	1028	Coffins Creek	CO003 – NE of Masonville

Presumptive Class A1 - Indicator Bacteria: Historical

Site ID	Data Source ID	# Samples / # Years	2012 Geometric Mean	2013 Geometric Mean	Annual Geometric Mean Violation	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
15280024	6	14 / 2	752	342	Yes	12	86%	Yes	Evaluated	Not

Class BWW2 - Biological Sampling:

Fish:

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	Riffle Stream?	FIBI score	FIBI Class	47c FIBI BIT	FIBI Pass/Fail
1028	8/16/22	40	47c	MS	Undetermined	87	Excellent	44/65	Pass
1027	7/29/22	49	47c	MS	Undetermined	84	Excellent	44/65	Pass
1028	7/29/21	40	47c	MS	Undetermined	94	Excellent	44/65	Pass
1027	7/28/21	49	47c	MS	Undetermined	76	Excellent	44/65	Pass
1028	7/23/20	40	47c	MS	Undetermined	87	Excellent	44/65	Pass
1027	7/22/20	49	47c	MS	Undetermined	77	Excellent	44/65	Pass
1028	7/24/19	40	47c	MS	Undetermined	87	Excellent	44/65	Pass
1027	7/23/19	49	47c	MS	Undetermined	76	Excellent	44/65	Pass
1028	7/17/18	40	47c	MS	Undetermined	82	Excellent	44/65	Pass
1027	7/16/18	49	47c	MS	Undetermined	71	Excellent	44/65	Pass

Overall:

Community	Assessment Type	Assessment Result	Support Level	IR Category	Reason
Fish	Monitored	Pass (10/10)	Full		Assessment was monitored because multiple samples collected in the
Overall	Monitored	Pass	Full	1	last five years were used to complete the assessment.

Monitoring and Methods

Assessment Key Dates

5/7/2012

Monitoring Start

11/18/2013

Monitoring End

8/16/2022

Biological Monitoring

7/23/2020

Biological Monitoring

7/22/2020

Biological Monitoring

7/29/2022

Biological Monitoring

7/29/2019

Biological Monitoring

7/26/2019

Biological Monitoring

7/28/2021

Biological Monitoring

7/17/2018

Biological Monitoring

7/29/2021

Biological Monitoring

Methods

150

Monitoring data more than 5 years old

315

Regional reference site approach

330

Fish surveys

420

Indicator bacteria monitoring