Impaired waters

303(d) and integrated reporting

The 303(d) List of Water-Quality-Limited Segments Requiring TMDLs — 303(d) List and Colorado’s Monitoring and Evaluation List (M&E List) are included in Regulation 93.

This list fulfills Section 303(d) of the federal Clean Water Act, which requires states to submit to the U.S. Environmental Protection Agency (EPA) a list of waters for which technology-based effluent limitations and other required controls aren’t stringent enough to implement water quality standards.

• Regulation #93.

  • Regulation #93 Electronic Dashboard.

• 305(b): Integrated Water Quality Monitoring and Assessment Report.

  • 2024 Integrated Report StoryMap

    • 2024 Integrated Report - Use Attainment Table for Rivers

    • 2024 Integrated Report - Use Attainment Table for Lakes

    • 2024 Integrated Report - Delisting Table

  • 2022 Integrated Report Story Map.

  • 2022 Integrated Report (PDF)

• Completed Total Maximum Daily Load information.