North Cedar Creek IA 01-YEL-431

mouth (S8 T94N R3W Clayton Co.) to west line of S24 T94N R4W Clayton 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.

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Cycle: 2024
Release Status: Final
Overall IR: 2 - Some of the designated uses are met but there is insufficient data to determine if remaining designated uses are met.
Trend: Unknown
Created: 11/1/2023 8:12:40 AM
Updated: 1/12/2024 2:36:29 PM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Not Assessed

Class A2

Recreation - Secondary contact

Not Assessed

Class BCW1

Aquatic Life - Cold Water Type 1

Fully Supported

Class HH

Human Health -

Fully Supported

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

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 (fish consumption) use was assessed as "fully supported" based on fish tissue sampling 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	10	North Cedar Creek	Public Access Area – Sny Magill
Iowa DNR	6	BIO	See Below	474	North Cedar Creek	Clayton – REMAP #159
Iowa DNR	6	FT	See Below	1367	North Cedar Creek	North Cedar WMA

Presumptive Class A1 – No Data

Class A2 – No Data

Class BCW1 - Biological Sampling:

Benthic Macroinvertebrates:

Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	BM Sample Gear	CBI score	CBI Class	CBI BIT	CBI Pass/Fail
10	8/1/22	5.1	52b	MS	Hess	59	NA	60	Fail
10	7/29/21	5.1	52b	MS	Hess	70	NA	60	Pass
10	8/17/20	5.1	52b	MS	Hess	66	NA	60	Pass
10	7/17/19	5.1	52b	MS	Hess	68	NA	60	Pass
474	7/17/19	4.2	52b	MS	Surber	67	NA	60	Pass
10	7/24/18	5.1	52b	MS	Hess	63	NA	60	Pass

Overall:

Community	Assessment Type	Assessment Result	Support Level	IR Category	Reason
Benthic Macroinvertebrates	Monitored	Pass (5/6)	Full	1	Assessment was monitored because it included multiple samples collected in the previous five years.

Class BCW1 - Trout Natural Reproduction:

Based on the January 2023 trout reproduction in Iowa streams summary prepared by the DNR Fisheries Bureau, the Class BCW1 coldwater aquatic life use of North Cedar 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	Biopart	Year	Species	# in sample / # of samples	Avg Length (cm)	(Avg) Hg (ppm)
1367	tissue plug	2019	brook trout	10	25.7	0.032
Support Level	Full

Monitoring and Methods

Assessment Key Dates

7/29/2021

Biological Monitoring

1/1/2023

Biological Monitoring

8/17/2020

Biological Monitoring

7/17/2019

Biological Monitoring

7/24/2018

Biological Monitoring

7/1/2019

Fish Tissue Monitoring

8/1/2022

Biological Monitoring

Methods

260

Fish tissue analysis

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

330

Fish surveys