Iowa DNR
Iowa DNR
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Water Quality Assessments
Impaired Waters List

Iowa's Integrated Report

The 2026 Integrated Report is currently in progress and will be available for viewing when the cycle is released for public commment.
  • Methodology Review
  • Data Processing
  • Draft IR
  • Public Comment
  • Submitted to EPA R7
  • EPA Response
  • Final IR

Beginning with the 2016 assessment cycle, the assessment format 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.
2026
In Progress
2024
EPA Approved 12/30/2024 2022
EPA Approved 4/29/2022 2020
EPA Approved 5/14/2021 2018
EPA Approved 3/24/2020 2016
EPA Approved 1/16/2018

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.
2014 2012 2010 2008 2006 2004

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 limited amount of information and its incompatibility with the current assessment format, no summarization is provided for these assessment cycles.

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

Assessment Methodologies

Finalized Integrated Report assessment methodologies are available on the State Library of Iowa website.

2024 Methodology 2022 Methodology 2020 Methodology 2018 Methodology 2016 Methodology 2014 Methodology 2012 Methodology 2010 Methodology 2008 Methodology 2006 Methodology 2004 Methodology 2002 Methodology 2000 Methodology