Flood Management Experiences in the United States

January26, 2001GWP-SAMTAC, Santiago Chile

by Jerome Delli Priscoli Ph.D.

Context • Federal System: state, local – resistance to Federal interference– limited coordination on water

• Property rights– individualism– free market, private ownership

• Resistance to land use planning– Flood management must integrate

land use

• Lingering culture of primary structural responses

• Tradition of helping the victims– reinforces discontinuity b/w

assistance vs.mitigation, prevention

History of Flood Plain Management US• 18th and early 20th century Local problem and

small scale structures• Mid 20th century Federal role and large structures• Later 20 the century back to more local and

movement to mix small and large and non structural

• Can track approaches in language e have used:– 1800s flood prevention– early 1900s flood control– mid 1900s flood reduction– latter 1900s flood plain management

What is Flood Plain Management?• …decision making process that aims to achieve

the wise use of the Nation’s flood plains.• ..a continuous process of making decisions about

whether and how flood plain lands and waters are to be used

• Multiple actors: owners, businesses, officials at all levels, farmers developers, etc.

• Simultaneously present,near future, and long term viability

• Balancing of relative costs and benefits

What is Wise Use? A Flood?• Wise Use…is any activity or set of activities that is compatible

with both the risks to the natural resources of flood plains and the risk to human resources (life and property)

• Defining a Flood..100 year flood, 1% annual chance flood or base flood, a flood of size that has a 1% chance of being equaled or exceeded in any given year.(Properties beyond 1% flood area still at risk)

Principles of Flood Plain Management in the US

• Major Federal interest but basic responsibility with sate and local governments

• See flood plains in context of total community, regional and national planning and management

• Flood loss reduction seen in larger context of flood plain management - not an objective in itself

• Resource management often focus on resource which may not be entirely in flood plain.

• Benefits and costs interrelated impacts• evaluation of alternative strategies

The Situation in the US• Over 150,000 square miles (94 million

acres) or 7% of country prone to floods• Almost 10 million households and $390

billion in property are at risk today• Rate of urban growth in flood plain twice

the rest of country• Average annual loss of life from floods

stable• Average annual flood losses rising• Loss of natural flood storage continues

Situation• Existing programs dampening but not solving

flooding problems in US• Damages incurred far less then damages prevented

by Corps projects alone. • Other programs and regulations are also

preventing and avoiding.• But damages have increased in real dollars and

disaster relief average $3 billion per year and uninsured losses are growing.

• Extreme weather conditions have made a difference (eg. Hurricane Floyd, Upper Miss ‘93, Grand Forks - some worst damage in US history)

Situation (con.)• Unprotected development in the 100 yr. plain and

continued development just outside the 100 yr.. Plain.

• Those deciding to live and do business in flood plain not paying proportionate costs of the decisions

• Grants and other post flood assistance reduce incentives to take preventative measures.

• 20,000 communities in flood plains, 90% participate in NFIP but less then 20% of occupants buy insurance.

Real Flood Damages 1903 - 1996 (Billions ‘95 $’s)

Flood Damages per Capita (‘95$’s)

Real Damages Prevented 1950 - 1996 (Billion ‘95 $’s)

Damages as % of GNP

Figure 5Benefits of Federal Projects (Damages Prevented)

Accumulative Corps Expenditures (Principle plus O&M)

Billions of Dollars (Adjusted to 1999 using Construction Cost Index)

$0

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Accumulative Benefits

Accumulative Expenditures

Annual Benefits

National Flood Damages Suffered

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History• Much of History written around the Lower Miss - Delta• By 1727 Nouvelle Orleans protected by 4 ft embankment• 1543 DeSoto noted:

– Indians raised mounds by hand and built high where they could

• From 1823 Federal role in water emerges -mostly navigation related with continual debate about flood control role with floods in mid 1800’s to 1917

• Debate in 1800s and early 1900s:– Ellet - mixed high levees, structure and outlets– Humphreys Corps of engineers -levees only– Humphreys wins out for 60 years until 1927 floods

