Turkey River IA 01-TRK-156

from confluence with N. Br. Turkey R. (S31 T99N R11W Howard Co.) to confluence with S. Br. Turkey R. in S2 T98N R12W Howard Co.

Assessment Cycle

2024

Release Status

Pending

Data Collection Period

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.

Overall IR Category: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Unknown

Created: 11/1/2023 8:12:46 AM
Updated: 12/18/2023 11:21:32 AM

Assessment conducted in accordance with Iowa's 2024 IR methodology.

Use Support

Class A1

Recreation

Primary contact

Presumptive Use

Not Supported

Impairments

Support Level

Not Supported

Impairment Code

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

Cause Magnitude

Slight

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 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” due to 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 and water quality monitoring 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 2012-2014	15450015	Turkey River @ V46	TR90
Iowa DNR	6	BIO	See Below	1022	Turkey River	US confluence with North Fork Turkey – TK008

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
15450015	6	23 / 3	284	606	163	Yes	14	61%	Yes	Evaluated	Not

Presumptive Class A1 - pH:

Site ID	Data Source ID	# Samples / # Years	Maximum Value	Mean Value	Median Value	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
15450015	6	24/ 3	8.7	8	8	0	0%	No	Evaluated	Full

Class BWW2 - Binomial Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Maximum Value	Mean Value	Median Value	# Acute / Chronic Violations	% Acute/ Chronic Violations	Significantly >10% Violations	Assessment Type	Support Level
15450014	6	Ammonia	16 / 2	0.44	0.09	0.05	0 / 0	0% / 0%	No	Evaluated	Full
15450014	6	Chloride	17 / 3	41	31.9	33	0 / 0	0% / 0%	No	Evaluated	Full
15450014	6	Dissolved oxygen	24 / 3	11	7	7.5	NA / 2	NA / 8%	No	Evaluated	Full
15450014	6	pH	24 / 3	8.7	8	8	0 / NA	0% / NA	No	Evaluated	Full
15450014	6	Temperature	24 / 3	28	14.7	14.5	0 / 0	0% / 0%	No	Evaluated	Full

Class BWW2 - Biological Sampling:

Fish:

Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	Riffle Stream?	FIBI score	FIBI Class	47c FIBI BIT	FIBI Pass/ Fail
1022	8/21/19	28	47c	MS	Undetermined	65	Good	44	Pass
1022	7/31/18	28	47c	MS	Undetermined	63	Good	44	Pass
1022	8/7/17	28	47c	MS	Undetermined	64	Good	44	Pass
1022	8/16/16	28	47c	MS	Undetermined	71	Excellent	44	Pass

Overall:

Community	Assessment Type	Assessment Result	Support Level	IR Category	Reason
Fish	Monitored	Pass (4/4)	Full		Assessment was monitored because the assessment used multiple
Overall	Monitored	Pass	Full	1	samples collected in the last five years.

Monitoring and Methods

Assessment Key Dates

4/4/2012

Monitoring Start

11/5/2014

Monitoring End

8/21/2019

Biological Monitoring

8/16/2016

Biological Monitoring

8/7/2017

Biological Monitoring

7/31/2018

Biological Monitoring

Methods

150

Monitoring data more than 5 years old

200

Physical/Chemical Monitoring

315

Regional reference site approach

330

Fish surveys

420

Indicator bacteria monitoring