Iowa DNR
ADBNet

Water Quality Assessments

Impaired Waters List

1994 305(b) Legacy Assessment Summary

Assessments for cycles prior to 2004 were conducted using a different methodology than those conducted for later cycle. This methodology differed significantly from more recent assessment procedures, and do not contain the same detailed information newer assessments have. Additionally, these assessments were conducted before the introduction of the "integrated report”, which combined both the Section 305(b) report and Section 303(d) list. Therefore, these assessments do not use the familiar "Overall Assessment Category" designations.

Due to the changes that have occurred over the years, a more limited summarization is provided for these assessment cycles.

Assessment Results

The number of assessments the Iowa DNR can make in a given cycle are limited by budgets and staffing resources. The following charts show the proportions to which each waterbody type meets WQ standards, and the percentage that has been assessed in this cycle.

Rivers and Streams
Lakes and Reservoirs
Wetlands