Keg Creek IA 06-WED-1687
from confluence with Little Keg Cr. (S27 T75N R42W Pottawattamie Co.) to confluence with unnamed tributary in S35 T78N R41W Harrison Co.
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 are assessed (evaluated) as "partially supporting" based on data collected in 2002 and 2012 as part of the DNR/SHL stream REMAP and follow-up sampling projects and on data collected in 2002 as part of a DNR Fisheries stream sampling project: Cold Springs Fish Management.
The Class B(WW2) aquatic life uses are assessed (evaluated) as "partially supporting" based on data collected in 2002 and 2012 as part of the DNR/SHL stream REMAP and follow-up sampling projects and on data collected in 2002 as part of a DNR Fisheries stream sampling project: Cold Springs Fish Management. 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 2002 REMAP FIBI score was 30 (fair) and the BMIBI score was 47 (fair). The 2002 DNR Fisheries FIBI score was 23 (poor). The 2012 FIBI score was 3 (poor) and the BMIBI score was 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 0/3 times and passed the BMIBI BIC 0/3 times in the last 15 years. This aquatic life assessment is considered "evaluated" because there were not two or more samples collected from this segment in multiple years over a recent 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). However, despite this change in assessment methodology and type, this waterbody was previously on Iowa’s Section 303(d) list and thus remains on Iowa’s Section 303(d) list of impaired waters (IR Category 5b-t).