Tap on the image to access location, classification and designated uses of Missouri waterbodies.

The goal of the federal Clean Water Act (CWA) is to restore and maintain the chemical, physical and biological integrity of the nation’s waters. Water quality standards establish the water quality goals for a specific waterbody, or portion of that waterbody. For more information about federal requirements, visit the U.S. Environmental Protection Agency's Water Quality Standards: Regulations and Resources website. 

Missouri’s water quality standards, which are defined in Code of State Regulations 10 CSR 20-7.031, describe the desired condition of Missouri's waterbodies and the means by which those conditions will be protected or reached. Water quality standards consist of the following core components:

  • Designated use or uses of a waterbody
  • Criteria necessary to protect the designated uses
  • Antidegradation requirements 

The goal for water quality standards is protecting water uses through applying criteria. The level of protection given to a stream, river or lake depends on the expected, or "designated use(s)," of that water, such as "recreation". When the department assigns designated uses to a waterbody, it is considered “classified” and listed in Missouri’s water quality standards. Water quality criteria are expressed as concentrations, loads or narrative statements. Antidegradation policy requires actions to maintain and protect high quality waters and existing water quality. 

The department's Water Quality Standards Map Viewer is an online ArcGIS application that shows classification and designated uses of Missouri waterbodies.