Revised Definition of ‘Waters of the United States’; Conforming was published in the Federal Register on September 8, 2023. View the Corps announcement 8 September 2023 - EPA and the Army Issue Final Rule to Amend 2023 Rule and related announcements about Waters of the United States (WOTUS) on the the USACE Headquarters Regulatory Announcements page.


The U.S. Army Corps of Engineers is responsible for protecting many of the nation's aquatic environments including oceans, rivers, lakes, streams, ponds, and wetlands.

These areas are referred to by the Corps as waters of the United States. Work in, over or under waters of the United States may require a permit from the Corps. Permits, licenses, or similar authorizations may also be required by other federal, state, and local agencies.

Our headquarters website has additional jurisdictional determination information.


Permit Authorities

The Corps regulates activities impacting U.S. waters under three main laws:
Section 10 of the Rivers and Harbors Act of 1899 governs work impacting navigable waters.
Examples of activities requiring Section 10 permits:
• Construction or installation of piers, wharves, bulkheads, dolphins, marinas, ramps, floats, overhanging decks, buoys, boat lifts, jet ski lifts, intake structures, outfall pipes, and cable or • pipeline crossings
• Dredging and excavation.
• Overhead transmission lines, tunnels, or directional bore holes.
Section 14 of the Rivers and Harbors Act of 1899
33 USC 408 (commonly referred to as “Section 408”), authorizes the Secretary of the Army, on the recommendation of the Chief of Engineers of the US Army Corps of Engineers (USACE), to grant permission for the alteration or occupation or use of a USACE civil works project if the Secretary determines that the activity will not be injurious to the public interest and will not impair the usefulness of the project. For more information and to begin the application process for a Section 408 review, visit our Section 408 webpage.
Section 404 of the Clean Water Act regulates the placement of dredged or fill material into waters of the United States.
Examples of activities requiring Section 404 permits:
• Depositing fill, dredged, or excavated material.
• Grading or mechanized land clearing of wetlands.
• Ditch excavation activities in wetlands and associated discharge of dredged materials into wetlands.
• Fill for residential, commercial, or recreational developments.
• Construction of revetments, groins, breakwaters, beach enhancement, jetties, levees, dams, dikes, and weirs.
• Placement of riprap and road fills.
• Bank and stream channel stabilization projects.
Section 404 exemptions (33 CFR 323.4):
You do not generally need a permit under Section 404 for activities associated with normal farming, ranching, and forestry activities that are established and ongoing. Some of these activities include plowing, cultivating, minor drainage, and harvesting for the production of food, fiber and forest products. To find out whether specific activities are exempt, contact your local Corps office.
Section 103 of the Marine Protection, Research and Sanctuaries Act provides the authority to issue permits for transporting dredged material excavated from navigable waters of the United States to be dumped into ocean waters. This includes dredged material shipped by truck to a port site for ocean disposal.

Waters of the United States and geographic extent

Waters of the United States
The U.S. Army Corps of Engineers has jurisdiction over two broad categories of water: navigable waters of the United States and waters of the United States. More information.

Navigable waters of the United States
Navigable waters of the United States are regulated under Section 10 of the Rivers and Harbors Act. These are waters that are subject to the ebb and flow of the tide and/or are presently used, have been used in the past or could be used to transport interstate or foreign commerce. See a list of Oregon’s navigable riverways, harbors and bays (339kb PDF).

Waters of the United States
These waters are regulated under Section 404 of the Clean Water Act. These include navigable waters, lakes, ponds, small streams, some ditches, and adjacent wetlands. Waters of the United States include natural areas as well as areas that are man-made. If you are unclear about whether you have waters of the United States in your project area, please check with your local Corps Project Manager.

Geographic extent
The Corps’ regulatory jurisdiction extends to tidal waters of the United States, non-tidal waters of the United States, and territorial seas.

Tidal waters of the United States
Corps jurisdiction over tidal waters of the United States is outlined in Section 10 of the Rivers and Harbors Act and Section 404 of the Clean Water Act. Section 10 says the Corps’ jurisdiction in tidal waterways extends to the mean high water line. The mean high water line is the line on the shore established by the average of all high tides. It is established by survey based on available tidal data, preferably averaged over a period of 18.6 years because of the variations in tide. In the absence of such data, less precise methods to determine the mean high water mark are used, such as physical markings, lines of vegetation or comparison of the area in questions with an area having similar physical characteristics for which tidal data are readily available.

Section 404 says Corps jurisdiction in tidal waters extends to the high tide line. High tide line is the line of intersection of the land with the water’s surface at the maximum height reached by a rising tide. The high tide line may be determined, in the absence of actual data, by a line of oil or scum along shore objects, a more or less continuous deposit of fine shell or debris on the foreshore or berm, other physical markings or characteristics, vegetation lines, tidal gages, or other suitable means that delineate the general height reached by a rising tide. The line encompasses spring high tides and other high tides that occur with periodic frequency but does not include storm surges in which there is a departure from the normal or predicted reach of the tide due to the piling up of water against a coast by strong winds such as those accompanying a hurricane or other intense storm.

Non-tidal waters of the United States
In non-tidal waters of the United States, the Corps’ jurisdiction extends to the ordinary high water mark, a term used by the Corps in reference to the line on the shore of streams and lakes established by fluctuations of water. The physical characteristics of these fluctuations include a clear, natural line impressed on the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, the presence of litter and debris or other appropriate means that consider the characteristics of the surrounding areas. When adjacent wetlands are present, the Corps’ jurisdiction extends beyond the ordinary high water mark to the limit of the adjacent wetlands. When the water consists only of wetlands, the jurisdiction extends to the limit of the wetland boundary.

Territorial seas
The Corps’ jurisdiction in territorial seas begins at the shoreline and extends in a seaward direction a distance of three nautical miles. The Outer Continental Shelf Lands Act extends the jurisdiction of the Corps, under Section 10 of the Rivers and Harbors Act, to the seaward limit of the outer continental shelf for the construction of artificial islands, installations, and other devices on the seabed.

Recognizing wetlands

What is a wetland?
The U.S. Army Corps of Engineers (USACE) and the U.S. Environmental Protection Agency define wetlands as follows:

Those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas. Wetlands such as swamps and marshes are often obvious, but some wetlands are not easily recognized, often because they are dry during part of the year or "they just don't look very wet" from the roadside. Some of these wetland types include, but are not limited to, many bottomland forests, pocosins, pine savannahs, bogs, wet meadows, and wet tundra.

As a significant natural resource, wetlands serve important functions relating to fish and wildlife. Such functions include food chain production, habitat, nesting spawning, rearing and resting sites for aquatic and land species. They also provide protection of other areas from wave action and erosion; storage areas for storm and flood waters; natural recharge areas where ground and surface water are interconnected; and natural water filtration and purification functions.

Section 404 of the Clean Water Act requires that anyone proposing to deposit dredged or fill material into "waters of the United States, including wetlands," must receive authorization for such activities. USACE has been assigned responsibility for administering the Section 404 permitting process. If you intend to place dredged or fill material in a wetland or in an area that might be a wetland, contact the Portland District Regulatory Office for assistance in determining if a permit is required.