Demographics of Western South Dakota Wetlands and Basins

Abstract

Wetlands, whether natural or man-made in origin, are an important feature of the semi-arid landscape of western South Dakota. These wetlands have numerous social and economic values for both landowners and non-owners, as well as their values for fish and wildlife species. For this reason, accurate information about wetland abundance, characteristics, and distribution is important. These demographic summaries of wetland resources of western South Dakota were based on digital wetland data, as delineated by the U.S. Fish and Wildlife Service\u27s National Wetlands Inventory (NWI) office. Surface water covers approximately 257,006 ha or about 2.4% of the 10,810, 700 ha of western South Dakota. Surface water is divided into palustrine (50.2%), lacustrine (41.8%), and riverine (8.1 %) systems. There are 30% fewer hectares of NWI-delineated wetlands in western South Dakota than in eastern South Dakota. A total ofl72,867 basins exist in western South Dakota. Of these, 61,757 (35.7%) are classified as temporary, 50,447 (29.2%) as seasonal, 59,340 (34.3%) as semipermanent, and 1,323 (0.8%) as permanent basins. There are 86,927 created basins, which is 50.3% of the total number of basins. Of these, 72,562 are impounded basins, 14,054 are dugouts, and 311 were created by beaver (Castor canadensis) activity. There are fivefold fewer basins in western South Dakota than in eastern South Dakota. The wetlands and basins GIS created for this project and the resulting demographic summaries provide a temporal and spatial data baseline to which past and future changes in wetland demographics can be compared. Demographic summaries also will benefit resource managers in their efforts to conserve native species of flora and fauna and to understand the role that wetlands have in western South Dakota landscapes