The Corps and EPA have published a joint informational pamphlet discussing wetlands. It provides an overview of wetlands or 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. The Corps uses three characteristics of wetlands when making wetland determinations: vegetation, soil, and hydrology. Unless an area has been altered or is a rare natural situation, wetland indicators of all three characteristics must be present during some portion of the growing season for an area to be a wetland as outlined in the 1987 Corps of Engineers Wetland Delineation Manual and amended by the applicable Regional Supplement.
Regional Supplements are part of a nationwide effort to address regional wetland characteristics and improve the accuracy and efficiency of wetland-delineation procedures. Regional differences in climate, geology, soils, hydrology, plant and animal communities, and other factors are important to the identification and functioning of wetlands. These differences cannot be considered adequately in a single national manual. The intent of the supplement are to bring the 1987 Manual up to date with current knowledge and practice in the region and not to change the way wetlands are defined or identified. The procedures given in the 1987 Manual, in combination with wetland indicators designated on the applicable wetland data form and guidance provided in this supplement, can be used to identify wetlands for a number of purposes, including resource inventories, management plans, and regulatory programs. The determination that a wetland is subject to regulatory jurisdiction under Section 404 or Section 10 must be made independently of procedures described in the supplements.