2024 assessment for Duck Creek

Duck Creek IA 01-UIA-254

mouth (NE 1/4 S14 T100N R6W Allamakee Co.) to IA/MN state line (S11 T100N R6W Allamakee Co.).

2024
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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Overall IR

5 - Water is impaired or threatened and a TMDL is needed.

Trend

Unknown

Created

11/1/2023 8:13:44 AM by

Updated

1/8/2024 2:59:03 PM by

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

Slight

303(d) Listing Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2014

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Watershed project monitoring

TMDL Priority

Tier III

Class BWW1

Presumptive Use

Aquatic Life - Warm Water Type 1

Fully Supported

303(d) Delistings for this Cycle

No delistings for this assessment cycle.

Documentation

Assessment Summary

The presumptive Class A1 use was assessed as “not supported” due to violations of Iowa water quality criteria for indicator bacteria (E. coli). The presumptive Class BWW1 use was assessed as "fully supported" based on the trout reproduction in Iowa streams summary prepared by the DNR Fisheries Bureau and on water quality monitoring data. Although not designated for coldwater aquatic life uses in the Iowa Water Quality Standards/Surface Water Classification, this stream is considered a trout stream by the DNR Fisheries Bureau and is identified as an "Outstanding Iowa Water" as part of Iowa's anti-degradation program. Thus, this stream segment is assessed as a coldwater stream for the Iowa’s Integrated Reporting cycle.

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY 2010-2011	13030001	Duck Creek at Waterloo Creek Dr (Site Duck 1)

Presumptive Class A1 - Indicator Bacteria: Historical

Site ID	Data Source ID	# Samples / # Years	2010 Geometric Mean	2011 Geometric Mean	Annual Geometric Mean Violation	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
13030001	6	30 / 2	530	90	Yes	16	53%	Yes	Evaluated	Not

Presumptive Class BWW1 - Binomial Parameters: Historical

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Minimum Value	# Acute / Chronic Violations	% Acute/ Chronic Violations	Significantly >10% Violations	Assessment Type	Support Level
13030001	6	Dissolved oxygen	11 / 1	7.0	NA / 0	NA / 0%	No	Evaluated	Full
13030001	6	Temperature	11 / 1	NA	0 / 0	0% / 0%	No	Evaluated	Full

Presumptive Class BWW1– Trout Natural Reproduction:

Even though Duck Creek is classified as a BWW1 stream, based on the January 2024 trout reproduction in Iowa streams summary prepared by the DNR Fisheries Bureau, the Class BWW1 coldwater aquatic life use of Duck Creek was assessed as "fully supported." According to the updated summary, this stream has reaches that are both Category I: streams that exhibit consistent natural reproduction and maintain a wild population of one or more trout species without any stocking and Category II: streams that exhibit recent but inconsistent reproductive success and occasional stocking may be needed to maintain the trout population(s).

Monitoring and Methods

Assessment Key Dates

4/20/2010

Monitoring Start

11/1/2011

Monitoring End

1/1/2024

Biological Monitoring

Methods

120

Surveys of fish and game biologists/other professionals

200

Physical/Chemical Monitoring

330

Fish surveys

420

Indicator bacteria monitoring