Flood Risk Management

Every year floods sweep through communities across theUnited States taking lives, destroying property, shutting

down businesses, harming the environment and causingmillions of dollars in damages. Nearly 94 million acres of landin the United States are at risk for flooding. It is impossible toprevent all floods, but it is possible to prevent some and tolimit the damage and risk from those that do occur.

One of the primary missions of the U.S. Army Corps ofEngineers is to support flood risk management activities ofcommunities in both urban and rural areas throughout theUnited States. To carry out this mission, the Corps operatesprojects that reduce flood risk and conducts emergencymanagement activities. At the direction of Congress, theCorps studies and implements flood risk managementmeasures. Over the years the Corps has significantly reducedthe impacts of floods by implementing measures such asdams, levees and floodplain management activities.

US Army Corps of Engineers US Army Corps of Engineers

Value to Individuals and Communities

The goal of the Corps Flood Risk Management mission isto reduce flood risk by saving lives and reducing property

damage in the event of floods and coastal storms. Bysupplying technical and geographical data, the Corps assistscommunities in developing responses to flood risks andhazards. The Corps also directly enhances public safety withstructural and non-structural measures and emergency actions.

Also, through effective planning, forecasting andpreparation, we can all help prevent floods or substantiallyreduce the loss of lives and property when they occur. Peoplewho live and work in the floodplain need to know about theflood hazard and the actions that they themselves can take toreduce property damage and to prevent the loss of life causedby flooding.

Specific Corps activities geared towards preparingindividuals and communities for potential floods include:

SSttrruuccttuurreess - The Corps is responsible for the constructionand operation of 383 major lake and reservoir projects,construction of over 8,500 miles of levees and dikes,construction of about 90 major shoreline protectionprojects along 240 miles of the nation’s 2,700 miles ofshoreline, building of hundreds of smaller local floodrisk reduction projects that have been turned over tonon-Federal authorities for operation and maintenance,and implementation of several non-structural projects toreduce susceptibility to flood damages.

AAddvvaannccee MMeeaassuurreess - When it appears that a flood isimminent in a specific area the Corps can take anumber of immediate steps to protect life and property,such as constructing temporary flow restrictionstructures and removing log debris blockages.

FFllooooddppllaaiinn MMaannaaggeemmeenntt SSeerrvviicceess ((FFPPMMSS)) PPrrooggrraamm - TheCorps provides information, technical assistance andplanning guidance (paid for by the FederalGovernment) to states and local communities to help

them address floodplain management issues. Typicalfocus areas are wetland assessment, dam safety/failure,flood damage reduction, floodplain management andcoastal zone management and protection.

FFeeddeerraall EEmmeerrggeennccyy MMaannaaggeemmeenntt AAggeennccyy ((FFEEMMAA))MMaappppiinngg - Over the past 30 years, the Corps hascompleted 3,000 studies for FEMA, mapping the floodpotential of various areas of the country. The Corps alsohas been instrumental in training private firms to carryout similar studies.

These measures are designed to reduce risks from floodhazards to people and their homes and businesses. Funding forflood and coastal storm damage reduction activities representsapproximately 30% of the Corps’ annual Civil Works budgetauthority.

Value of Flood Risk Management

Evolution of Flood Risk Management

Since the enactment of the Flood Control Act of 1917,the Corps has played a significant Federal role inmanaging flood risk nationwide. However, the Corpsʼmission and its implementation has evolved over time,moving from flood control to flood damage reductionand now, most recently, to flood risk management.Flood risk management is the process of identifying,evaluating, selecting, implementing and monitoringactions taken to mitigate levels of risk. Scientificallysound, cost-effective, integrated actions are taken toreduce risks. Social, cultural, ethical, environmental,political and legal considerations are accounted for in the process. There is an increased awareness within the Corps thatmore needs to be done to assess, manage andcommunicate flood risks. In 2006, the Corps establishedthe National Flood Risk Management Program in orderto advance the goals of flood risk identification,communication, response, and management servicesacross all levels of government in order to save livesand reduce property damage in the event of floods andcoastal storms.

