French Creek IA 01-UIA-248

from mouth (T99N R5W S1 Allamakee County) to confluence with French Creek - West Branch (T99N R23W S23 Allamakee County)

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 2016 - 2018
Stream/River Water Quality Data	CY 2016 - 2018
Lake Water Quality Data	CY 2014 - 2018
Biological Sampling Data	CY 2014 - 2018*
Fish Kill Data	CY 2014 - 2018
Fish Tissue Sampling Data	CY 2014 - 2018
Continuous Dissolved Oxygen Sampling Data	CY 2014 - 2018
*Biological sites sampled in both 2013 and 2017 were also assessed.

Open Segment Map
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Cycle: 2020
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Unknown
Created: 8/24/2020 10:13:52 AM
Updated: 10/15/2020 10:36:56 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

High

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2008

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Watershed project monitoring

TMDL Priority

Tier III

Class A2

Presumptive Use

Recreation - Secondary 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

N/A

Cycle Added

2012

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Watershed project monitoring

TMDL Priority

Tier III

Class BCW1

Aquatic Life - Cold Water Type 1

Fully Supported

Class HH

Human Health -

Fully Supported

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The presumptive Class A1 and the presumptive Class A2 uses both remain assessed as "not supported" based on levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BCW1 use was assessed as "fully supported" based on biological sampling data and on the trout reproduction in Iowa streams summary prepared by the DNR Fisheries Bureau. The Class HH use remains assessed as "fully supported" based on fish tissue sampling data.

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	48	French Creek	French Creek SWMA - Waukon
Iowa DNR	6	BIO	See Below	539	French Creek (Main Branch)	Waukon
NEIARCD	19	WQ	CY 2012-2014	190050007	French Creek	Site 29
Iowa DNR	6	FT	See Below	154	French Creek	N of Churchtown

Presumptive Class A1 - Indicator Bacteria:

Site ID	Data Source ID	# Samples / # Years	2012 Geometric Mean	2013 Geometric Mean	2014 Geometric Mean	Annual Geometric Mean Violation	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
190050007	19	21 / 3	903	2442	622	Yes	18	86%	Yes	Evaluated	Not

Presumptive Class A2 - Indicator Bacteria:

Site ID	Data Source ID	# Samples / # Years	2012 Geometric Mean	2013 Geometric Mean	2014 Geometric Mean	Annual Geometric Mean Violation	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
190050007	19	21 / 3	903	2442	622	Yes	4	19%	No	Evaluated	Not

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
48	7/24/18	10	52b	MS/CW	Hess	70	NA	60	Pass
48	7/18/17	10	52b	MS/CW	Hess	71	NA	60	Pass
539	7/18/17	6	52b	MS/CW	Hess	76	NA	60	Pass
48	8/8/16	10	52b	MS/CW	Hess	73	NA	60	Pass

Overall Assessment:

Community	Assessment Type	Assessment Result	Support Level	Earned IR Category	Actual IR Category	Reason
Benthic Macroinvertebrates	Monitored	Pass (4/4)	Full	1	1	Assessment is monitored because the assessment used two or more samples collected in the last five years.

Class BCW1 – Trout Natural Reproduction:

Based on the January 2020 trout reproduction in Iowa streams summary prepared by the DNR Fisheries Bureau, the Class BCW1 coldwater aquatic life use of French Creek 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 HH – Fish Tissue Sampling:

Site ID	Date	Species Name	Biopart	# in sample	Hg result	Hg violation (>0.3)?	Assessment Type	Support Level
154	10/12/2015	brown trout	plug	5	0.050	No	Monitored	Full

Monitoring and Methods

Assessment Key Dates

1/1/2020

Biological Monitoring

4/3/2012

Fixed Monitoring Start Date

10/7/2014

Fixed Monitoring End Date

7/18/2017

Biological Monitoring

8/8/2016

Biological Monitoring

10/12/2015

Fish Tissue Monitoring

7/24/2018

Biological Monitoring

Methods

120

Surveys of fish and game biologists/other professionals

260

Fish tissue analysis

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

330

Fish surveys

420

Indicator bacteria monitoring