While the City of Lancaster is the Floodplain Administrator, the Flood Insurance Risk Maps are developed and maintained by the Federal Emergency Management Agency (FEMA). The City of Lancaster has no jurisdiction to modify the maps or add or removed properties from the flood areas.
Flood Maps may be modified through a FEMA approval process. There are three basic processes.
This process is used when physical measures are implemented that changes the flood areas. Common changes would be implementation of flood control projects, channel or stream modifications or construction of levies.
LOMR changes are initiated by the City.
Letter of Map Amendment (LOMA)
This process is used to correct the map when a property is situated above the Base Flood Elevation due to existing site conditions.
Generally a LOMA will require an elevation survey of the property.
Letter of Map Revision Based on Fill (LOMR-F)
This process is used when a property owner physically alters the property by raising it above the Base Flood Elevation.
Generally a LOMR-F will be filed after a Development Permit and will require an elevation survey.