Taking Small Steps to Address a Large Problem

Section 205 of the Flood Control Act of 1948 allows theCorps to implement small flood reduction projectswithout seeking separate Congressional approval.Through this program, the Federal government cancontribute up to $7 million dollars to address specificlocal flood problems in a fast-tracked program with afeasibility study prepared in partnership with a non-Federal sponsor. Both structural and nonstructuralalternatives can be considered for these projects. Suchworks are instrumental for efficiently preventing ormitigating flood damages, particularly when the risk islocalized. Recommendations are made in a feasibilityreport prepared in partnership with a local sponsor.Under these conventions the Corps can enact flood riskmanagement projects of the size and scope needed inmany communities and maintain collaboration with local entities.The Snoqualmie Flood Reduction Project is a Section205 proposal to lower flood depths in and around thecity of Snoqualmie, WA. Its three major elementsinclude: rock excavation along the right bank upstream

of the hydroelectricintake, earth excava-tion along the leftbank downstream ofthe SR 202 bridgeand removal of a partially-failed railroad bridge.

Value of Floodplains

Floodplains are complex systems that supportecological, social and economic services. Many of thefunctions and processes of floodplains cannot easily bequantified. Some examples of the diversity of benefits offloodplain areas are:• Natural flood reduction capabilities• Fish and wildlife habitat • Natural vegetation• Surface water quality and quantity• Ground water quality and quantity• Open space • Agricultural land • Recreation • Historic and archaeological preservation

Value to the Economy

US Army Corps of Engineers US Army Corps of Engineers

Value to the Economy

Some of the most valuable real estate in the nation is alsolocated in high risk areas that are prone to flooding. Many

industrial facilities are built near rivers and harbors for easyaccess to waterborne transportation. Coastal metropolitanzones are engines of growth for the economy. Coastalcommunities are highly desirable as residential locations andtourist destinations and offer many recreational activities butare vulnerable to coastal storm and flood damage.

The Corps Flood RiskManagement mission reduces therisk of flood damage to thesefacilities and homes as well as tovital infrastructure such as energygrids and transportation networks.

Since 1936 the Corps hascompleted over 400 major lake andreservoir projects, emplaced over8,500 miles of levees and dikes, andimplemented hundreds of smallerlocal flood damage reductionprojects.

These projects have prevented anestimated $706 billion in river andcoastal flood damage, most of thatwithin the last 25 years. Thecumulative cost for building and

maintaining these projects to date is more than $120 billion.That means for every dollar spent, approximately six dollars inpotential damages have been saved.

National flood damages averaged around $3.9 billion peryear in the 1980s and then nearly doubled from 1995through 2004. Total disaster assistance for both emergencyresponse operations and subsequent long-term recovery efforts

increased from an average of $444million during the 1980s to $3.75billion during the 1995-2004decade.

Typically, Corps flood riskmanagement projects are turnedover to states, local communities orthe private sector for ongoingoperation and maintenance, creatingjobs and revenue.

The Corps’ quick emergencyresponse to floods also helps theeconomy by preventing or reducingdamage to businesses. The Corps’ability to rapidly restore utilities,clear roads and rivers, and reinstateother vital services allows companiesto get back to business quickly,reducing flood related revenue losses.

Finally, through the Floodplain Management ServiceProgram the Corps responds to state and local requests forflood risk and assessment information. In a recent year thisservice responded to more than 44,000 requests forinformation. These data have helped protect property frompotential flood damage. Another effort, the Interagency LeveeTask Force, fostered rapid and effective recovery of floodplainmanagement systems affected by the Midwest floods of 2008.

Interagency Levee Task ForceMidwest Floods of 2008

In 2008, the Corps led the development of acollaborative regional approach to the long-termrestoration of flood management systems damaged bythe Midwest Floods of June 2008. By working with FEMA and other Federal, state andlocal agencies, the Corps assembled a regionalInteragency Levee Task Force (ILTF) to implement auniform approach across the region. Interagency LeveeWork Groups operated in state joint field offices toreview assistance requests from local entities, evaluatenonstructural alternatives and participate in the leveerestoration process. The ILTF worked to restore and protect residential,agricultural, commercial and industrial interests acrossthe region. Applicants received assistance with leveerestoration and repair from the task force.

