The purpose of this article is to review the current state of wetland science as it pertains to impacts from urbanization, and to explore the possible management implications for local natural resource managers and land use planners who are the principal audience for this article. It is always difficult to generalize about wetlands because they are so diverse with respect to their hydrology, plant communities and landscape position. In a real sense, no two wetlands are similar in their quality or function. In addition, the nature of urbanization (also referred to as land development in this article) in the area draining to wetlands often differs greatly from site to site. Despite this variability, several consistent and recurring impacts have been observed in different wetlands around the country. At the outset, it is important to define the terminology that will be used throughout this article. Box 1 provides definitions for various terms used in this article and subsequent articles.