SANDAG's Land Layers are created for use in the Regional Growth Forecast to distribute projected growth for the San Diego region to suitable subareas in the region. These land layers include existing land use, planned land use, land ownership, constraints to development, land available for development, known site-specific developments, and lands available for redevelopment and infill. The land layers inventory is updated when new information is available. Many of these data sets are built from the San Diego Geographic Information Source (SanGIS) landbase. The land use information has been updated continuously since 2000 using aerial photography, the County Assessor Master Property Records file, and other ancillary information. The land use information was reviewed by each of the local jurisdictions and the County of San Diego to ensure its accuracy. Although this inventory contains more categorical detail and has better positional accuracy than previous land use inventories, users should be aware that this data may be too generalized for some local planning projects. Road right-of-way polygons and privately owned land are not part of this ownership layer.Adjacent parcel polygons with the same ownership have been aggregated (dissolved) into a single feature. MAPPING SOURCE: SANDAG, County Assessor's Master Property Records file, Cleveland National Forest, Bureau of Land Management (BLM), State Parks, other public agency contacts, SanGIS landbase (i.e. parcels) and local agency review.