• City of Houston Impervious Area GeoDatabase

    The City of Houston 2012 Impervious Area GeoDatabase is an ArcGIS database that contains the 2012 Impervious Area layer used for to comply the drainage fee. an online version of the map is available at http://verify.rebuildhouston.org/prod/mydrain.htm

    The City uses GIS and Raster technology to get the impervious calculations. There are 3 Major pieces to calculating our Impervious Coverage Database:

    1. Orthorectified Color Infrared 3 band aerial imagery processed by ERDAS imagery software. Pixels either 1 for pervious or 0 for impervious. Greener aerials show up as pervious, browns and grays show up as impervious, even if it's barren land. Source: "Pixxures, Inc." via contract through H-GAC; licensed product cannot distribute to the public. Date of imagery flown -- January 2010

    2. Pictometry Building Foot print polygons overlaid onto of raster imagery from number 1 to add further impervious to the pixel count. New raster compiled.
      Source: Pictometry via inter local agreement via HCAD; licensed product cannot distribute to the public. Date of building footprints -- The 2010 Building Footprints were created from comparing 2006 imagery to Pre Ike 2008 imagery using aerial and oblique imagery. They are an older snapshot of the buildings and some have changed or are no longer there at all. (ghost buildings you refer to in videos)

    3. Parcel polygons overlaid on raster compiled from # 2. GIS layer used to associate an appraisal district account and address to the impervious vs. pervious land raster. This makes it an actual database now, whereas in steps 1 and 2 it is just a raster. We cannot gather any address specific data from a raster until you associate other GIS address and parcel data with it. Source: Harris, Fort Bend and Montgomery County Appraisal Districts Dates of parcels and appraisal district address and ownership various, but they are from recent tax year.

    Data and Resources

    Additional Info

    Field Value
    Author City of Houston, Public Works and Engineering
    Maintainer City of Houston, Public Works and Engineering
    Last Refresh Date 2012