Dry Branch IA 01-TRK-2002
confluence with unnamed tributary in the N 1/2 S4 T95N R8W Fayette Co. to headwaters in SW1/4 S33 T97N R8W Winneshiek Co.
The presumptive Class A1 use remains assessed as “not supported” due to violations of Iowa water quality criteria for indicator bacteria (E. coli). The presumptive Class BWW1 use was assessed as "not supported" based on the occurrence of two fish kills in this segment in the last five years.
Data
Sources: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2012-2014 15960015 Dry Branch at 110 St DBR30 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 15960015 6 25 / 3 1700 3702 183 Yes 18 72% Yes Evaluated Not The presumptive Class BWW1 aquatic life use assessment based on the 2021 and
2024 fish kills placed this segment in Category 4d. The fish kills were caused
by a “pollutant” or were suspected to be caused by a “pollutant”; therefore,
the presumptive Class BWW1 use was considered impaired. However, because
restitution for the fish killed during both fish kills was received, the presumptive
Class BWW1 use was placed in Category 4d (impaired but TMDL not required). DNR
feels that (1) TMDLs should not be required for a fish kill caused by a
one-time illegal or unauthorized release of a pollutant where enforcement
action was taken and (2) enforcement action is more appropriate and effective
for addressing a spill-related impairment than the TMDL process. Details about the 2024 fish kill can be found here: https://programs.iowadnr.gov/fishkill/events/1064
Presumptive Class A1 - Indicator Bacteria:
Presumptive Class BWW1 – Fish kill Assessment:
Details about the 2021 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/1014