- What problem is the National Committee on Levee Safety trying to address?
- If I don't live in New Orleans, should levee safety concern me?
- If levees pose such a risk to public safety, why hasn't something been done before?
- How can I keep my family and my home safe?
1. What problem is the National Committee on Levee Safety trying to address?
We are at a critical juncture in our nation's history — risks of loss of life, property damage, and damage to our
natural environment behind levees are increasing. The consequences of levee failure could be devastating. The
situation is the result of more than 100 years of inattention to, and in some cases neglect of, levee
infrastructure, combined with a growing population living in leveed areas and an economy and social fabric that
are in a particularly vulnerable state. Due to decades of inattention and underinvestment, there is not a full
understanding of where the risk exists and how significant the impacts of failure might be. Here is what we
- Much of our levee infrastructure is decades old and was built without the benefit of modern engineering.
- Levees protect other critical infrastructure, such as hospitals, roads, drinking and wastewater facilities, and
power generating facilities.
- Development continues to intensify behind levees, putting more people, property, and critical
infrastructure at risk.
- In many cases, the scale of development behind levees is outpacing the level of the levee's flood risk
- Much of the public remains unaware of their risk due to levee failure and overtopping and unaware of the
actions they could take to lessen that risk.
- Levee safety must be a shared responsibility requiring action by all levels of government — federal, state,
regional, and local — and the levee owners and operators. No single level of government, agency, or
organization can overcome these challenges alone.
In addition to reducing the risk of living and working in leveed areas, the National Committee on Levee Safety's
recommendations for a National Levee Safety Program are designed to reduce the overall costs of levee-related
flooding and make our national policies more aligned and rational. For example, by doing nothing, we continue
to pay exorbitant costs in the form of immediate disaster relief and post-disaster rebuilding. The National
Committee on Levee Safety (NCLS) estimated economic damages resulting from flood damages in leveed areas
to be between $5 and $10 billion annually, based on data from the U.S. Army Corps of Engineers, State of
California, and flood insurance data.
2. If I don't live in New Orleans, should levee safety concern me?
Levees are built in all 50 states, and can be found in 22% of counties nationwide. The nation's attention was refocused on the role of levees as critical infrastructure with the Mississippi River floods (1993 and 2008), California floods (1986 and 1997), and, of course, the tragedy of Hurricane Katrina (2005).
With economic damages stemming from Hurricane Katrina estimated to be more than $200 billion and a loss of life of more than 1,800 persons, the role of levees in providing for public safety and flood risk management was thrust back into the national spotlight. That experience reminded us of the following:
- What were thought to be good levees and flood walls can fail, and do so catastrophically.
- The complexities associated with communicating risk and evacuating large numbers of people are daunting.
- Organizing rescue and recovery efforts in a stressed, multijurisdictional context is challenging.
Louisiana and Mississippi are not unique in their reliance on levees in flood risk management. Chronic underinvestment of resources in maintaining or upgrading critical levees has been noted by many for decades. For example, the important role of, and reliance on, levees was noted in the Midwest floods of 1993. Since 1998, the American Society of Civil Engineers has published a "Report Card for the Nation's Infrastructure," and although they did not "grade" levees separately until their 2009 report card (when levees received a "D-"), dams and navigational infrastructure consistently rated poorly with Ds and D-minuses.
3. If levees pose such a risk to public safety, why hasn't something been done before?
There are many reasons why, individually and collectively, we have not acted to improve levee safety at a national level. Here are some factors:
- Part of our complacency is due to a misunderstanding of flood risk by decision makers and the general public. The National Flood Insurance Program uses the 1% annual chance flood (sometimes called the 100- year flood) as an actuarial standard. Homeowners living behind levees built to that standard are often exempted from the mandatory purchase requirement of flood insurance as a condition for a federally-
backed mortgage, so many communities have built their levees to that standard and residents feel safe.
The 1% annual chance level of flood protection is not a safety standard, however, and is frequently
misinterpreted. Many believe this protection means that a destructive flood will only occur on average
every 100 years. In reality, it means that there is a 1% chance every year that a flood of that magnitude
will occur, translating to a 26% chance of flooding during a typical 30-year mortgage.
