WHAT IS A STORM SURGE STILLWATER ELEVATION (SWEL)?
Storm Surge Stillwater Elevation (SWEL), is the flood level resulting from storm surge flooding during a projected 1-percent-annual-chance flood, or base flood. The SWEL does not include wind driven waves which ride on top of the SWEL. The SWELs for Louisiana are referenced to National Geodetic Vertical Datum of 1929.