Publications

Current Assessment Methodology Documents

Methodology for Iowa’s 2024 Water Quality Assessment, Listing, and Reporting Pursuant to Sections 305(b) and 303(d) of the Federal Clean Water Act

Previous Assessment Methodology Documents

• Methodology for Iowa’s 2022 Water Quality Assessment, Listing, and Reporting Pursuant to Sections 305(b) and 303(d) of the Federal Clean Water Act
• Methodology for Iowa’s 2020 Water Quality Assessment, Listing, and Reporting Pursuant to Sections 305(b) and 303(d) of the Federal Clean Water Act
• Methodology for Iowa’s 2018 Water Quality Assessment, Listing, and Reporting Pursuant to Sections 305(b) and 303(d) of the Federal Clean Water Act
• Methodology for Iowa’s 2016 Water Quality Assessment, Listing, and Reporting Pursuant to Sections 305(b) and 303(d) of the Federal Clean Water Act

GIS Datasets

• Impaired Waters
• Iowa DNR Geospatial REST services- water quality

Other Documentation

• Surface Water Classification - 2019
  • List of Iowa surface waters and their use designations.
• Iowa Administrative Code Chapter 61 - Water Quality Standards
• Iowa's Credible Data Law