• 1879 Miss river Commission

History (con.)• Flood Control Act 1917: lower Miss and

Sacramento river• Flood Control notion clashes with utilitarian use

last drop or it is wasted of progressive era• Flood storage and channel maintenance are

complex especially when linked to storage for supply and hydropower needs

History (con.)• Flood Control Act of 1928: 1927 floods greatest disaster

in US history 700,000 homeless, $250 million in losses– previous 200 yrs. locals spent $300 million in lower

Miss– In single 1928 act Congress authorizes $325 million -

the greatest % of budget for water projects ever in US!– Ellet view of structures comes back– Benefit cost ratio introduced– DOA to work upstream and the Corps down but no

coordination mechanism put in place– Between 1936 -1952 spent $11 billion for flood control

projects and storage: single and mutli- purpose– Idea was to build way out of the problem1954 Watershed and Flood Prevention Act SCS of DOA

History (con.)• 1940s to 1960’s Broadening views• As early as mid 1800s some realized the problem

was settlement and cultivation in the flood plain• Gilbert White, Harlan Barrows, U of Chicago,

Arthur Maass others develop alternative theory of flood management

• 1953 first first major test by TVA land use and flood control measures

• 1950’s, 60’s move for water resources coordination - WRC and River Basin Org.’s

• 1968 Flood Insurance Act

History (con.)• 1976 National Program for Flood Plain Management

submitted by the WRC to President• 1979 Revision of Unified National Program

– raise natural and beneficial values of flood plain

• 1986 Revision of Unified National Program– recommend federal support to state and locals– two major NSF studies

• 1993 Upper Miss flood: Galloway Report and 1994 Revisions to President - 3 major recommendations;– Full consideration to all possible alternatives, evacuation, warning,

proofing, natural and artificial storage – full weight to social economic and environmental values in

analysis– more non structural: to reduce vulnerability through use of flood

plain management activities and programs

Trends• Movements to coastal communities, adjacent to lakes and

rivers• Increased awareness in some parts of country to floods• Reduced ability to fund large capital measures those other

measures such as codes, regulation increasing• Rebalancing from structural to: local planning, regulations,

zoning, multipurpose management• NFIP a primary tool of management and increased

litigation over local government failure to endorse flood plain ordinances

• New awareness on natural functions of wetlands and internalization of EQ values

Trends• Improved GIS, mapping and science• Balance between public and private rights shifting

to: stronger pubic rights as pubic nuisances costs grow high Courts and legislatures evolving to reflect these concerns

• Less Federal emphasis on structural approaches and more state/local cost sharing in these

• Government payment for disaster assistance increasing

Institutional Coordination

• Private Sector• Local Communities• States• Federal Agencies

Resource Protection

Flood Management

in U.S.

DisasterAssistance

Red Cross

Farm Bi ll “Swa mpbuste r”

Federal E merge nc y ManagementAgency establi shed

C orps i nvolveme nt i nflood cont rol (Ri vers andHarbors Ac t 1824)

RESO URCEPROT ECT ION

Ameri can R ed C rossinvolveme nt i ndisa ste r re li ef

SC S authorize d to a ssist i nflood cont rol / conse rvat ionon smal l wa te rsheds

Associ ati on of St ate Fl oodplain Managers

St afford Disa ster Rel ie f Act

NATURALRESO URCE SMANAGEME NT

Nat ional Envi ronment alPolicy Act

C oa sta l B arrie r Re sources Act

USGS beginsflood studies

Soil C onservat ionServic e (SC S)est abli shed

USDA beginsrainfal l/ runoffme asure ments

FL OODCONTROL

B urea u ofR ecl ama ti onest abli shed

Fish and Wil dl ifeServic e e sta bl ished

Nat ional ParkServic eestabli shed

Water R esourc esPlanning Ac tUnif ied N ational P rogram f or

Managing F lood Losse s

Flood Disa ste r Prot ect ion Act

C orps Floodpl ain Manageme ntServic es Progra m

DISASTE RASSIST ANCE

1900

1970

1960

1980

1990

2000

1910

1950

1920

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1940

Key Events in the Progression of Floodplain Management

Eme rge nc y FloodC ontro l Funds Act

Flood Contro lAct of 1936

Fl ood ControlAct of 1917

Nat ional FloodIns urance Act

Exec ut ive Order 11988, F loodplain M anage ment

Unif ied N ati onal P rogram for Floodplai nManageme nt revise d

Unif ied N ational P rogram f or Floodpl ainManageme nt revise dWat er R esourc es De ve lopm ent Ac t

