Winnebago River IA 02-WIN-831

from confluence with Pike Run (S25 T99N R24W Winnebago Co.) to the Iowa/Minnesota state line

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 2014 - 2016
Stream/River Water Quality Data	CY 2014 - 2016
Lake Water Quality Data	CY 2012 - 2016
Biological Sampling Data	CY 2012 - 2016*
Fish Kill Data	CY 2012 - 2016
Fish Tissue Sampling Data	CY 2012 - 2016
Continuous Dissolved Oxygen Sampling Data	CY 2012 - 2016
*Biological sites sampled in both 2011 and 2015 were also assessed.

Open Segment Map
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Cycle: 2018
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Unknown
Created: 5/14/2019 9:12:25 AM
Updated: 5/14/2019 9:16:23 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 & invert IBIs- cause unknown

Support Level

Partially Supported

Impairment Code

5b-v - Biological - verified

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2004

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" due to the lack of information upon which to base an assessment. The Class BWW-2 (aquatic life) uses are assessed (monitored) as "partially supported" based on results of DNR/SHL biological sampling in 2012 and 2015.

Assessment Explanation

The Class B(WW2) aquatic life uses are assessed (monitored) as “partially supported” based on data collected in 2012 and 2015 as part of the DNR/SHL stream biocriteria project. The 2015 FIBI score was 24 (poor) and the BMIBI score was 57 (good). The 2012 FIBI score was 23 (poor) and the BMIBI score was 45 (fair). The aquatic life use support assessment was assessed 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 32 and the BMIBI BIC for this ecoregion is 62. This segment passed the FIBI BIC 0/2 times and passed the BMIBI BIC 0/2 times in the past five years.

This aquatic life assessment is now considered "monitored" based on a change in the 2010 DNR assessment methodology. DNR now requires a segment have two or more biological samples collected from the segment in multiple years over a recent five-year period to be considered “monitored”. This segment had multiple samples collected in the previous five years (2012-2016).

Monitoring and Methods

Assessment Key Dates

7/30/2012

Biological Monitoring

9/28/2015

Biological Monitoring

Methods

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

330

Fish surveys

380

Quantitative physical habitat assessment