The purpose of this layer is to provide an accurate representation of impervious surfaces in the City and County of Denver. This layer combines Stormwater Billing impervious surfaces with Planimetric impervious surfaces; allowing for a comprehensive, city-wide, impervious surface layer. This layer is a compilation of two independent sources of impervious surface data. The data is provided by both the City and County of Denver’s Wastewater Management Division-Customer Service (WMD-CS) and Kucera International Inc. The WMD-CS data represents areas digitized for all stormwater billing inspections after December 2002 and contains impervious surface delineations of each inspected property. These features are updated daily by WMD-CS field investigators and GIS personnel. The planimetric data, supplied by Kucera International Inc, defines the stereocompiled features of the DRCOG Denver Region Urbanized Project Area. The features were compiled from the Denver Regional Aerial Photography Project (DRAPP) 2016/2018/2020 Aerial Imagery Acquisition and Production. This 1"=100' scale imagery is comprised of 4-band RGBIR color orthoimagery with a GSD (Ground Sample Distance) of 0.5'. Imagery was collected with the Leica ADS40 and ADS80 digital sensors and processed with Leica XPro software. Imagery is projected in State Plane Coordinate System, Colorado central zone using the Lambert Conformal Conic map projection parameters. Horizontal and vertical datums are NAD83(11) and NAVD88(GEOID12A) respectively. The planimetric features are generally updated every two years.