U.S. Fore st Servi ceconduct s flood controlrese arch in We st

FL OODPL AIN MANAGE MENT

Nat ional Ocea nic a nd AtmosphericAdminist rat ion establi she d

HUMANRESO URCE SMANAGEME NT

(Modified f rom A Unifi ed National P rogram for F loodplain Management, 1994)

Wat er R esourc es De ve lopm ent Ac tNat ional Weat her Servic e Mode rni zat ion

Federal Emergency Management AgencyUS Army Corps of EngineersSoil conservation ServiceNational Weather ServiceUS Geological SurveyHousing and Urban DevelopmentSmall Business AdministrationEnvironmental Protection AgencyDepartment of EnergyForest ServiceEconomic Development CommissionDepartment of TransportationPubic Health ServiceBureau of ReclamationUS Fish and Wildlife ServiceBureau of Indian AffairsNational Ocean ServiceNational Park Service

Large Number of Actors Involved:

•No WRC or formal coordinator

•Federal Agencies

• 1936 Flood Control Act:…non federal interests should (a) provide without

cost toe the US all lands, easements and rights of way necessary for the construction of the projects: (b) hold and save the US free from damages due to the construction works: (c) maintain and operate all the worked after the completion in accordance with regulations prescribed by Sec Army…

• Is a key to Institutional coordination

Cost Sharing: The Start 1936

Cost Sharing Today• Evolves in Legislation of ‘38, ‘41, ‘74, ‘86, ‘96• Non Feds pay 35% for Flood Control project• LERR & D needs identified: Value set and

credited to non Fed contribution.• Cash of 5% paid by non federal sponsor• Value of LERR & D and 5% cash added: if less

then 35% extra cash paid: if more then 50% non Fed is reimbursed.

• Non Feds pay 50% of separable navigation and recreational costs assigned to project

• Non Feds provide all LERRD’s and perform all related necessary relocations

Cost Sharing Evolution (con.)• WRDA ‘86:• Non Fed pays 5% of cost of project assigned to

flood control during construction• Non Feds provide all LERRD’s and perform all

related necessary relocations• Non Feds provide that portion of joint costs

assigned for FC• Total contribution on Non Feds will be equal to

25% of FC costs• Non Fed share shall not exceed 50% of FC of

project• Non Feds pay 50% of separable navigation and

recreational costs assigned to project

Evolution of Cost Sharing for Flood Management

• Many changes: Major changes in WRDA ‘86 and ‘96

• 1938 FCA: eliminates a-b-c requirements for flood control reservoir, channel improvements and LERR to include highway, railway, utility relocation

• 1941 FCA: a-b-c to again include channel projects• 19WRDA ‘74: amended (b) … shall not include

damages due to fault or negligence of the US or its contractors.

Cost Sharing (con.)• WRDA ‘96 • Changes percentage to 35%• LERR & D needs identified: Value set and

credited to non Fed contribution.• Cash contribution of 5% paid by non federal

sponsor• Value of LERR & D and 5% cash added: if

less then 35% extra cash paid: if more then 50% non Fed is reimbursed.

Strategies and Tools for Flood Plain Management

• Modify Human Susceptibility to Flood Damage and Disruption

• Modify the Impact of Flooding on Individual and the Community

• Modify Flooding• Preserve and Restore the Natural Resources

Regulations• Increasing Focus on Non Structural Measures:

– reduce or avoid flood damages without significant altering the nature or extent of flooding….

Modify Human Susceptibility to Flood Damage and Disruption

• Flood Plain Regulations (Codes and zoning)• Development and Redevelopment Policies• Disaster Preparedness• Disaster Assistance Flood Proofing, Flood

Forecasting and Warning System and Emergency plans– Problems linking evacuation and warning

• Preservation of Natural Resources

Preserve and Restore Natural Resources and Functions of Flood Plains

• Floodplain, wetland, Coastal Barrier regulations– Federal, State, Local, Reg’s, Zoning

• Development and Redevelopment Policies– land acquisition and open space, relocation,

restoration, habitat preservation, location of service utilities

• Information and Education• Tax adjustments• Administrative measures• Beach Nourishment and Dune Building.

