Watersheds (File Geodatabase)

Montgomery County Department of Environmental Protection delineated 12 digit watersheds (recognized by State of MD) and tributaries. To show the County's delineated 12 digit watersheds (recognized by the State of MD) and subwatersheds for which stream conditions can be calculated. Layer is a union between the 12 digit watershed shapefile and the subwatershed shapefile. The polygons represent Maryland’s 12-digit scale watersheds. The delineation breaks the state up into 1,100+ watersheds. Thus, these watersheds are smaller in size than the 8-digit scale watersheds and generally represent drainage divides between 2nd order rivers/streams. These watersheds are identified via a 12-digit numeric code. Watersheds in this polygon file relate to TMDLs and WLAs in the applicable queries via a 12-digit watershed name identified in the location description, if applicable (i.e., if the TMDL/WLA is developed at a 12-digit watershed scale). Please direct any questions or comments concerning this map to Jeff White at [e-mail] or 410-537-3884.马里兰州蒙哥马利县环境保护局（Montgomery County Department of Environmental Protection）划定了经马里兰州政府认可的12位数字流域及其支流。本数据集旨在展示本县划定的、经马里兰州政府认可的12位数字流域，以及可计算溪流状况的子流域。该图层由12位数字流域形状文件（shapefile）与子流域形状文件（shapefile）合并生成。这些多边形要素代表马里兰州的12位精度流域。本次划定将全州划分为1100余个流域，因此此类流域的尺度小于8位精度流域，通常对应二级河流/溪流之间的分水线。此类流域通过12位数字代码进行唯一标识。本多边形要素文件中的流域，可通过位置描述中注明的12位流域名称，与相关查询中的总最大日负荷（TMDL，Total Maximum Daily Load）及废水负荷分配（WLA，Waste Load Allocation）建立关联，该关联适用于以12位流域尺度制定TMDL/WLA的场景。如有任何关于本地图的疑问或建议，请联系杰夫·怀特（Jeff White），联系方式为邮箱[e-mail]或电话410-537-3884。