Iowa DNR

Water Quality Assessments

Impaired Waters List

Iowa's Integrated Report

The 2024 Integrated Report is currently in draft mode, and is expected to be available after April 2024.

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.
  • EPA Approved - Integrated Report has been approved by the US EPA and is considered Final
  • Draft - Iowa DNR staff are currently working on the assessments. Assessments are developed and reviewed and are not fit for outside review at this point
  • Pending - Pending assessments have been released by Iowa DNR and are awaiting approval by US EPA. Assessments may still change at this point, but are now available for public viewing
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.