floods have been around for a long time -...
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Floods Have Been Around for a Long Time
Babylon Lived with a Flood Threat
Civilizations Have Grown Around Flood Infrastructure
Keeping Floods Away
Floods Were Part of Early North American History
And People Adapted
And Then Came Levees
• H&A• Levees• 1927
“Levees Only”
And More Recent US HistoryA Major Flood Occurred in 1927
The Solution: Federal Levees;
Floodways; Revetment;
Dredging; Dikes; Dams
•…flood control is a proper activity of the Federal Government -… the Federal Government should participate if the benefits to whomsoever they accrue are in excess of the estimated costs...
Congress Set the Policy Flood Control Act of 1928- Lower Mississippi ValleyFlood Control Act of 1936 - The Nation
Some Thought of Other Approaches
Gilbert White
Jim Goddard
John Kennedy
Non-Structural
And Legislated Programs• Disaster Relief• National Flood Insurance Program:
– 100 –year Standard– Local Land Use Control
• Unified National Program
Flood Damage Reduction
Mississippi River 1993
Grand forks natomas
Red River 1997
Photo by J Korn
2001 Mississippi River
Katrina 2005
2008 Midwest
Standards-Oriented Approach
Technical Flood Control/Action fully functional for
Flood Q design
Choice of Design Flood Q design(e.g.100 yr flood, SPF)
Assumption: No Risk of Failure for Flood Q < or = Q design
and Negligible for Q > Q design
from Pahlow, Dietrich, Nijssen, Hundecha, Klein, Gattke, Schumann,Kufeld, Reuter, Köngeter, Schüttrumpf, Hirschfeld and Petschow
Flood Losses
Now Add Stormwater!!
Levees and Other Structures Have Provided Protection to Millions of People and Saved Billions of Dollars
But Floodplain Development Including Levees Has Substantially Altered the Natural Environment (and Increased Risk)
Managing Flood Risk in the US: How did we get where we are and where do we go?
February 26, 2008 St Paul, Mn
Gerald E. Galloway, Jr., PE, PhDWater Policy Collaborative, University of Maryland
THE SPEAKER DOES NOT REPRESENT ANYONE OR ANY
AGENCY.
THE OPINIONS EXPRESSED ARE HIS OWN AND DO NOT
REFLECT, NECESSARILY, THE POSITIONS THE UNIVERSITY OF MARYLAND, THE ARMY CORPS
OF ENGINEERS OR ANYONE ELSE
Caution
Flood Management in US
Risk Based Management
Social, Goal Based Management
Standards Based Management
1% Chance Flood
NFIP1936 Flood Control Act
Risk, Uncertainty, Economics
Multi‐Hazard Management Homeland/ Security
Paradigm Shift
• Considering the evolution and trends, the approach to natural hazards requires a change of paradigm. One must shift from defensive action against hazards to management of the risk and living with floods
European Flood Directors
Reality• Flood protection is never
absolute and things can go wrong.
• Safety is available at a price - how much of the remaining risk has to be accepted by society?
European Flood Directors
The 21st CenturyPopulation ExplosionPressures for Development with Limited Land Use ControlClimate ChangeMinimal Resources
30
"Toto, I've a feeling we're not in Kansas anymore”
WHAT IS RISK?
