Maple River IA 06-LSR-1586

from confluence with Silver Cr. (S13 T88N R40W Ida Co.) to confluence with Maple Cr. in S5 T91N R39W Cherokee 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 2016 - 2018
Stream/River Water Quality Data	CY 2016 - 2018
Lake Water Quality Data	CY 2014 - 2018
Biological Sampling Data	CY 2014 - 2018*
Fish Kill Data	CY 2014 - 2018
Fish Tissue Sampling Data	CY 2014 - 2018
Continuous Dissolved Oxygen Sampling Data	CY 2014 - 2018
*Biological sites sampled in both 2013 and 2017 were also assessed.

Open Segment Map
View assessment methodology in new window

Cycle: 2020
Release Status: Final
Overall IR: 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
Trend: Unknown
Created: 9/22/2020 7:33:03 AM
Updated: 10/19/2020 7:25:12 AM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Not Assessed

Class BWW2

Aquatic Life - Warm Water Type 2

Partially Supported

Biological: low fish IBI

Support Level

Partially Supported

Impairment Code

4c - Non-pollutant caused impairment. No TMDL needed.

Cause Magnitude

Slight

Status

Continuing

Source

Hydromodification

Source Confidence

N/A

Cycle Added

2008

Impairment Rationale

Low Biotic Index

Data Source

Biological monitoring: Iowa DNR WQMA

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class BWW2 use remains assessed as "partially supported" based on biological sampling data. All other designated uses were "not assessed".

Assessment Explanation

Sources of Data:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	BIO	See Below	96	Maple River	Aurelia – MR8
Iowa DNR	6	BIO	See Below	97	Maple River	Galva – MR7

Presumptive Class A1 - No Data

Class BWW2 - Biological Sampling:

Fish:

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage/ Thermal	Riffle Stream?	FIBI score	FIBI Class	47a FIBI BIT	FIBI Pass/ Fail
96	8/20/97	105	47a	MO/WW	NA	44	Fair	43	Pass
97	8/20/97	212	47a	MO/WW	NA	35	Fair	43	Fail

Overall:

Community	Assessment Type	Assessment Result	Support Level	Earned IR Category	Actual IR Category	Reason
Fish	Evaluated	Fail (1/2)	Partial	3bc	4c	Assessment is evaluated because it was based on samples not collected in the last five years.
As data age beyond 20 years, their ability to represent current water quality conditions is increasingly suspect. Despite the age of these data, the aquatic life use of this assessment segment will remain “partially supported/evaluated” and will remain in Category 4c of Iowa’s Integrated Report. According to DNR’s assessment/listing methodology, age of data is not a sufficient justification for removing an impairment.

Monitoring and Methods

Assessment Key Dates

8/20/1997

Biological Monitoring

Methods

150

Monitoring data more than 5 years old

315

Regional reference site approach

330

Fish surveys

380

Quantitative physical habitat assessment