Contrary to popular belief, wetlands are not always wet. And there may be a difference between what the Army Corps of Engineers and state and other regulatory agencies consider a wetland. This may lead to confusion by property owners, developers, consultants and permit applicants who receive conflicting information on whether or not their project requires a Department of the Army permit.
The Army Corps of Engineers defines wetlands as those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support a predominance of hydrophytic vegetation typically adapted for life in saturated soil conditions. All three characteristics must be present during some portion of the growing season for an area to be considered a wetland.
Wetlands such as swamps and marshes are obvious, but some wetlands are not easily recognized, often because they are dry during part of the year or don’t look visibly wet. Some of these wetland types include, but are not limited to, bottomland forests, pine savannahs, bogs and wet meadows.
Nearly 5,000 plant types that occur in the United States may commonly occur in wetlands. These include cattails, bulrushes, cordgrass, sawgrass, sphagnum moss, bald cypress, willows, bay trees, mangroves, sedges and rushes. Other indicators of plants growing in wet conditions include trees having shallow root systems, swollen trunks (for example, bald cypress and tupelo gum) or roots found growing from the plant stem or trunk above the soil surface.
There are approximately 2,000 named soils in the United States that may occur in wetlands. These soils, referred to as hydric soils, have characteristics that indicate limited oxygen in the soil due to periods of saturation during the growing season. Hydric soil indicators include a predominance of decomposed plant material (peats or mucks), a bluish gray or gray color below the surface, red streaks in the soil around plant roots, an odor similar to rotten eggs, or sandy soil with dark stains or streaks of organic material that, when rubbed between the fingers, leaves a dark stain on the fingers.
Wetland hydrology refers to the presence of water at or above the soil surface for a sufficient period of the year to significantly influence the plant types and soils that occur in the area. Besides standing or flowing water, evidence of the periodic presence of flooding or soil saturation may include waterlogged soil during the growing season, water marks on trees and drift lines, or small piles of debris oriented in the direction of water movement through an area.
Section 404 of the Clean Water Act requires anyone interested in depositing dredged or fill material into "waters of the United States, including wetlands," must receive authorization for such activities. The Army Corps of Engineers administers the Section 404 permitting process. Activities in wetlands for which permits may be required include, but are not limited to placement of fill material; ditching activities when the excavated material is sidecast; dam, levee and dike construction; mechanized land clearing; land leveling and most road construction. Not all wetlands fall under Army Corps of Engineers jurisdiction, and the Corps recommends early consultation to avoid unauthorized or non-compliant activity in wetlands.