Whitewater Creek IA 01-NMQ-103
mouth (S10 T86N R1W Jones Co.) to confluence with Curran Branch in S12 T87N R1W Dubuque Co.
- Cycle
- 2020
- Release Status
- Final
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 6/11/2020 9:07:17 AM
- Updated
- 10/15/2020 6:15:50 AM
The presumptive Class A1 use was assessed as “not supported” due to levels of indicator bacteria (E. coli ) that exceeded Iowa’s geometric mean criterion. The Class BWW1 use remains assessed as "not supported" based on a fish kill investigation and on information from the report "Statewide Assessment of Freshwater Mussels (Bivalva, Unionidae) in Iowa Streams" by Arbuckle et al. (2000). 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 2012-2013 15310001 Whitewater Creek Class A1 -
Indicator Bacteria: Historical Site ID Data Source ID # Samples / # Years 2012 Geometric Mean 2013 Geometric Mean Annual Geometric Mean Violation # Violations % Violations Significantly >10% Violations Assessment Type Support Level 15310001 6 14 / 2 717 4404 Yes 13 93% Yes monitored Not
Class BWW1 -
Fish Kill: The Class BWW1 use assessment based on the 2016 fish kill placed this segment in Category 5b. The fish kill was caused by a “pollutant” or was suspected to be caused by a “pollutant”; therefore, the Class BWW1 use was considered impaired. Because the source of the pollutant was not identified and/or the enforcement actions taken against the responsible party have not been resolved, the Class BWW1 use was placed in Category 5b. Due to uncertainty regarding the recovery of the aquatic life following the fish kill, any existing fish kill 5b impairment will remain in Category 5b until more recent sampling has shown recovery of the aquatic community or the responsible party has paid restitution. Details about the 2016 fish kill can be found here:https://programs.iowadnr.gov/fishkill/Events/916 Class
BWW1 – Freshwater Mussel Sampling: Freshwater Mussel Survey Avg. # Freshwater Mussel Species Avg. # Freshwater Mussel Species
Increase/Decrease Avg % Freshwater Mussel Species
Increase/Decrease Assessment Type Support Level IR Category 1984-85
(Frest 1987) 2 sites 5 1998-99
(Arbuckle et al. 2000) 2 sites 0 -5 -100% Evaluated Not 5b As
presented by Arbuckle et al. (2000), the potential causes of declines in
species richness of Iowa's freshwater mussels include siltation,
destabilization of stream substrate, stream flow instability, and high
instream levels of nutrients (phosphorus and nitrogen). Their study also
suggested the importance of stream shading provided by riparian vegetation to
mussel species richness. Class
HH - No Data