Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Little Maquoketa River IA 01-TRK-131

mouth (Dubuque Co.) to confluence with Hogans Br. in S36 T89N R1W Dubuque Co.

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
5/10/2019 9:26:31 AM
Updated
5/10/2019 9:31:12 AM
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 presumptive Class A1 (primary contact recreation) and Class A2 (secondary contact recreation) uses remain "not assessed" due to the lack of information upon which to base an assessment.   The Class B(WW-1) aquatic life uses are assessed (evaluated) as "fully supported" based on results of DNR/SHL biological sampling in 2008, 2012 and 2016.   Fish consumption uses remain "not assessed" due to the lack of fish contaminant monitoring in this stream segment.  

Assessment Explanation

The aquatic life uses are assessed (evaluated) as "fully supporting" based on data collected in 2008, 2012 and 2016 as part of the DNR/SHL stream biological monitoring project. A series of biological metrics which reflect stream water quality and habitat integrity were calculated from the biological sampling data. The biological metrics are based on the numbers and types of benthic macroinvertebrate taxa and fish species 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 2008 FIBI score was 67 (good) and the BMIBI score was 70 (good). The 2012 FIBI score was 66 (good) and the BMIBI score was 62 (good). The 2016 FIBI score was 58 (good) and the BMIBI score was 52 (fair).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 FIBI BIC for this ecoregion is 52 and the BMIBI BIC for this ecoregion is 61. This segment passed the FIBI BIC 3/3 times and passed the BMIBI BIC 2/3 times in the last nine years. The biological impairment criteria were determined from a statistical analysis of biological data collected at stream ecoregion reference sites from 1994-2008.

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 over the most recent five-year period (2012-2016) to be considered “monitored”. This segment had multiple samples collected in 2012-2016; however, the 2008 sample results were needed to complete the BMIBI assessment.

The presumptive Class A1, Class A2 and Class HH uses remain "not assessed" due to the lack of data upon which to base an assessment.

Monitoring and Methods
Assessment Key Dates
8/19/2008
Biological Monitoring
9/25/2012
Biological Monitoring
9/13/2016
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