Little Cedar River IA 02-CED-576

from confluence with unnamed tributary ( W 1/2 S22 T96N R15W Floyd Co.) to the Floyd/Mitchell co. line at N line S24 T97N R16W Floyd 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 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: 2 - Some of the designated uses are met but there is insufficient data to determine if remaining designated uses are met.
Trend: Unknown
Created: 5/13/2019 1:56:06 PM
Updated: 8/2/2019 1:13:57 PM

Use Support

Class A1

Recreation - Primary contact

Not Assessed

Class BWW1

Aquatic Life - Warm Water Type 1

Fully Supported

Class HH

Human Health -

Not Assessed

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class B(WW1) aquatic life uses are assessed (evaluated) as “fully supported” based on results of DNR/SHL biocriteria sampling in 2009 and 2013. The presumptive Class A1 (primary contact recreation) uses and the Class HH (fish consumption) uses remain "not assessed" due to the lack of data upon which to base an assessment.

Assessment Explanation

The Class B(WW1) aquatic life uses are assessed as “fully supported” based on data collected in 2009 and 2013 as part of the DNR/SHL stream biocriteria project. A series of biological metrics which reflect stream water quality and habitat integrity were calculated from the biocriteria sampling data. The biological metrics are based on the numbers and types of benthic macroinvertebrate taxa and fish species that were collected in the stream sampling reach. The biological metrics were combined to make a fish community index of biotic integrity (FIBI) and a benthic macroinvertebrate index (BMIBI). The indexes rank the biological integrity of a stream sampling reach on a rising scale from 0 (minimum) to 100 (maximum). The 2013 FIBI score was 67 (good) and the BMIBI score was 76 (excellent). The 2009 FIBI score was 80 (excellent) and the BMIBI score was 77 (excellent). The aquatic life use support was assessed as fully supporting (=FS), 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 riffle habitat FIBI BIC for this ecoregion is 65 and the natural substrate BMIBI BIC for this ecoregion is 70. This segment passed the FIBI and BMIBI BICs 2/2 times in the last eight years.

This aquatic life assessment is now considered "evaluated" 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 in the most recent five year period (2012-2016) to be considered “monitored”. This segment had multiple samples collected in the previous eight years (2009-2016).

The presumptive Class A1 (primary contact recreation) uses and the Class HH (fish consumption) uses remain "not assessed" due to the lack of data upon which to base an assessment.

Monitoring and Methods

Assessment Key Dates

9/9/2009

Biological Monitoring

8/19/2013

Biological Monitoring

Methods

150

Monitoring data more than 5 years old

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

330

Fish surveys

380

Quantitative physical habitat assessment