WSDOT - Stormwater Ditch Type - BMPs

This is a view of the ditch featureclass created with the following query: WHERE NOT ( BMPTypeID = 24 OR BMPTypeID IS NULL OR BMPTypeID = 31) AND LifeCycleCurrentStatus= 'Active' AND (WSDOTownership in ('Yes', 'Unknown') OR WSDOTownership IS NULL) This feature class contains WSDOT’s stormwater ditches.A stormwater ditch is a long, narrow excavation dug in the earth for drainage, having a top width less than 10 feet at design flow. This can include various linear conveyances constructed of rock, gravel, earth, concrete, asphalt, or other material using forms, machinery, etc. It can also include a convergence in gradients of impervious surfaces (e.g., in a parking lot) designed to concentrate and convey stormwater.The majority of the data collected so far are within the Phase I and Phase II 2009 NPDES Municipal Stormwater Permit Areas.

本数据集为通过以下查询语句创建的沟渠要素类（feature class）视图：WHERE NOT ( BMPTypeID = 24 OR BMPTypeID IS NULL OR BMPTypeID = 31) AND LifeCycleCurrentStatus= 'Active' AND (WSDOTownership IN ('Yes', 'Unknown') OR WSDOTownership IS NULL)。该要素类包含WSDOT管辖的雨水沟渠。雨水沟渠指为实现排水目的，在地表开挖的狭长沟槽，其设计流量下的顶宽小于10英尺。此类沟渠涵盖各类通过模板、机械等工艺，由岩石、砾石、土体、混凝土、沥青或其他材料修筑的线性输水设施，同时也包括为汇聚、输送雨水而设计的不透水面坡度汇聚结构（例如停车场内的此类结构）。截至目前，已采集的绝大多数数据均位于2009年国家污染物排放消除系统（National Pollutant Discharge Elimination System, NPDES）市政雨水许可区域的第一阶段（Phase I）与第二阶段（Phase II）范围内。