Elk Run IA 04-RAC-1161

mouth-> DD-72/81 S5T85NR34W Carroll 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: 3 - Insufficient data exist to determine whether any designated uses are met.
Trend: Unknown
Created: 11/1/2023 8:13:07 AM
Updated: 1/24/2024 11:01:38 AM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Not Assessed

Class BWW2

Aquatic Life - Warm Water Type 2

WINOFI

Biological: low fish & invert IBIs- cause unknown

Support Level

Further Investigation Needed

Impairment Code

3b-c - Use potentially biologically impaired based on calibrated IBI metrics.

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2014

Impairment Rationale

Low Biotic Index

Data Source

Biological monitoring: Iowa DNR WQMA

Impairment Delistings

Cycle Added	Class	Cause	Data Source	Rationale
2010	Class BWW2	Fish Kill: Caused By Animal Waste	Biological monitoring: Iowa DNR fish kill follow-up	New data: recovery of fish community from pollutant-caused fish kill

Documentation

Assessment Summary

The Class BWW2 use was assessed as "WINOFI" based on a failed single fish and benthic macroinvertebrate sample. 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	860	Elk Run Creek	Lanesboro

Presumptive Class A1 – No Data

Class BWW2 - Biological Sampling:

Benthic Macroinvertebrates:

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	BM Sample Gear	BMIBI score	BMIBI Class	47b BMIBI BIT	BMIBI Pass/Fail
860	8/4/11	33	47b	MS	Hess	44	Fair	62	Fail

Fish:

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	Riffle Stream?	FIBI score	FIBI Class	47b FIBI BIT	FIBI Pass/Fail
860	8/4/11	33	47b	MS	Yes	45	Fair	53	Fail

Overall:

Community	Assessment Type	Assessment Result	Support Level	IR Category	Reason
Benthic Macroinvertebrates	Evaluated	Fail (0/1)	WINOFI
Fish	Evaluated	Fail (0/1)	WINOFI
Overall	Evaluated	Fail	WINOFI	3bc	Assessment was evaluated because it was based on a single sample.

Class BWW2 – Fishkill Assessment

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage/ Thermal	Fish per mile	47b REMAP 25 % fish per mile	> 47b REMAP 25 % fish per mile?	2024 IR 47b expected fish taxa	Fish Taxa Present % (>50% to pass)
1399	09/06/22	25.0	47b	MS/WW	24151	1362	Yes (Pass)	11/12	92% (Pass)
The Class BWW2 use previously resided in Category 5b based on a fish kill that occurred in 2004. This segment’s fish community was sampled in 2022 as part of the DNR fish kill follow-up sampling program. The results from this follow-up sampling and comparison to ecoregion averages suggest that the fish community of this segment is similar to non-fish kill impacted streams. Based on the fish kill follow-up sampling results, the Category for the fish kill assessment was changed from 5b to 3a (not assessed).

Details about the 2004 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/658

For more information on this kill, see the article "Unraveling the Elk Run fish kills" in the March/April 2005 edition of the Iowa Conservationist magazine.

Monitoring and Methods

Assessment Key Dates

11/2/2004

Fish Kill

8/4/2011

Biological Monitoring

9/6/2022

Biological Monitoring

Methods

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