Responding to Floods

Despite our best efforts, it is still impossible to entirelyprevent floods. When a flood does occur, Corpspersonnel are there to help. Often onsite in floodedareas within hours, the Corps works with other Federal,state and local agencies to provide a variety of vitalservices including:• Supplying drinkable water and emergency power;• Helping in search and rescue operations;• Clearing debris and blockages of critical water

intakes, sewer outflows and drainage channels;• Providing engineering services;• Emergency flood fighting;• Making emergency repairs to levees and other flood

control projects;• Restoring public services and facilities, like electrical

power or water supply systems;• Offering technical assistance, including structural

evaluations of buildings and damage assessments;• Building temporary shelters; and• Assisting with long-term recovery and reconstruction.

Flood Damage Reduction

13.4

21.2

2.8

21.9 23.1

15.7

22.5

24.0

9.2

42.3

0

5

10

15

20

25

30

35

40

45

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Fiscal Year

10-Year Average = 19.6

Bill

ions

of D

olla

rs

Flood Damages Prevented in the U.S.A. by the U.S. Army Corps of Engineers

Adjusted to 2000 Using Construction Cost Index EM 1110-2-1304

0

100

200

300

400

500

600

700

800

900

1928

1931

1934

1937

1940

1943

1946

1949

1952

1955

1958

1961

1964

1967

1970

1973

1976

1979

1982

1985

1988

1991

1994

1997

2000

2003

2006

Fiscal Year

Billi

ons

of D

olla

rs

Accumulative Benefits

Accumulative Expenditures

Annual Benefits

Flood Damage ReductionBENEFITS TO COST

$6.48 in Benefitsfor every

$1.00 Invested

Benefits of Federal Projects (Damages Prevented)Cumulative Corps Expenditures (Principle plus O&M)

Structural and Nonstructural Solutions

Structural measures have traditionally been used tocontrol flood waters. These solutions include levees,dikes, dams and reservoirs and they have successfullyprovided flood protection across the country.Nonstructural measures modify the ways that a flood-plain is used and can provide places for floodwaters togo while avoiding damage to communities. These solutions encompass measures such as expandingfloodways and natural habitats, creating flood waterstorage basins, enacting permanent evacuation offlood-prone areas, floodplain management initiativesand installing flood-warning systems.

The Corps flood risk management and emergency responseefforts help to limit the level of environmental damage

caused nationwide by floods. Environmental considerationsare an integral component of the planning process for allflood risk management projects the Corps undertakes.

For example, the Corps continues to encourage theimplementation of non-structural solutions that involvemodifying how floodplains are used or accommodatingcurrent uses to potential flood hazards.

A non-structural approach helps avoid changes to thefloodplains that might have a negative effect on theenvironment. Floodplains are complex natural systems thatprovide habitat for plants, fish, and wildlife and contribute tothe overall health of the environment. Significant changes tofloodplains can upset this delicate balance. As part of its flooddamage reduction efforts, the Corps has also instituted aprogram to manage sediment on coastal shores in an effort to protect property, infrastructure and valuable habitats.

Working Together

US Army Corps of Engineers US Army Corps of Engineers

Value to the Environment

In the United States, the responsibility for managing floodrisks is shared across the Federal, state and local levels of

government and the private sector. In the absence ofcontinuous collaboration conflicting policies, programs andinterests from multiple layers of government can work at crosspurposes and undermine efforts to improve flood riskmanagement nationwide.

In May 2006, the Corps established the National FloodRisk Management Program to provide support to the missionon integrating and synchronizing Corps flood riskmanagement activities, both internally and with counterpartactivities of the Department of Homeland Security, FederalEmergency Management Agency (FEMA), other Federalagencies, state organizations and regional and local agencies.

Specific goals of the Program include:• providing current and accurate floodplaininformation to the public and decision makers,

• identifying and assessing flood hazards posed byaging flood damage reduction infrastructure,

• improving public awareness and comprehension offlood hazards and risk,

• integrating flood damage and flood hazardreduction programs across Federal, state, and localagencies, and

• improving capabilities to collaboratively deliver andsustain flood damage reduction and flood hazardmitigation services to the nation.

