Upper Iowa River IA 01-UIA-239

from confluence with Trout Cr. (S9 T98N R7W Winneshiek Co.) to confluence with Tenmile Cr. in S1 T98N R9W Winneshiek 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
View assessment methodology in new window

Cycle: 2024
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Unknown
Created: 11/1/2023 8:12:24 AM
Updated: 1/16/2024 8:53:32 AM

Use Support

Class A1

Recreation - Primary contact

Not Supported

Bacteria: Indicator Bacteria- E. coli

Support Level

Not Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2006

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Watershed project monitoring

TMDL Priority

Tier III

Class BWW1

Aquatic Life - Warm Water Type 1

Not Supported

Biological: loss of native mussel species

Support Level

Not Supported

Impairment Code

5b - Biological impairment or pollutant-caused fish kill - unknown source. No administrative action.

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2004

Impairment Rationale

Loss of >50% of native mussel species

Data Source

Special project/study

TMDL Priority

Tier IV

Class HH

Human Health -

Not Supported

Fish Consumption Advisory: Mercury

Support Level

Not Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2006

Impairment Rationale

Fish consumption advisory in effect: no more than 1 meal/week

Data Source

Fish contaminant monitoring: Iowa DNR

TMDL Priority

Tier IV

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class A1 use remains assessed as “not supported” due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BWW1 use remains assessed as "not supported" based on results of a 1998-99 statewide assessment of freshwater mussels in Iowa streams and on the results of a 2012 mussel survey. The Class HH use was assessed as “not supported” based on the continuance of a historic fish consumption advisory for this segment of the Upper Iowa River.

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
NEIARCD	19	WQ	CY 2012-2014	191910010	Upper Iowa River Freeport	Site 17

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
191910010	19	20 / 3	60	463	616	Yes	9	45%	Yes	Evaluated	Not

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
191910010	19	14 / 2	8.52	8.31	8.31	0	0%	No	Evaluated	Full

Class BWW1 - 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
191910010	19	pH	14 / 2	8.52	8.31	8.31	0 / NA	0% / NA	No	Evaluated	Full
191910010	19	Temperature	14 / 2	20.5	14.66	16.35	0 / 0	0% / 0%	No	Evaluated	Full

Class BWW1 – Freshwater Mussel Sampling:

Freshwater Mussel Survey	# Freshwater Mussel Species	# Freshwater Mussel Species Increase/Decrease	% Freshwater Mussel Species Increase/Decrease	Assessment Type	Support Level	IR Category
1984-85 (Frest 1987)	6
1998-99 (Arbuckle et al. 2000)	0	-6	-100%	Evaluated	Not	5b
2012 (Iowa DNR WIS)	1
As presented by Arbuckle et al. (2000), the potential causes of declines in species richness of Iowa's freshwater mussels include siltation, destabilization of stream substrate, stream flow instability, and high instream levels of nutrients (phosphorus and nitrogen). Their study also suggested the importance of stream shading provided by riparian vegetation to mussel species richness.

Class HH - Fish Tissue Sampling:

Support Level

Not

A historic one meal/week mercury consumption advisory for any fish exists on this segment. Based on IR Methodology, the Class HH (fish consumption) use was assessed as “not supported.”

Monitoring and Methods

Assessment Key Dates

9/30/1999

Biological Monitoring

7/25/2006

Biological Monitoring

8/6/2012

Biological Monitoring

4/9/2012

Monitoring Start

10/7/2014

Monitoring End

Methods

150

Monitoring data more than 5 years old

200

Physical/Chemical Monitoring

260

Fish tissue analysis

320

Benthic macroinvertebrate surveys

420

Indicator bacteria monitoring