Wetlands Delineation

Wetland delineation is simply the act of establishing the boundary between wetlands and uplands (or non-wetlands). If a wetland exists on a property to be developed, the owner or developer will need to mark, or delineate, the boundaries of the wetland. Hiring an expert is the only way to guarantee that a proper delineation can be made. Draper Aden Associates has developed a complete water resources assessment and management team to deliver wetland delineation, permitting and mitigation services. Our experience with the regulatory agencies has made the task of confirming delineation even easier.

What is a wetland? According to the Environmental Protection Agency wetlands are areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season. The official definition from the Corps of Engineers (Federal Register 1982) and the EPA (Federal Register 1980) jointly define wetlands as: 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.

Why it delineation important? It is required by Clean Water Act Section 404 permit program. Section 404 requires a permit from the Corps or the Virginia Department of Environmental Quality for the discharge of dredged or fill material into the waters of the United States, including wetlands. This also includes those areas recognized as streams (i.e., waters of the U.S.).

Generally, activities requiring a permit include dredging, filling, or discharging any pollutant into or adjacent to surface waters, or otherwise altering the physical, chemical or biological properties of surface waters, excavating and draining wetlands, or conducting the following activities in a wetland:

New activities to cause draining that significantly alters/degrades existing wetland acreage or functions.
Filling or dumping.
Permanent flooding or impounding.
New activities that cause significant alteration or degradation of existing wetland acreage or functions.

The delineation process should produce:

Maps showing the size, location, shape, names of environmental resources.
types of wetlands (forested versus scrub/shrub versus emergent)
Data sheets listing soil, vegetation, and hydrology indicators.
Vicinity map that identifies the study area.
Narrative report describing the above information.