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Natural
History of the Anacostia Watershed: Land Use Land use in the Anacostia watershed follows the general pattern of other metropolitan areas, with the most dense development concentrated near the urban center; the average imperviousness of the entire watershed is 22.5%. With the exception of the National Park Service land adjacent to the tidal river, the largest areas of low density development (exhibiting 15% imperviousness) are found primarily in the northeastern and northwestern portions of the basin. These areas are comprised of low density residential development, forest and park lands, open water and wetlands, agriculture, and extraction. Residential development is the single largest land use in the Anacostia, comprising more than 43% of the watershed area. The "undeveloped" land-use category, which covers 30.7% of the watershed, is primarily forest and parks. The remaining forest and wetland cover in the watershed are discussed in more detail in subsequent sections. The industrial/manufacturing base in the watershed is confined to four percent of the land area. This land use is predominantly light industry and is concentrated in the Tidal Anacostia Area, and in the Hickey Run, Lower Beaverdam Creek, and Indian Creek subwatersheds. Extractive (sand and gravel mining) activities occur primarily in the Indian Creek subwatershed. Percent imperviousness in the individual subwatersheds range up to 37% and 48% in the highly industrialized Hickey Run subwatershed and Anacostia Northwest Bank, respectively. The lowest level of imperviousness is found in the Beaverdam Creek subwatershed (11%), which is owned predominantly by the U.S. Department of Agriculture and is operated as the Beltsville Agricultural Research Center (BARC). A moderate correlation (r2 = 0.61) exists between population density values and imperviousness in the subwatersheds of the Anacostia, with imperviousness increasing four to five percent for each additional 1,000 people per square mile, on average.
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