South Raccoon River IA 04-RAC-1183

from confluence with Middle Raccoon R. (S9 T78N R29W Dallas Co.) to confluence with Brushy Cr. in S22 T79N R31W Guthrie 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 2018 - 2020
Stream/River Water Quality Data	CY 2018 - 2020
Lake Water Quality Data	CY 2016 - 2020
Biological Sampling Data	CY 2016 - 2020*
Fish Kill Data	CY 2016 - 2020
Fish Tissue Sampling Data	CY 2016 - 2020
Continuous Dissolved Oxygen Sampling Data	CY 2016 - 2020
*Biological sites sampled in both 2015 and 2019 were also assessed.

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Cycle: 2022
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Unknown
Created: 12/10/2021 12:49:20 PM
Updated: 1/13/2022 1:08:13 PM

Use Support

Class A1

Recreation - Primary contact

WINOFI

Bacteria: Indicator Bacteria- E. coli

Support Level

Further Investigation Needed

Impairment Code

3b - Use potentially impaired based on an evaluated assessment.

Cause Magnitude

High

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2008

Impairment Rationale

Geometric mean criterion exceeded

Data Source

TMDL monitoring: Iowa DNR

Class BWW1

Aquatic Life - Warm Water Type 1

Not Supported

Fish Kill: Caused By Fertilizer Spill

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

Agriculture

Source Confidence

Moderate

Cycle Added

2016

Impairment Rationale

Pollutant-caused fish kill

Data Source

Fish kill investigation: Iowa DNR

TMDL Priority

Tier IV

Class HH

Human Health -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class A1 use was assessed as "WINOFI" due to levels of indicator bacteria that violated state water quality criteria. The Class BWW1 use was assessed as "not supported" due to a fish kill investigation. 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	181	South Raccoon River	Nations Bridge County Park - Stuart
Iowa DNR	6	BIO	See Below	1266	South Raccoon River	Redfield – REMAP #407
Iowa DNR	6	WQ	CY 2005	11250001	South Raccoon River	Site 32 at Redfield

Class A1 – Indicator Bacteria: 2005

Site ID	Data Source ID	# Samples / # Years	2005 Geometric Mean (4 samples)	Annual Geometric Mean Violation	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
11250001	6	4 / 1	6734	Yes	4	100%	NA	Evaluated	WINOFI

Class BWW1 - Biological Sampling:

Benthic Macroinvertebrates:

Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	BM Sample Gear	BMIBI score	BMIBI Class	47f BMIBI BIT	BMIBI Pass/ Fail
181	7/9/20	330.3	47f	MS	Hess	53	Fair	51	Pass
1266	7/16/20	374	47f	MS	Hess	65	Good	51	Pass
181	7/25/12	330.3	47f	MS	Hess	65	Good	51	Pass

Fish:

Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	Riffle Stream?	FIBI score	FIBI Class	47f FIBI BIT	FIBI Pass/ Fail
181	7/9/20	330.3	47f	MS	NA	54	Good	36	Pass
1266	7/16/20	374	47f	MS	NA	27	Fair	36	Fail
181	7/25/12	330.3	47f	MS	NA	53	Good	36	Pass

Overall:

Community	Assessment Type	Assessment Result	Support Level	IR Category	Reason
Benthic Macroinvertebrates	Evaluated	Pass (3/3)	Full
Fish	Evaluated	Pass (2/3)	Full	1	Assessment was evaluated because one of the samples used to complete
Overall	Evaluated	Pass	Full		the assessment was older than five years.

Class BWW1 – Fishkill Assessment:

The Class BWW1 aquatic life use assessment based on the 2014 fish kill placed this segment in Category 5b. The fish kill was caused by a “pollutant” or was suspected to be caused by a “pollutant”; therefore, the Class BWW1 use was considered impaired. Because the source of the pollutant was not identified and/or the enforcement actions taken against the responsible party have not been resolved, the Class BWW1 use was placed in Category 5b. Due to uncertainty regarding the recovery of the aquatic life following the fish kill, any existing fish kill 5b impairment will remain in Category 5b until more recent sampling has shown recovery of the aquatic community or the responsible party has paid restitution.

Details about the 2014 fish kill can be found here:https://programs.iowadnr.gov/fishkill/Events/874

Class HH – No Data

Monitoring and Methods

Assessment Key Dates

7/25/2012

Biological Monitoring

5/26/2005

Non-fixed Monitoring Start Date

6/23/2005

Non-fixed Monitoring End Date

4/11/2014

Fish Kill

7/16/2020

Biological Monitoring

7/9/2020

Biological Monitoring

Methods

120

Surveys of fish and game biologists/other professionals

140

Incidence of spills and/or fish kills

150

Monitoring data more than 5 years old

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

330

Fish surveys

380

Quantitative physical habitat assessment

420

Indicator bacteria monitoring