Flood risk changes over time due to natural and man-made changes. The corresponding flood maps are revised periodically to reflect these changes and to improve map accuracy using better data and technology. The City and County of Denver works with UDFCD and FEMA to study flood risk and update flood maps.
Major Flood Map Revisions ("Physical Map Revision" or PMR)
A PMR is a FEMA process that is used for large changes to the Flood Insurance Rate Map (FIRM) and are commonly used to incorporate UDFCD Flood Hazard Area Delineation (FHAD) studies into the FEMA FIRMs.
Minor Flood Map Revisions (called "Letter of Map Change" or LOMC)