- As a nation, we do not understand — or even know — our risks. Without a national inventory (pdf, 158 KB), assessment,
and inspection of all of the nation's levees, we do not know which ones protect the highest number of lives
or the most critical infrastructure, or if those levees are providing the levels of protection expected.
- There is no single agency (pdf, 194 KB) responsible for levee safety. Currently, responsibility for levee safety is dispersed
throughout all levels of government and quasi-governmental agencies such as levee boards.
- There are no national standards (pdf, 245 KB) for levee construction, inspection, or maintenance upon which to base our
4 4. How can I keep my family and my home safe?
Be informed. Know if you live, work, or go to school near or behind a levee. If you live near a major river or
other body of water, there is a good chance that a levee may be nearby. Here are some ways you can check to
see whether you live behind a levee:
- Contact a local government agency, such as your public works department or flood control district, to
find out about whether levees are nearby and if your home depends on them to reduce the risk of
- Check http://www.floodsmart.gov and take the "One Step Flood Risk Profile" quiz. In it, you enter your
address to learn if you live in an area at risk of flooding. If so, nearby levees may appear on the Flood
Insurance Rate Map created by the U.S. Federal Emergency Management Agency (FEMA) to show the
flood risk in your area. Follow the links on the site to FEMA's Map Service Center (msc.fema.gov ) to
download the map for your area. But be aware that levees are not always depicted on flood maps; your
local public works department or flood control district may have more accurate information.
Be educated. There is always some risk living or working behind a levee. It is important to assess that risk. No
levee provides full protection from flooding — even the best flood-control system or structure cannot completely
eliminate the risk of flooding. Levees are designed to provide a specific level of protection, and larger flood
events can cause them to be overtopped or fail. Levees also decay and deteriorate over time. Regular
maintenance and periodic upgrades are needed to ensure that they retain their level of protection and continue
to perform to their design. Maintenance can become a serious challenge as a levee system gets older. When
levees do fail, they fail catastrophically — the damage may be more significant than if the levee wasn't present.
Your flood risk associated with a levee depends on two major factors: (a) the hazard or probability that you will
be flooded, and (b) the potential loss of your property, the potential loss of your livelihood, or even the loss of
your life or the lives of your loved ones as a result of flooding. This may seem complicated but it's really
common sense. People with the highest risk: (a) live in floodprone areas with a high probability of being
flooded, and (b) have property that, if flooded, would be expensive or impossible to replace. Note that your risk
may change over time if risk factors change.
- Understand the potential depth of flooding and time it will take to evacuate your home, if necessary.
- Develop a personal emergency evacuation plan for yourself and your family.
- Keep important documents and duplicate records in a separate, safe place that is not prone to flooding.
- Purchase flood insurance — flood insurance could be an important element for safeguarding the financial
investment in your home, even if you are not shown as being in a high flood risk area.
- Learn who is responsible for notifying residents of flooding in your area so you know who to turn to for
- When under a flood warning, locate your pre-assembled emergency kit (which should include a weather
radio) and prepare other items to take with you in the event of an evacuation. Move valuable items
from basements and ground-floor levels to higher areas. Turn off electricity at your breaker or fuse box
and close your main gas valve. For fuel oil or propane tanks, turn off the fuel valve at the tank. Bring
outdoor possessions inside or secure them adequately. Place sandbags anywhere water may enter your
home. And, of course, if instructed to do so, leave immediately, avoiding areas of high or moving water.
Get involved. Encourage community officials to reduce the community's flood risk through a variety of
approaches, including: converting areas in floodprone areas into parks or greenways that can accommodate
flooding; remodeling or raising buildings to above floodwater levels; urging community homeowners to
purchase flood insurance; avoiding building structures, planting trees, or leaving debris on a levee; changing
zoning ordinances or building codes to limit development in floodplains; developing or refining flood warning
systems, emergency evacuation plans, and community flood preparedness; and providing technical and/or
financial assistance to property owners to protect against flooding.
(Adapted from So, You Live Behind a Levee!, American Society of Civil Engineers, 2009. Available online at
http://content.asce.org/files/pdf/SoYouLiveBehindLevee.pdf (pdf, 2.18 MB)