Burr Oak Creek IA 02-CED-580

mouth (S12 T98N R16W Mitchell Co.) to Mitchell County Road T46 at W line S10 T98N R16W Mitchell 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 2012 - 2014
Stream/River Water Quality Data	CY 2012 - 2014
Lake Water Quality Data	CY 2010 - 2014
Biological Sampling Data	CY 2010 - 2014*
Fish Kill Data	CY 2010 - 2014
Fish Tissue Sampling Data	CY 2010 - 2014
Continuous Dissolved Oxygen Sampling Data	CY 2010 - 2014
*Biological sites sampled in both 2009 and 2013 were also assessed.

Open Segment Map
View assessment methodology in new window

Cycle: 2016
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Unknown
Created: 9/15/2016 2:40:01 PM
Updated: 10/5/2016 7:30:58 AM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Not Assessed

Class BWW2

Aquatic Life - Warm Water Type 2

Partially Supported

Biological: low aquatic macroinvertebrate IBI

Support Level

Partially Supported

Impairment Code

5b-v - Biological - verified

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2006

Impairment Rationale

Low Biotic Index

Data Source

Biological monitoring: Iowa DNR WQMA

TMDL Priority

Tier IV

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The presumptive Class A1 (primary contact recreation) uses remain "not assessed" (IR 3a) due to the lack of information upon which to base an assessment. The Class B(WW-2) aquatic life uses are assessed (monitored) as "partially supported" (IR 5b-v) based on results of IDNR/SHL biological sampling conducted in 2011, 2012 and 2013.

Assessment Explanation

The Class B(WW2) aquatic life uses remain assessed (monitored) as “partially supporting” based on data collected in 2011, 2012 and 2013 as part of the IDNR/SHL stream biocriteria project. The 2011 FIBI score was 69 (good) and the BMIBI score was 78 (excellent). The 2012 FIBI score was 62 (good) and the BMIBI score was 69 (good). The 2013 FIBI score was 76 (excellent) and the BMIBI score was 57 (good). The aquatic life use support was assessed (evaluated) as partially supporting (=PS), based on a comparison of the FIBI and BMIBI scores with biological impairment criteria (BIC) established for previous Section 305(b) reports. The biological impairment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2008. The non-riffle habitat FIBI BIC for this ecoregion is 44 and the natural substrate BMIBI BIC for this ecoregion is 70. This segment passed the FIBI BIC 3/3 times and the BMIBI BIC 1/3 times in the last five years (2010-2014).

This aquatic life assessment is considered "monitored" because there were two or more samples collected from this segment in multiple years over a recent five-year period (2010-2014).

Monitoring and Methods

Assessment Key Dates

8/3/2011

Biological Monitoring

7/30/2012

Biological Monitoring

8/15/2013

Biological Monitoring

Methods

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

330

Fish surveys

380

Quantitative physical habitat assessment