The Tahoe Regional Planning Agency (TRPA) limits the amount of impervious surface allowed on individual properties as a best management practice for protecting Lake Tahoe’s fame water clarity. The purpose of the regulation is to maximize the amount of undeveloped land available to infiltrate water and filter nutrients. TRPA requires that prior to applying for a permit to modify or expand the footprint of your residence or business structure, you must first determine if you have available land coverage. Land coverage is a man-made structure, improvement, or covering that prevents normal precipitation from directly reaching the surface of the land. Such structures, improvements or coverings could include roofs, decks, paved surfaces, walkways, driveways, parking lots, tennis courts and patios (hard coverage). Land coverage can also include compacted soil used for walking or driving on (soft coverage).
Spatial Informatics Group (SIG) was the first to use high-resolution drone imagery as the basis for preparing TRPA compliant site assessments for 16 different parcels owned by the Tahoe Keys Property Owners Association. The 3 cm/pixel photos were stitched together using Pix4D cloud based photogrammetry processing to create an orthorectified two-dimensional image for each parcel. Orthorectified images were brought into ArcGIS to ensure quality and correct for any horizontal shift. Ground features were digitized and measured from the georeferenced orthoimages and then classified based on 15 category land cover scheme. A Digital Elevation Model (DEM) derived from 2010 LiDAR data was used to generate one-foot contour lines.