Napa River Flood Protection ProjectNAPA, CALIFORNIA

The Napa River drainage basin comprises 426 squaremiles. The Flood Protection Project includes floodwalls,levees, excavated bypasses, bridge relocations andpumping stations, all of which will help to significantlyreduce the potential for flood damage. The innovativedesign approach, though, also allows for extensiveecosystem restoration in excavated areas.

Finding a Balance

When undertaking flood risk management studies, theCorps strives to balance and integrate societyʼs needsfor economic growth, public safety and environmentalquality. Trade-offs must be evaluated to determinewhich project provides the greatest benefit to the nation.Finding a balance that is acceptable to all stakeholdersand decision makers is one of the greatest challengesfaced by the Corps.

Johnson Creek ARLINGTON, TEXAS

The Corps has implemented a multi-objective flood riskmanagement and ecosystem restoration project onJohnson Creek in Arlington, Texas. Ecosystemrestoration alternatives include bank protection; naturalchannel design to restore, protect and expand theriparian corridor; aquatic habitat improvement; andconstruction of wetlands. Nonstructural measuresinclude acquisition and removal of structures while the structural measure is channel modification. Therecreation component of the project consists of trails,footbridges and picnic spots.

Silver Jackets

Through a collaborative effort with state and Federalagencies, the Silver Jackets program develops andsupports continuous interagency flood risk managementteams at the state level. Silver Jackets teams facilitate strategic life-cycleplanning to reduce flood risk and provide assistance in implementing state-identified high priority actions.Information and available resources are leveragedbetween agencies. Together, agencies solve issues and implement those solutions.The Silver Jackets program proposes establishing aninteragency team in each state with a representativefrom the Corps, Federal Emergency ManagementAgency (FEMA), the State National Flood InsuranceProgram (NFIP) coordination office, and the statehazard mitigation office. Other agency representativesmay vary based on team focus and activities. The intentof this program is not to duplicate existing interagencyteams, but to supplement already successful teams,strengthen existing relationships and establish newrelationships.

The Corps’ approach to flood risk management includesencouraging partners and stakeholders, including states and

affected citizens. Federal agencies collaborate to effectively andefficiently reduce flood risks and increase the nation’s awarenessof coastal and inland risks. These Federal partners include:

• Federal Emergency Management Agency

• Department of Housing and Urban Development

• National Oceanic and Atmospheric Administration

• Bureau of Reclamation

• Natural Resources Conservation Service

• United States Geological Survey

• Department of Homeland Security

Learn More

To learn more about the Corps emergency managementefforts visit www.CorpsResults.us

Tomorrow’s Challenges

Flood Risk Management reduces the risk of damage andloss of life due to flooding and coastal storms. However,

risk can never be completely eliminated. Substantial flooddamage still occurs, and lives are still at risk from flooding.

There are many reasons the nation faces flood risk.Challenges include:

• Many of the more than 20,000 communities in theUnited States, as well as rural floodplain areas, are stillsusceptible to flooding

• Aging infrastructure decreases reliability and increasesmaintenance costs

• New developments may influence run-offs and increaseflood risk

• Climate change may alter flooding patterns

• Federal and local flood risk policies sometimes areinconsistent

• Communities need to be more aware of risks anddevelop emergency management plans

• Current legislation only allows the Corps to study andbuild projects where willing sponsors exist

• Our understanding of hydrology is not complete; itimproves over time as we gain experience with each new event

• Recognition that residual risk is always present

The Corps is taking steps to address these challenges. Asthe Corps moves into the future, it must:

• Seek water resources solutions that better integrateeconomic, environmental and quality of life objectives

• Promote investment in flood and coastal riskmanagement solutions

• Support the formulation of regional and watershedapproaches to water resource problems

• Improve the efficiency and effectiveness of existingCorps water resource projects

• Address the operations and maintenance (O&M) backlog

Visit our Value to the Nation website: www.CorpsResults.us©2009 Produced by the U.S. Army Engineer Institute for Water Resources. To inquire about this brochure, please contact theIWR publications office at CEIWR.Publications@usace.army.mil. For the sources of information used in this brochure, visitwww.CorpsResults.us.

Sharing the Challenge