The primary indicators method—A practical approach to wetland recognition and delineation in the United States

Over the past 30 years, various methods have been developed to identify and delineate wetlands for regulatory purposes in the United States. This paper discusses major limitations of existing methods and offers an alternative method called the “primary indicators method.” This new method is based on using features (national and regional plant and soil characteristics) unique to wetlands for identifying wetlands and their boundaries. These primary indicators permit accurate wetland determinations and delineations in the absence of significant hydrologic modification because these features only develop in wetlands. Wetlands subject to significant drainage require an assessment of the current hydrology.