As part of its continuing strategy to update and enhance its flood insurance rate maps (FIRMs), the Federal Emergency Management Agency (FEMA) has developed mapping procedures for non-accredited levees.

FEMA began updating and modernizing its FIRMs in 2003 by moving from paper to a digital format and adjusting the boundaries of the 100-year floodplain — locations where there is a 1% chance of a flood occurring in any given year. 

In communities where the floodplain boundaries were expanded, the updated maps have been a concern for property owners who suddenly were required to purchase flood insurance. 

In some instances the change in the floodplain boundary was the outcome of a change in the status of a nearby levee from accredited to non-accredited.

A levee is a man-made structure, designed and constructed in accordance with sound engineering practices to contain, control or divert the flow of water to reduce the risk of temporary flooding.

FEMA’s previous policy on levees was cut and dried: either a levee was accredited or it was not.

The policy was changed when communities as well as members of Congress expressed their concerns that levees not meeting all of the criteria set forth by FEMA’s regulations can still reduce the risk of flooding, which should be considered as the maps are revised. 

FEMA’s new procedure for non-accredited levees does not address “levee-like structures,” which control and divert flood waters even though they have not been constructed exclusively for that purpose. 

These structures were considered in past mapping efforts, but will now have to be addressed in any reform legislation for the National Flood Insurance Program that Congress might consider in the coming year.

For more information on FEMA’s map modernization, email Matt Watkins at NAHB, or call him at 800-368-5242 x8327.