Washington State Department of Transportation (WSDOT), Environmental Services Office (ESO)This is a view of the DrainageInlet featureclass created with the following query: NOT DrainageInletCategory = 6 AND LifeCycleCurrentStatus= 'Active' AND (WSDOTownership in ('Yes', 'Unknown') OR WSDOTownership IS NULL) AND (SWLocationVerified IS NULL OR SWLocationVerified = 'No') This feature class contains WSDOT's stormwater drainage inlets. A drainage inlet is a chamber or well allowing for the entry of surface runoff to a closed stormwater conveyance system. Inlet type is chosen based upon its hydraulic and interception capacity as well as depth of flow, grade, super-elevation, and placement.The majority of the data collected so far are within the Phase I and Phase II 2009 NPDES Municipal Stormwater Permit Areas. This feature class has eight subtypes: Catch Basin, Concrete Inlet, Drop Inlet, Dry Well, Grate Inlet, Manhole, Other, amd Unknown.ArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/5ab659466cb945a3bc89f1ebbe8a85e1_2engState of Washington Geospatial Open Data PortalPublicWSDOT - Stormwater Drainage Inlet - Office [Washington (State)]Web servicesWashington (State)Last Modified: 2026-01-06