Section 401 Water Quality Certification: Protecting Missouri's Wetlands

Water Protection Program fact sheet
Division of Environmental Quality Director: Ed Galbraith

For much of our history, many people thought wetlands were useless swamps filled with mosquitoes. Today, we know that wetlands are among the most productive ecosystems in the world, comparable to rain forests and coral reefs. A rich source of diversity, wetlands are home to a wide variety of plant and animal species that are crucial to a healthy environment.

Many species of birds and mammals rely on wetlands for food, water and shelter, especially during migration and breeding seasons. People depend on wetlands, too. Wetlands filter pollutants from our drinking water, provide natural flood control and help prevent our shorelines from eroding. Wetlands are an important part of our natural resources, worthy of our respect and deserving of our protection.

Unfortunately, more than half of the wetlands in the lower 48 states have already been lost as a result of drainage and filling. In its early history, Missouri had as much as 4.8 million acres of wetlands. By 1980, the number of wetlands in the state had dropped dramatically, to 643,000 acres. Protecting and restoring our wetlands is one of today’s most critical environmental challenges.

Protecting wetlands

The federal government protects wetlands through regulations like Section 404 of the Federal Clean Water Act.

Section 401 of the Clean Water Act gives the states the authority to protect wetlands by regulating certain activities.  Through the issuance of a Section 401 Water Quality Certification, the state ensures that a proposed project will not violate Missouri  water quality standards. Any activity involving the placement of dredged or fill material into waters of the state (including wetlands) must have a 401 certification from the department. Some of these activities might include the replacement of a low water stream crossing, construction of a levee, dams or dikes, and many other activities that require working below the ordinary high water mark of a stream. When a 401 certification is issued it becomes part of the 404 permit issued by the U.S. Army Corps of Engineers. 

If the Coprs determines a 404 Permit is needed, a 401 Certification from the department is needed as well.  The applicant of a 404/401 permit is required to avoid and/or minimize the project’s adverse impacts to wetlands and other waters of the state. If adverse impacts cannot be avoided, the department  will require compensatory mitigation for those impacts.

Applying for 401 Certification

Applying for a Section 401 Water Quality Certification is a two-step process.

For more information
Department of Natural Resources email:

Section 404 - Federal Clean Water Act :

Section 401 - Federal Clean Water Act:

Section 404 Nationwide Permit Information:

Map of U.S. Army Corps of Engineers districts:

Use the online map to determine which U.S. Army Corps of Engineers district regulatory office you may need to call about a Section 404 permit.

U.S. Army Corps of Engineers - District Regulatory office phone numbers

•       Kansas City District - Kansas City Regulatory Office (816) 389-3990

•       Kansas City District - Missouri State Regulatory Office (Jefferson City) (573) 634-2248

•       Kansas City District - Truman Satellite Office (Warsaw) (660) 438-6697

•       Little Rock District (501) 324-5295

•       Memphis District (901) 544-3473

•       Rock Island District (309) 794-5057

•       St. Louis District (314) 331-8575