Iowa DNR

Water Quality Assessments

Impaired Waters List

Modern Integrated Report Summaries

Beginning with the 2016 assessment cycle, the format of assessments was changed from assessing the overall status of a waterbody segment to a more detailed assessment of individual use attainment for each segment. This change implemented US EPA's guidelines for assessments and required a change in database structure to support the new assessment methodology. These assessments use current EPA guidelines.

Legacy Assessment Summaries

Assessments prior to the 2016 cycle are referred to as "Legacy Assessments". Summary information for legacy assessment cycles is limited, as legacy assessments used the older assessment methodology.

Older Assessment Summaries

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.

The original format of the individual assessments was preserved as much as possible, as that was the official submission for those 305(b) and 303(d) reports.