Grannis Creek IA 01-VOL-322
mouth (S30 T93N R7W Fayette Co.) to west line of S36 T93N R8W Fayette Co.
- Cycle
- 2020
- Release Status
- Final
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 10/2/2020 12:47:43 PM
- Updated
- 10/15/2020 1:25:02 PM
The presumptive Class A1 use remains assessed as “partially supported” due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The presumptive Class A2 use remains assessed as "fully supported” based on indicator bacteria (E. coli) monitoring data. The Class BCW1 use remains assessed as "fully supported" based on water quality monitoring data and on the trout reproduction in Iowa streams summary prepared by the DNR Fisheries Bureau. All other designated uses were "not assessed".
Sources
of Data: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2012-2014 15330005 Grannis Cr @ Fox Road (GRA10) Presumptive Class
A1 - Indicator Bacteria: Historical Site ID Data Source ID # Samples / # Years 2012 Geometric Mean 2013 Geometric Mean 2014 Geometric Mean Annual Geometric Mean Violation # Violations % Violations Significantly >10% Violations Assessment Type Support Level 15330005 6 24 / 3 267 152 203 Yes 10 42% Yes Evaluated Partial Presumptive Class
A2 - Indicator Bacteria: Historical Site ID Data Source ID # Samples / # Years 2012 Geometric Mean 2013 Geometric Mean 2014 Geometric Mean Annual Geometric Mean Violation # Violations % Violations Significantly >10% Violations Assessment Type Support Level 15330005 6 24 / 3 267 152 203 No 2 8% No Evaluated Full Class BCW1 -
Conventional Parameters: Historical Site ID Data Source ID Parameter Name # Samples / # Years Maximum Value Mean Value Median Value # Acute / Chronic Violations % Acute/ Chronic Violations Significantly >10% Violations Assessment Type Support Level 15330005 6 Ammonia 16 / 2 0.16 0.06 0.05 0 / 0 0%
/ 0% No Evaluated Full 15330005 6 Chloride 16 / 2 33 31 31 0 / 0 0%
/ 0% No Evaluated Full 15330005 6 Dissolved oxygen 24 / 3 10 8.5833 8 NA / 2 NA /
8% No Evaluated Full 15330005 6 pH 24 / 3 8.63 8.32 8.34 0 / NA 0%
/ NA No Evaluated Full 15330005 6 Temperature 24 / 3 17.2 11.0042 11.5 0 / 0 0%
/ 0% No Evaluated Full Class BCW1 –
Trout Natural Reproduction: Based on the January 2020 trout reproduction in Iowa streams summary prepared by the DNR Fisheries Bureau, the Class BCW1 coldwater aquatic life use of Grannis Creek was assessed as "fully supported". According to the updated summary, this stream was placed in Category I: streams that exhibit consistent natural reproduction and maintain a wild population of one or more trout species without any stocking.
Class HH - No
Data