Iowa DNR
Iowa DNR

ADBNet

Water Quality Assessments
Impaired Waters List

Indian Creek IA 05-NSH-1425

mouth (S17 T75N R37W Cass Co.) to confluence with Wolf Cr. in S35 T79N R37W Shelby Co.

Overall IR
3 - Insufficient data exist to determine whether any designated uses are met.
Trend
Unknown
Created
5/16/2019 12:27:59 PM by
Updated
5/16/2019 12:30:56 PM by
Use Support
Class A1
Recreation - Primary contact
Not Assessed
Class BWW2
Aquatic Life - Warm Water Type 2
WINOFI
Impairment Code
3b-c - Use potentially biologically impaired based on calibrated IBI metrics.
Cause Magnitude
Slight
303(d) Listing Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2010
Impairment Rationale
Low Biotic Index
Data Source
Biological monitoring: Iowa DNR WQMA
General Use
General Use water -
Not Assessed
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 B(WW2) aquatic life uses remain assessed (evaluated) as "partially supported" based on results of 1996, 2002 and 2011 DNR/SHL biological and DNR Fisheries sampling in 2002.

Assessment Explanation

The Class B(WW2) aquatic life uses remain assessed (evaluated) as “partially supporting” based on biological data collected in 1996, 2002 and 2011 as part of the DNR/SHL stream biocriteria project and on data collected in 2002 as part of an DNR Fisheries stream sampling project: Cold Springs Fish Management. The 1996 FIBI score was 21 (poor) and the BMIBI score was 51 (fair). The 2002 FIBI score was 34 (fair) and the BMIBI score was 65 (good). The 2011 FIBI score was 26 (fair) and the BMIBI score was 52 (fair). The 2002 DNR Fisheries FIBI scores were 23 (poor) and 41 (fair). The aquatic life use support 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 FIBI BIC for this ecoregion is 31 and the BMIBI BIC for this ecoregion is 54. This segment passed the FIBI BIC 2/5 times and passed the BMIBI BIC 1/3 times in the last 21 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 over a recent five-year period to be considered “monitored”. This segment had multiple samples collected in the previous 21 years; however, the multiple samples were not collected during a five-year period. According to DNR’s assessment/listing methodology, impairments based on “evaluated” assessments are of lesser confidence and are thus not appropriate for Section 303(d) listing (Category 5 of the Integrated Report). DNR does, however, consider these impairments as appropriate for listing under either Category 2b or 3b of the Integrated Report (waters potentially impaired and in need of further investigation).

Monitoring and Methods
Assessment Key Dates
10/15/1996
Biological Monitoring
7/23/2002
Biological Monitoring
9/22/2011
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