Modify Flooding• Dams and Reservoirs• Dikes, Levees and Flood walls• Channel Alterations• High Flow Diversions• Land Treatment• On site Detention Shoreline protection• Special Grasses

Modify the Impact of flooding• Information and education• Flood Insurance• Tax Adjustments• Flood Emergency Measures• Post Flood Recovery

National Economic Development (NED) Categories of Goods and Services for

Public Water Investments1. Municipal and industrial water supply2. Agricultural floodwater erosion sediment reduction3. Agricultural drainage4. Agricultural irrigation5. Urban flood damage reduction6. Hydropower7. Inland navigation: Commercial & recreational8. Deep draft navigation9. Recreation10. Commercial fishing11. Coastal erosion, storm drainage reduction12. Environmental restoration

Key Rules for NFIP

• No Development in floodway• No residential living area below

1% flood level• No non-residential development

subject to damage by 1% flood• No rebuilding below 1% if

damage 50% or more of structures value

NFIP (con.)• Insurance industry participation in WYO program to:

– bring expertise, spread coverage, improve service

• Measures must meet minimum FEMA and include: zoning, subdivisions, building requirements, special purpose ordinances, outreach, education, others

• 1) Emergency Phase– Community applies– FEMA authorizes sale of insurance at reduced coverage– FEMA arranges study– FEMA provides FIRM– Community adopts new ordinances

• 2) Regular Phase– FEMA authorizes additional flood insurance– Community implements– FEMA arranges periodic assistance– Local officials request updated flood maps as needed

NFIP (con.)

•Replacement costs for residential single family and residentialcondos insured at 80% •Some increased costs of compliance paid

Policy, Planning and Analytic Approaches for Choosing Strategies and Tools

Analytic ApproachesBCA, Design StandardsHydrologic Analysis

Planning

Policy

Principles and Guidance forWater Resources Planners 1983

Uniform NFPM Prg. ’76,’79,’86,’94Exec Orders, Fed -State - Local Laws

Principles and Guidance (P & G): US Accounting System for Public Water Investments

• National Economic Development (NED)– beneficial and adverse effects on the national economy in

monetary terms

• Environmental Quality (EQ)– effects of plans on significant environmental resources and

ecological, cultural and esthetic attributes

• Regional Economic Development (RED)– distribution of regional economic activity from each plan in

terms of regional income and employment

• Other Social Effects (OSE)– effects on urban and community impacts, life, health, safety

factors; displacement, long term productivity; energy requirements and energy conservation

Some Project Level Policies• Without Project Condition• Flood Plain Management: avoid its dev. And focus

is on existing development• Use risk based analytical framework; expected

performance (no minimum) not levels of protection– can more small dams + more residual

• Reflect residual damages • Mitigation of induced flooding• Address minimum flow Evaluate EQ mitigation• No projects for single properties• Include steps of the NFIP: maps, etc.

Benefits Calculations• Urban

– Inundation Reduction Benefits– Intensification Benefits– Location Benefits– Damages: Physical damages, Income loss,

emergency costs• Agriculture

– Damage Reduction– Intensification– Reduction in damage costs; erosion,

sedimentation, inadequate water supply– Value of increased production of crops– Economic efficiency of increasing

production of crops

NOT CREATING NEW FLOODWAY DEVELOPMENTBenefits cannot exceed the increased flood damage potential in comparing existing activity to the intensified/ changed activity

Delineate Affected Area

Determine Flood plain

Determine existing flood damages

Estimate otherflood related costs

Estimate futureflood damages

Forecast activitiesin affected area

Estimate potential land use

Allocate land use

Collect market value data

Compute benefits

Urban Flood Damage Benefit Evaluation

Agricultural Benefit Evaluation Procedure

Identify land use - cropping pattern with and without plan

For land where croppingpattern does

not change with plan

For land where croppingpattern changes with plan

Determine damagereduction benefit

Select method for intensification benefits

Use farm budgetanalysis

Use land value analysis

Determine Total Crop Benefit

Analytical-Planning Impediments• BCA does not account

for EQ, Social and Distribution effects

• Lack of political process for consensus on EQ value

• Permanent evacuation costs high vs. structural measures

• Exclude benefit of reduction of primary flood damage for evacuation

• Exclude reduction in disaster recovery cost as benefit

• Does not include avoided damages as additional benefits

• Little guidance on location benefits

• Including interest overestimates costs

Analytical-Planning Impediments (con.)

