ABSTRACT
Since the 1970s, the federal government in the United States has been increasingly more active in regulating construction in wetlands. During this time many states have similarly developed programs to control development in wetlands. These regulations have necessitated the establishment of standardized procedures to identify and delineate wetlands. These methods utilize one or more types of wetland indicators, including hydrophytic vegetation, hydric soils, and other indicators of periodic wetness associated with wetlands. Several methods have been used for wetland identification: (1) vegetation-based methods, (2) soil-based methods, (3) three-parameter methods (using plants, soils, and other signs of wetland hydrology), and (4) the primary indicators method (relying on unique features to indicate wetlands). This article reviews wetland indicators and how they have been used in these methods to identify and delineate wetlands. Wetland mapping is also discussed. Recommendations are offered on how to improve identification of wetlands for regulatory purposes.
Since the 1960s and 1970s, wetlands have received increased attention in the United States due to the passage of wetland laws by numerous states and enactment of the Federal Clean Water Act and amendments. These laws and their accompanying regulations have placed certain restrictions on the use of wetlands on both private property and public lands. For the first time, it became important to establish the boundaries or limits of wetlands on a piece of ground to determine the areal extent of government jurisdiction. In effect, these laws created a type of land use zoning program where permitted activities and exempted activities were allowed, and other uses were not. The purpose of these laws was either to protect wetlands from destructive projects that could be constructed on less environmentally 114harmful sites or to regulate certain uses of wetlands that would adversely affect the quality of the nation’s waters. The former was largely the intent of state wetland laws, while the latter was a primary goal of the Federal Clean Water Act. Different approaches were developed to identify wetlands and their boundaries for these laws. The purpose of this chapter is to generally discuss these methods and to recommend some practical approaches for identifying and delineating wetlands. *
