Shoal Creek IA 05-CHA-1342

IA/MO ln to trib S28T68NR19W Appanoose

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.

Open Segment Map
View assessment methodology in new window

Cycle: 2022
Release Status: Final
Overall IR: 3 - Insufficient data exist to determine whether any designated uses are met.
Trend: Unknown
Created: 12/10/2021 10:08:49 AM
Updated: 1/25/2022 3:23:04 PM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Not Assessed

Class BWW2

Aquatic Life - Warm Water Type 2

WINOFI

Biological: low aquatic macroinvertebrate IBI

Support Level

Further Investigation Needed

Impairment Code

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

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2018

Impairment Rationale

Low Biotic Index

Data Source

Biological monitoring: Iowa DNR WQMA

Organic Enrichment: Low Dissolved Oxygen

Support Level

Further Investigation Needed

Impairment Code

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

Cause Magnitude

Slight

Status

New

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2022

Impairment Rationale

Significantly > 10% of days fail to meet 16-hour criteria

Data Source

Ambient monitoring: Iowa DNR-continuous

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class BWW2 use was assessed as “WINOFI” based on biological sampling data and continuous dissolved oxygen monitoring data. 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	1263	Shoal Creek	Exline – REMAP #289
Iowa DNR	6	BIO	See Below	218	Shoal Creek	Exline

Presumptive Class A1 - No Data

Class BWW2 - Biological Sampling:

Benthic Macroinvertebrates:

Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	BM Sample Gear	BMIBI score	BMIBI Class	40a BMIBI BIT	BMIBI Pass/Fail
1263	7/29/20	66	40a	MO	Art Sub	36	Fair	41	Fail
218	7/29/20	61.8	40a	MO	Art Sub	43	Fair	41	Pass
218	8/29/16	61.8	40a	MO	Art Sub	28	Poor	41	Fail
218	7/21/16	61.8	40a	MO	Art Sub	44	Fair	41	Pass

Fish:

Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	Riffle Stream?	FIBI score	FIBI Class	40a FIBI BIT	FIBI Pass/Fail
1263	7/29/20	66	40a	MO	NA	40	Fair	33	Pass
218	7/29/20	61.8	40a	MO	NA	35	Fair	33	Pass
218	8/29/16	61.8	40a	MO	NA	47	Fair	33	Pass

Overall:

Community	Assessment Type	Assessment Result	Support Level	IR Category	Reason
Benthic Macroinvertebrates	Evaluated	Fail (2/4)	Not
Fish	Evaluated	Pass (3/3)	Full	3bc	Assessment was evaluated because the BMIBI results were inconclusive.
Overall	Evaluated	Fail	WINOFI		A simple majority of samples need to fail for a Category 5 impairment.

Class BWW2- Continuous DO Monitoring:

Site ID	Data Source ID	# Days Monitoring (2016/2017/2018/ 2019/2020)	DO Criteria Type	# 2016 violations / Violations needed for impairment	# 2017 violations / Violations needed for impairment	# 2018 violations / Violations needed for impairment	# 2019 violations / Violations needed for impairment	# 2020 violations / Violations needed for impairment	Violates Annual Significantly >10% Rule?	Assessment Type	Support Level
			24 hr	13/11	NA	NA	NA	NA	Yes
218	6	71/0/0/0/0	16 hr	14/11	NA	NA	NA	NA	Yes	Evaluated	WINOFI

Monitoring and Methods

Assessment Key Dates

8/29/2016

Biological Monitoring

7/21/2016

Biological Monitoring

7/29/2020

Biological Monitoring

Methods

222

Non-fixed-station monitoring (conventional during key seasons and flows)

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

330

Fish surveys

380

Quantitative physical habitat assessment