Municipal Separate Storm Sewer System Area

This layer depicts a generalized boundary of the District’s Municipal Separate Storm Sewer System (MS4) drainage areas. Each sewershed shows the general drainage area of a system of pipes and structures that carries only stormwater runoff that empty into natural or manmade surface waterways. This data is a requirement of the District's MS4 Permit. It is used for stormwater management and all aspects supporting efforts to comply with the Clean Water Act in the District. The dataset contains locations and attributes of the drainage areas of MS4 outfalls.本图层划定了本辖区市政分流制雨水管网系统（Municipal Separate Storm Sewer System, MS4）汇水区的广义边界。每个雨水汇水区（sewershed）均代表一套仅输送雨水径流、最终排入自然或人工地表水体的管道与构筑物系统的通用汇水范围。本数据集是辖区MS4许可的法定必备资料，可用于雨水管理及所有支撑本辖区落实《清洁水法》（Clean Water Act）相关要求的工作。该数据集包含MS4排放口汇水区的位置信息与属性特征。