City of Tacoma GISThis polygon representation of built rooftop features is intended for quick mapping and impervious surface documentation. This data is static and may not represent current conditions and will be different than other sources such as basemaps. Each building has an associated elevation value. Omissions have been found throughout dataset, especially in industrial areas. Breaks between streets and driveways are not consistent. Objects coded as Unclassified include swimming pools, tennis courts, playgrounds, running tracks, etc. An Impervious Surface definition from the City of Tacoma: A hard surface area that either prevents or retards the entry of water into the soil mantle as under natural conditions prior to development. A hard surface area which causes water to run off the surface in greater quantities or at an increased rate of flow from the flow present under natural conditions prior to development. Common impervious surfaces include, but are not limited to, roof tops, walkways, patios, driveways, parking lots or storage areas, concrete or asphalt paving, gravel roads, packed earthen materials, and oiled, macadam or other surfaces which similarly impede the natural infiltration of stormwater. Open, uncovered retention/detention facilities shall not be considered as impervious surfaces for purposes of determining whether the thresholds for application of minimum requirements are exceeded. Open, uncovered retention/detention facilities shall be considered impervious surfaces for purposes of runoff modeling. Also available for download as CAD. From Tacoma Fire Service Area and Narrows Airport Planimetrics from July 2005 Ortho Photos.ArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/276a862530514c4e8e8daae65329d097_0engTacoma Open DataPublicBuilding Footprints 2005 (Tacoma) [Washington (State)--Tacoma]Web servicesWashington (State)--TacomaWashington (State)2005