Through Section 404 of the Clean Water Act and many of its amendments the Secretary of the Army (acting through the Chief of Engineers) can issue permits for the discharge of dredged or fill material into the waters of the U.S., including wetlands. In other words, you can not fill in a wetland unless you have a permit for filling it in.

Wetlands although relatively easily to define are not always so easy to identify. Therefore, there are persons specially trained as wetland delineators that can identify an area as a wetland and determine the exact boundary between wetlands and uplands. As a quick review, wetlands must have 1) hydrophytic vegetation, 2) hydric soil, and 3) wetland hydrology. Depending on the season or the type of wetland these parameters may not always be evident. Therefore, a delineator must look for positive (+) indicators for all 3 of the parameters, except in limited instances.