Lotts Creek IA 05-GRA-1376
IA/MO line (S24 TT67N R29W Ringgold Co.) to confluence with Tuckers Cr. in S12 T67N R29W Ringgold 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 biological data collected in 2003, 2010 and 2014 as part of the DNR/SHL stream biocriteria project.
The Class B(WW2) aquatic life uses are assessed (evaluated) as “partially supporting” based on biological data collected in 2003, 2010 and 2014 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 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 2003 FIBI score was 22 (poor) and the BMIBI score was 53 (fair). The 2010 FIBI score was 39 (fair) and the BMIBI score was 60 (good). The 2014 FIBI score was 22 (poor) and the BMIBI score was 34 (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 FIBI BIC for this ecoregion is 33 and the BMIBI BIC for this ecoregion is 41. This segment passed the FIBI BIC 1/3 times and passed the BMIBI BIC 2/3 times in the last 14 years. The biological impairment criteria were determined from a statistical analysis of 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 a recent five-year period to be considered “monitored”. This segment had multiple samples collected in the previous 14 years; however, the multiple samples were not collected during 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). However, despite this change in assessment methodology, this waterbody was previously on Iowa’s Section 303(d) list and thus remains on Iowa’s Section 303(d) list of impaired waters until a monitored assessment can be completed.