Iowa DNR

Water Quality Assessments

Impaired Waters List

Ioway Creek IA 03-SSK-6459

from unnamed tributary (T85N R25W Sec9 NW Boone Co.) to headwaters (T87N R26W Sec34 Hamilton Co.)

Assessment Cycle
Release Status
Data Collection Period
Overall IR Category
3 - Insufficient data exist to determine whether any designated uses are met.
1/7/2022 11:45:07 AM
1/7/2022 11:46:32 AM
Assessment conducted in accordance with Iowa's 2022 IR methodology
Use Support
Class A1
Not Assessed
Class BWW1
Not Assessed
Impairment Delistings
No delistings for this assessment cycle.
Assessment Summary

The presumptive Class BWW1 use remains assessed as "partially supported" due to a fish kill investigation. All other designated uses were "not assessed". 

Assessment Explanation

Presumptive Class A1 – No Data

Presumptive Class BWW1 - Fishkill Assessment:

The presumptive Class BWW1 use previously resided in IR Category 3b based on the assessment developed for the 2011 fish kill. Because no additional fish kills were reported in this segment for at least 10 years post fish kill (2021), the IR Category for the fish kill assessment was changed from 3b to 3a (not assessed). DNR believes that any impact from the fish kill from which the impairment was based has likely dissipated.

Details about the 2011 fish kill can be found here:

Monitoring and Methods
Assessment Key Dates

None listed


None listed