2024 Pending assessment for Long Dick Creek

Long Dick Creek IA 03-SSK-2007

N. line of S34 (SE1/4) T86N R23W Hamilton Co to headwaters in NE1/4 S8 T87N R23W Hamilton 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: 12/8/2023 1:52:59 PM
Updated: 2/2/2024 7:11:04 AM

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

Use Support

Class A1

Presumptive Use

Not Supported

Bacteria: Indicator Bacteria- E. coli

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

2010

Impairment Rationale

Single-sample maximum criterion exceeded in significantly > 10% of samples

Data Source

TMDL monitoring: Iowa DNR

TMDL Priority

Tier IV

Class BWW1

Presumptive Use

WINOFI

Biological: low fish IBI

Support Level

Water in Need of Further Investigation (WINOFI)

Impairment Code

3b-u - Use potentially biologically impaired based on uncalibrated IBI metrics.

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2010

Impairment Rationale

Low Biotic Index

Data Source

Biological monitoring: Iowa DNR WQMA

Impairment Delistings

Cycle Added	Class	Cause	Data Source	Rationale
2006	Class BWW1	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
2014	Class BWW1	Fish Kill: Caused By Pesticides	Biological monitoring: Iowa DNR fish kill follow-up	New data: recovery of fish community from pollutant-caused fish kill

Documentation

Assessment Summary

The presumptive Class A1 use was assessed as "not supported" due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The presumptive Class BWW1 use was assessed as “WINOFI” based on historical biological sampling. However, biological sampling data collected in 2022 showed recovery of the fish community in this segment from the fish kills. Based on the 2022 fish sampling data, the 5b fish kill impairments were de-listed.

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY 2008 – 2009	11400004	Long Dick Creek near Ellsworth	Site ldc-2
Iowa DNR	6	BIO	See Below	691	Long Dick Creek	Ellsworth – LDC2

Presumptive Class A1 - Indicator Bacteria: Historical

Site ID	Data Source ID	# Samples / # Years	2008 Geometric Mean	2009 Geometric Mean	Annual Geometric Mean Violation	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
11400004	6	26 / 2	369	175	Yes	15	58%	Yes	Evaluated	Not

Presumptive Class BWW1 - 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
691	10/6/08	16	47b	MS	Art Sub	71	Good	62	Pass

Fish:

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	Riffle Stream?	FIBI score	FIBI Class	47b FIBI BIT	FIBI Pass/Fail
691	10/6/08	16	47b	MS	Yes	24	Poor	53	Fail

Overall:

Community	Assessment Type	Assessment Result	Support Level	IR Category	Reason
Benthic Macroinvertebrates	Evaluated	Pass (1/1)	Full
Fish	Evaluated	Fail (0/1)	WINOFI		Assessment was evaluated because the drainage area of the
Overall	Evaluated	Fail	WINOFI	3bu	site was smaller than the calibrated range.

Presumptive Class BWW1 – Fish kill 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)
1389	08/25/22	21.9	47b	MS/WW	9810	1362	Yes (Pass)	11/12	91.6% (Pass)
The presumptive Class BWW1 use previously resided in Category 5b based on 2004 and 2011 fish kills. 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).

More details about the 2011 fish kill can be found here:https://programs.iowadnr.gov/fishkill/Events/834

More details about the 2004 fish kill can be found here:https://programs.iowadnr.gov/fishkill/Events/599

Monitoring and Methods

Assessment Key Dates

8/4/2011	Fish Kill
7/28/2009	Monitoring End
10/6/2008	Biological Monitoring
1/7/2008	Monitoring Start
4/19/2004	Fish Kill
8/25/2022	Biological Monitoring

Methods

140	Incidence of spills and/or fish kills
150	Monitoring data more than 5 years old
200	Physical/Chemical Monitoring
315	Regional reference site approach
320	Benthic macroinvertebrate surveys
330	Fish surveys
420	Indicator bacteria monitoring

Water Quality Assessments

Impaired Waters List

Long Dick Creek IA 03-SSK-2007

Assessment Summary

Assessment Explanation

Assessment Key Dates

Methods