Total Maximum Daily Loads (TMDLs)

Impaired waters are ranked as high, medium or low priority for TMDL development. For impairments ranked as high priority, a specific year is given for when a TMDL may be developed. All priority rankings and development schedules are reevaluated with each new 303(d) list of impaired waters.

• Prioritization Framework for Development of Total Maximum Daily Loads
• TMDL Alternative - Category 5-alt Components

Impairments identified as high priority in the 2022 Section 303(d) list and as scheduled to begin development in 2022 will be provided to EPA for including in the national bridge metric goals. These are called “bridge metrics” because this is just a temporary metric bridging the gap between the 2013-2022 and the 2024-2034 metrics. Beginning with the 2024 Section 303(d) list, a more formalized national 303(d) framework will be implemented. The Missouri water bodies included in the bridge metrics are identified by an asterisk next to the Water Body Identification Number in the TMDLs Under Development tab.

• 2022 Section 303(d) List - TMDL Bridge Metrics

All draft TMDLs are made available for review and comment during a 45-day public comment period. Email public comments or questions about TMDLs to tmdl@dnr.mo.gov.

TMDL Documents Under Development

Approved TMDLs are the final TMDL document, as approved by the U.S. Environmental Protection Agency after public notice and comment. Access to final TMDL documents are provided below in two different formats. The only difference is the amount of additional information provided about the impaired water body or lake.

• Missouri Approved or Established Total Maximum Daily Loads - A PDF document containing minimal information about the impaired water body or lake and links to the final TMDL document and implementation document, if available.
• Impaired Waters and TMDL Map Viewer - An online ArcGIS map that shows locational data for the impaired water body or lake. Detailed information about the water body is accessed by clicking on the line or polygon segments on the map. Included in the water body information are links to the final TMDL document and implementation document, if available. Although the department compiled the map information, no warranty, expressed or implied, is made by the department as to the accuracy of the data and related materials.
• Tools and Resources for Watershed Planning and Improvement - A TMDL identifies water quality problems, possible causes and provides targets for restoration. However, actual water quality improvements are often dependent upon voluntary actions and support from local communities and landowners residing within the watershed.