• Project by project impedes systematic

• Institution resistance to change

• Non compliance with EO’s

• No coordination between buy out and FDP programs

• Poorest with most serious problems not participating

• Communities w/o vitality resist NSF

• Lower value of poor in flood plain provide less economic justification

Comparison Flood Depths vs. Location

Minn.

vs.

West Va.

Benefits of Non Structural Measures

Stage

Dam

age

Flood Warning PreparednessMethods for Quantifying Benefits

“Ad Hoc Method”

Warning shifts stage-damage curve downward

Flood Warning Preparedness “Day Curve”

0 6 12 18 24 30 36 42 48

0

5

10

15

20

25

30

35

40

Reduction in D

amages (%

)

Forecast Lead Time (in hours)

Barriers to Non Structural and Balance• Full accounting of EQ and non monetary social impacts on

NSF is difficult• Procedures used for BCR are based on certain assumptions

that limit non-structural • Emergency flood relief and recovery payments by

Government (FEMA) create incentives against non structural

• FPM not being pursued in comprehensive fashion at all levels of government

• Those who live and work in flood zones not paying proportional cost of the decisions

• National policy on disaster response and assistance not aligned to management: actually still creating incentives for locating in flood plain.

Barriers to NSFC• Analytical: Benefit Cost Analysis BCA

– Assess aggregate and blind to distribution– Perfect market conditions assumed– Dealing with non-monetized impacts– based on economic return thus may encourage investments in

high risk areas

• Policy: Principles and Guidance P & G and Policy– NED maximization rule biased against EQ -Social Accounts– Bias against broader non traditional benefits of NSF– System not set up to recognize least cost alternative which

may not be the best BCR– Issue for Treasury is cash flow and policy does focus on

minimizing tomorrow's losses

Overcoming Barriers: Policy Directions

• Sustainability• Nonstructural• Structural• Agricultural Policies• Coastal• Data and Technology• Risk• Repetitive Losses• Property Rights.

Sustainability

• Move toward likely future conditions to make risk analysis more realistic

• Including disaster resiliency in community planning: – FC measures flood resistant construction storm

water management– community zoning subdivision regulations

Increase Use of Non structural Measures

• Buyouts (1993 flooding)• Elevating buildings• Buffer zones and Levee set backs• Keep vacated land in pubic ownership• Seeking permanent authority for NSFC• National riparian zone policy • Natural storage capacity• Building codes - International building code

Increase Use of Non structural Measures

• New construction 1 - 3 feet of freeboard above base flood elevation

• Use confidence levels (90% -95%) for flood peak flows predictions

• No rise flood ways with no surface and velocity impacts

• Record waivers and disallow flood disaster assistance

Structural• Must integrate structures and NSFC measures in planning• Use water shed or basin wide approach• Estimate useful life of existing FC structures and dam

safety– 200 failures in last 10yrs– 9,200 categorized as high hazard– 35% not inspected since 1990– Rehab estimate = over $1 billion

• New structures should be built to protect beyond the 1% to the 0.2% chance flood - avoid catastrophic floods

• Include failure zones of structures on flood hazard maps

Structural (con.)• Tie zoning below dams to failure zones• Increase incentives for dam safety program

in states• Deal with small watershed aging dams

– over 10,000 in 2000 watersheds, 160 million acres

– one half over 30 years old• More technical assistance from Federal to

Locals on dams and FPM

Agriculture Policies• Crop losses often exceed urban losses

– over half of taxpayers damages • Examine prevalence of repeat areas of losses• Institute voluntary permanent Easements

programs like after 1993 floods– should deny subsidies and disaster

payments if refuse permanent easement purchase

• Buffer zones: eg. DOA - Conservation Reserve Program - 150++ feet

Agriculture (con.)• Levees; stop rebuilding where cost is greater then land

value - reduce Federal subsidy of 80% of costs• Construct levees so no impact on height of 1% flood• Several Crop insurance programs can encourage farmers to

plant in flood plains:– 1999 payments largest in US history at $28 billion– they guarantee 50% of average yield– 60%-65% of insured and uninsured losses paid in 1998– 25% - 35% premium discount for to farmers for buying up

coverage!

