Section 10 of the Rivers and Harbors Act (33 U.S.C. 401 et seq.) requires authorization from the U.S. Army Corps of Engineers for the construction of any structure in or over any navigable water of the United States, the excavation/dredging or deposition of material in these water or any obstruction or alteration in a "navigable water" (see below). Structure or work outside the limits defined for navigable waters of the U.S. require a Section 10 permit if the structure or work affects the course, location, condition, or capacity of the water body.
"Navigable waters" of the U.S. are those subject to the ebb and flow of the tide shoreward to the mean high water mark and/or presently used, or have been used in the past, or are susceptible for use to transport interstate or foreign commerce. The term includes coastal and inland waters, lakes, rivers and streams that are navigable, and the territorial seas.
Activities not requiring a Section 10 permit:
- Bridges or causeways - includes highway, railroad, and foot bridges as well as aqueducts, aerial tramways, conveyers, and overhead pipelines. Bridges do, however, require authorization for discharges or fill material under Clean Water Act (CWA) Section 404.
- Wharves and piers - must be located on water wholly within a single state and determined navigable, and not have an unacceptable impact on navigation.
- Hydropower facilities licensed by the Department of Energy. Discharges of dredged or fill material associated with these facilities still require a CWA Section 404 permit.
- Floating recreational facilities at reservoirs owned by the US Army Corps of Engineers.
- US Army Corps of Engineers civil works projects.
- CERCLA (Superfund) cleanup actions
Section 10 of the Rivers and Harbors Act and Section 404 of the Clean Water Act do overlap in some activities involving wetlands. Permits for activities regulated under both are processed simultaneously by the US Army Corps of Engineers.
Source: ceres.ca.gov