Areas most-likely to be subjected to inundation by a 100-year flood, within the unicorporated areas of San Diego County, thus identified as 100-year floodplains. A 'floodplain' can be considered as any area that is suceptible to being inundated by water from any source. Mostly, this is the area adjacent to a river, creek, lake, stream, or other waterway that is subject to flooding when there is a significant run-off event and describing a large flat area where floods lose their speed and spread accross. As a result, floodplains can also known as areas having favorable agricultural potenial due to rich sediments deposited during water body slow-down.

This floodplain representation was originally created by County of San Diego, Department of Public Works, Flood Control Engineering, as a series hardcopy maps, based on 5-foot contour intervals at 200 feet per-inch (1:2400) scale and stored at the Survey Records counter of Dept. of Public Works. All of the areas depicted are subject to change due to development.

See original maps for the dates they were created.