Levee Fact Sheet

FACT SHEET

The NFIP and Levees
An Overview
There are thousands of miles of
levees in the United States that affect
millions of people. These structures,
usually earthen embankments, are
designed and constructed in
accordance with sound engineering
practices to contain, control, or
divert the flow of water so as to
provide protection from temporary
flooding. However, no levee provides
full protection.
The Federal Emergency Management
Agency (FEMA) manages the
National Flood Insurance Program
(NFIP), the cornerstone of the
Nation’s strategy for preparing
communities for flood disasters.
The NFIP was created to reduce
flood damages by identifying flood
risks, encouraging sound community
floodplain management practices,
and providing flood insurance to
lessen the financial impact of
flooding.
LEVEES: PROTECTION WITH
RISK
Levees are designed to provide a
specific level of protection. They can
be overtopped or fail in larger flood
events. Levees also decay over time.
They require regular maintenance and
periodic upgrades to retain their level
of protection. When levees do fail,
they fail catastrophically. The
damage may be more significant than
if the levee was not there. For all
these reasons, FEMA urges people to
understand their flood risk.

FLOOD HAZARD MAPS
IDENTIFY FLOOD RISKS

A COLLABORATIVE EFFORT

FEMA is updating flood hazard maps
called Flood Map Modernization.
These maps (also known as Flood
Insurance Rate Maps, or FIRMs)
indicate the high-risk zones (called
Special Flood Hazard Areas, or
SFHAs) with at least a one-percent
chance of flooding in a given year.
They also show the low-to- moderate
risk zones with a less than onepercent-annual-chance of flooding.

Ensuring the safety of life and

Identifying the risks behind levees is
an important element of Flood Map
Modernization. Levees are present in
approximately one quarter of the
counties being remapped. The maps
recognize some levees as providing
protection from the one-percentannual-chance flood, showing the
areas behind them as moderate risk
zones. However, before a levee can
be shown as providing that level of
protection, it must meet FEMA’s
accreditation criteria.

projects.

The levee owner must provide
documentation to indicate that the
levee meets the criteria. If it does, the
map will show the area behind the
levee as a moderate-risk zone. If it
does not, the map will show the area
as a high-risk area, or SFHA.

property in areas behind
levees is a collaborative effort.
FEMA establishes criteria for
levee accreditation and
identifies risk levels through
flood analysis and mapping

The U.S. Army Corps of
Engineers (USACE) is
responsible for building and
maintaining USACE-owned
levees, and for inspecting
those structures in the USACE
programs to determine their
level of maintenance.
States, communities, and
private levee owners assure
that the levees they own are
maintained to their design
criteria.

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Professional and technical
Because gathering the necessary
documentation can take time, FEMA
is allowing owners of eligible levees
two years to provide evidence of the
levee’s status. During that time, the
levee will be shown on the map as
provisionally accredited and the area
behind it will be shown as having a
moderate flood risk.
It is important to note that accrediting
a levee does not guarantee protection.
For all levees, the maps will carry a
warning that overtopping or failure of
levees, dikes, or other structures is
possible and that flood insurance
protection and adherence to
evacuation procedures are strongly
recommended.
REDUCING THE RISK BEHIND
LEVEES
Communities that join the NFIP are
required to adopt floodplain
management ordinances. These
ordinances are designed to minimize
damages to homes and businesses
located in SFHAs. In areas behind
levees that are mapped as SFHAs, the
NFIP requires all new or substantially
improved buildings to be constructed
to or above the elevation of the onepercent-annual- chance flood. In
areas behind levees that are mapped
as low-to-moderate risk areas, no
NFIP floodplain management
requirements apply. However,
appropriate precautions are still
encouraged as the risks for
overtopping or failure of the levee
remain.
FLOOD INSURANCE AND
LEVEES
Flooding is the Nation’s number one
natural disaster. Because
homeowners insurance does not
cover damage from floods, FEMA

offers federally backed flood
insurance through the NFIP. In many
low-to-moderate risk areas, singlefamily homes and businesses are
eligible for reduced-cost Preferred
Risk Policies (PRPs).
Areas behind levees that are credited
as protecting against the 1-percentannual-chance flood will be mapped
as areas of moderate risk and will not
be required to have insurance
coverage.
However, FEMA recommends flood
insurance for all properties behind
levees. Flood hazard maps carry a
warning that overtopping or failure of
the levee, dike, or other structure is
possible, and that flood insurance and
adherence to evacuation procedures
are strongly recommended.

associations, including floodplain
and stormwater management and
engineering groups, are
educating their members about
flood risks and appropriate
floodplain mitigation measures.
FOR MORE INFORMATION
Requirements for “Mapping of
Areas Protected by Levee
Systems” are outlined in Title 44
of the Code of Federal
Regulations Section 65.10.
Procedures for levee

WHAT ARE FEMA’S LEVEE
RESPONSIBILITIES?

accreditation can be found in:

FEMA is responsible for the
following:

FEMA’s Guidelines and

• Establishing appropriate risk zone
determinations and reflecting these
determinations on flood maps; and

Mapping Partners – Appendix H:

• Establishing mapping standards,
including minimum design, operation
and maintenance criteria that must be
met to have a levee recognized as
providing flood protection. FEMA
will only recognize on its flood maps
those levee systems that have met and
continue to meet these minimum
standards.
FEMA is not responsible for the
following:

Specifications for Flood Hazard
Guidance for Mapping of Areas
Protected by Levee Systems.”
FEMA Procedure Memorandum
No. 34, Interim Guidance for
Studies Including Levees
FEMA Procedure Memorandum
No. 43, Guidelines for Identifying
Provisionally Accredited Levees

• Designing, operating, certifying, or
maintaining levee systems;

Find these documents and more at

• Examining levees; and

www.fema.gov/plan/prevent/fhm/lv_fpm.shtm

• Determining how a structure or
system will perform in a flood event.

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