• Did not implement 1996 Flood Risk Reduction Program:– lump sum payments to offset Federal outlays on

frequently flooded land– pay 95% of 7 year market value – farmers could still use land way they wanted but no

loans or insurance eon that land..

Coastal • Existing polices foster rather then discourage construction

on coasts despite 1982 Barriers act• NFIP not working for coastal areas, need:

– integrate coastal areas into NFIP– surcharge on areas subject to erosion– setback requirements

• Shoreline erosion: shift from jetties, sea walls to beach nourishment– expensive and need better cost sharing– consider setbacks and acquisition strategies– increase pubic access to improved beaches

Data and Technology• No one entity has responsibility for collecting and storing

data about floods, defining floods, or damage!!• # of structures in flood hazard zone not known; need data

on repetitive loss structures• FEMA Improving methods for estimating flood damage• Stream gauge network is shrinking• New modeling that include unsteady flow conditions, levee

breaches, split flows and unstable land forms a debris flow being developed.

• Design manuals updated to include alternatives to structures and bioengineering.

Risk • Need to improve risk communication:

– 100 yr. becomes 1% or high risk flood– 500 yr. becomes 0.2% or moderate risk flood

• Movement to risk based may mean more structures and away from design to a minimum standard and more structures will be built and increased exposure.

• Structures at 1% flood risk has 25% chance of being flooded during its 30 yr. Mortgagee: a 1% chance that same structure will have a fire - yet almost all have fire insurance and less then 25% have flood insurance.

• Residual risk below structures: Maps need to keep failure zones after structures in place

Risk - Perceptions• Key to all is linking risk with behavior: active

choice/acceptance of risk versus passive being taken care of

• Engineers argued people felt more secure if see high levee or if see high earth dams versus stronger thin shell concrete

• Risk perception: People living on St. Andraes fault cannot understand how people can live in the Delta exposed to risk: Those in delta cannot understand those living on the fault line!

Flood Insurance: Repetitive Loss Problem• 2% of policies under NFIP accounted for 32% of

losses and received 38% of pay outs from the National insurance fund.

• 300 high loss repetitive communities, in 35 states, or 1.6% of the 18,700 communities in the NFIP; 31,574 structures are less then 1% of total insured but receive 29% of all NFIP loss payments

• Moving to actuarially based premiums or adjust according to use of mitigation

• Replacement cost better for coastal: Market value for riverine

Property Rights• Willing seller scenarios is basis

– key is partnership among levels of gov.and people (eg. Charles River in 1970s)

• Denial to rebuild as abridgment of rights– eligibility criteria exists

• Restriction on right to flood fight as abridgment– subject to state and community reg.’s– subject to liability of impacts on others

• National EQ programs as taking– eg. Wetland permitting

Conclusions• Flood Management is Complex• We have much experience but still trying• We have moved from fear to control to prevention

to management and working with the floods• Structures and non structures must work together.• Changing behavior is critical.• Movement to: Active acceptance of risk and

responsibility vs. passive paternalism • The civic culture and civic infrastructure come

together in flood management: a learning ground for building Democratic civic culture.

Lessons for GWP• Flood management important part of IWRM - optimal use

but brings complexity– links land to water: upstream to downstream– is a public good (eg.defense) thus offers additional

revenue sources for IWRM projects– help negotiating benefits vs. allocating flows

• Need to link post event reaction policy to anticipation, damage prevention and mitigation policies

• Hard to get benefits to poor if BC analysis is based on property values

• Critical issue is risk– communicating risk and reacting to warnings– active choosing risk versus passive acceptance links to

governance: building civic culture and democracy– From paternalism to informed consent