Dibble Creek IA 01-TRK-203
confluence with unnamed tributary in S27 T95N R7W (Fayette Co.) to headwaters in NW 1/4 S36 T95N R7W Winneshiek 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
- 4/25/2019 7:37:42 AM
- Updated
- 7/18/2019 12:26:46 PM
The presumptive Class A1 (primary contact recreation) uses remain “not assessed” due to the lack of information upon which to base an assessment. The presumptive Class B(WW1) aquatic life uses are assessed (evaluated) as “fully supporting” based on DNR/SHL biological sampling conducted in 2013 and 2014.
The presumptive Class B(WW1) aquatic life uses are assessed (evaluated) as “fully supporting”. This evaluated biological assessment of the presumptive Class B(WW1) uses was based on data collected in 2013 and 2014 as part of the DNR/SHL stream biocriteria project. A series of biological metrics that 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 2013 FIBI score was 57 (good) and the 2014 FIBI score was 56 (good). The 2013 BMIBI score was 77 (excellent) and the 2014 BMIBI score was 74 (good). This segment passed the FIBI BIC 2/2 times and passed the BMIBI BIC 2/2 times in the last two years. The aquatic life use support was assessed (evaluated) as fully supporting (=FS), based on a comparison of the FIBI and BMIBI scores with biological impairment criteria (BIC) established from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2004. The FIBI BIC for this ecoregion is 52 and the BMIBI BIC for this ecoregion is 61. Even though this site passed the FIBI and BMIBI BIC's, it is uncertain as to whether or not this segment is meeting the aquatic life criteria because it is a small headwater stream and doesn’t fall in the calibrated watershed size.