The Clean Water Act (CWA) of 1972 requires the Federal Highway Administration (FHWA) and the Missouri Department of Transportation (MoDOT) to evaluate every project and determine whether the project could have a negative impact on any waters of the U.S. including wetlands, streams, and special aquatic sites.  FHWA and MoDOT must use the best available scientific information and the 1987 Corp of Engineers’ Wetland Delineation Manual to evaluate their projects and they must provide data to support their determination of impact. 

Under the Sections 401 and 404 of the CWA, no action can be taken that will fill waters of the U.S. without first obtaining authorization under a nationwide or individual permit, depending on the amount of impacts.

• Section 404 of the CWA requires that all federal, state, and public entities obtain a permit from the U.S. Army Corps of Engineers (COE) before placing dredged or fill materials into waters of the U.S. as defined in 33 CFR Part 328 “Definition of Waters of the United States.”

• Section 401 of the CWA requires consultation and Water Quality Certification (WQC) with the state — Missouri Department of Natural Resources (MDNR).  State legislation has removed MDNR's authority to condition nationwide permits (NWP's) for MoDOT highway and bridge projects.  However, all activities that require individual permits and most requiring general permits will subsequently require WQCs.

MoDOT project concerns relating to waters of the U.S. (streams, wetlands and special aquatic sites) include potential stream impacts at linear crossings, filling of jurisdictional wetlands, stream channelization, and filling of designated special aquatic sites.  Other 404 related concerns that pertain to the design and/or construction of MoDOT projects include avoiding work in streams during the spawning periods, providing notification to the Corps when working in sensitive watersheds, and addressing fish and aquatic life passage issues when building multi-cell box culverts in select streams.  The handout “Streams, Wetlands and MoDOT” illustrates the resources, impacts, and mitigation that are involved in the 404 permit process.

If you are interested in owning a wetland site, please call 1-888 ASK MODOT.

 

Wetland Mitigation

Typically, if the COE issues a Nationwide Section 404 permit for a MoDOT project and the permanent impact (i.e., loss) to jurisdictional wetlands is greater than 0.1 acre, then wetland mitigation is required.  Mitigation for impacts greater than 0.1 acre often require additional right of way.  A wetland design needs to be incorporated into the project or arrangements made for a stand-alone project.  Where available, the district may have the option of using available credits in a Mitigation Bank for wetland mitigation.

Stream Mitigation

Stream mitigation is required when permanent impacts exceed 0.1 acre of fill in stream channels below the ordinary high water mark or if other stream impacts (i.e., channelization) exceed Nationwide Permit limits.  Mitigation can involve on-site design and/or utilization of the Stream Stewardship Trust Fund.  Stream mitigation may also be incorporated with threatened and endangered species habitat improvement such as the Indiana bat.  An example of Stream Mitigation is the Low-Water Crossing Retrofits.