Elkhorn Creek IA 05-NSH-1901
trib Shelby Co to headwaters in Audubon 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
- 7/29/2019 10:29:00 AM
- Updated
- 7/29/2019 10:29:35 AM
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 remain assessed (evaluated) as “fully supporting" based on data collected in 2002 as part of an DNR Fisheries stream sampling project: Cold Springs Fish Management.
The presumptive Class B(WW1) aquatic life uses remain assessed (evaluated) as “fully supporting” based on data collected in 2002 as part of an 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 Fisheries sampling data. The biological metrics are based on the numbers and types 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). The index ranks the biological integrity of a stream sampling reach on a rising scale from 0 (minimum) to 100 (maximum). The 2002 FIBI scores were 40, 50 (fair). The aquatic life use support was assessed (evaluated) as fully supporting (=FS), based on a comparison of the average FIBI score 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. This segment passed the FIBI BIC 2/2 times in 2002. 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 2002; however, the multiple samples were not collected during a recent five-year period and were not collected in multiple years. Additionally, because these data are now considered too old (greater than five years) to accurately characterize current water quality conditions, the assessment category is considered “evaluated” (indicating an assessment with relatively lower confidence) as opposed to "monitored" (indicating an assessment with relatively higher confidence). Despite this change in assessment methodology and type, this waterbody remains in IR Category 2a.