RiskA Threat to That Which We Value
Vincent Covello
Risk (Flood)
Flood risk means the combination of the probability of a flood event and of the potential adverse consequences for human health, the environment, cultural heritage and economic activity associated with a flood event
EU DIRECTIVE 2007/60/EC
Managing Flood Risk
Risk-Oriented Approach
Risk of FailureHydrologicOperational
Affected Parties
100% Safety Cannot Be achieved by Technical
Means
Risk Management
from Pahlow, Dietrich, Nijssen, Hundecha, Klein, Gattke, Schumann,Kufeld, Reuter, Köngeter, Schüttrumpf, Hirschfeld and Petschow
Uncertainties
Unknowns
Determining Risk
Probability of Occurrence
HazardConsequences
Probability of Performance
SystemRISK ~
Probability of Flooding
Vulnerability
Minimization MitigationImpact
Insurance, education,, communication
Levees, dams, floodwalls, evacuation, floodproofing., codes
Managing Flood Risk
Probability of Conseqence
Risk Reduction
Tools
(Cumulative)
INITIAL RISK
Insurance
Land Use Controls, Building Codes
Levees, Floodwalls, Floodways
Education and Social Impediment Reduction
Policy Development
Living with Floods –Recognizing and Managing Risk
Modified from USACE
Geotechnical Hydrologic and Hydraulic Data and Models
Risk
RESIDUAL RISK
Challenges• How Calculate Risk?
• How Communicate Risk?
• How Prioritize Actions?
• How Decide What is Enough??
• Who Does What?
• Dealing with Watersheds and the Environment!
Calculating Risk
• The Hazard Risk– Stationarity: Hydrologic, Hydraulic, Land Use, Growth
– Uncertainty
• The ‘System” Risk– Structural Reliability: Dams, Levees, Other Structures
Fragility
Sayers 2002
Calculating Risk• The Hazard
– Stationarity: Hydrologic, HydraulicLand Use, Growth
– Uncertainty
• The ‘System”– Structural Reliability; Dams, Levees, Other Structures
– Non‐Structural: Floodproofing, Elevation, Zoning,
– System: Weakest Link
Calculating Risk• Consequence Mitigation (Probability of Being Effective)
–Measures: Insurance, Evacuation, Early Warning, Risk Communication, Education, etc
–Variables :
• Demographics: Age, Health, Knowledge, Language, Wealth,
• Leadership–National–State/Local
Risk Communication Challenges
• Who Communicates?– Variations in messaging among agencies/level of government
– Who is more effective
• How Communicate– Flood Maps: Historic; Inundation; Risk
– Message Channels – Social Networking
IPET 2009
Mapping
What Works?
Who Gets What Level of Support
ORFarms
Cities
Where is Risk the Greatest?
ALARP =As Low As Reasonably PracticableALARP = As Low As Reasonably Practicable.
What Is Tolerable Risk?
US: Tolerable<100 US deaths
World:Tolerable
.5000 deaths in Bangladesh
How Much Risk and To Whom?
How far should public officials in a democratic society attempt to influence individuals –go beyond informing them‐ concerning risks and risk reducing actions?
National Research Council Committee on Risk (1989)
Democracy?
Who Decides?
Public Policy NetherlandsNo Catastrophes!
The Royal Netherlands Embassy ‐Washington DC September 16, 2008
The Government of the Netherlands requested an independent Committee of State (the Delta Committee) to give its advice on flood protection and flood risk management in the Netherlands for the next century,..Large parts of the Netherlands lie below sea level and are even now experiencing the effects of climate change and sea level rise. The Netherlands delta is safe, but preserving this safety over the long term involves action now..
The Delta Committee has made ..recommendations to ‘future proof’ the Netherlands,
Before 2050: The present flood protection levels of all
diked areas must be improved by a factor of 10.
How Much Risk and To Whom?
Who Is Responsible for Flood Risk?
Risk Reduction
Tools
(Cumulative)
INITIAL RISK
Insurance
Land Use Controls, Building Codes
Levees, Floodwalls, Floodways
Education and Social Impediment Reduction
Policy Development
RESIDUAL RISK
Living with Floods –Recognizing and Managing Risk
Modified from USACE
Geotechnical Hydrologic and Hydraulic Data and Models
Risk
• Sharing Responsibility Is Collaboration• Collaboration Is Not Coordination• Collaboration Is Not Lurking
Coastal Restoration TeamNew Orleans, Louisiana
Integrated Watershed Planning and Environmental Enhancement
Integrated Water Resources Managementincludes
Flood Risk ManagementNavigation
Water QualityWater Quantity
Sediment ManagementEnvironmental Restoration
RecreationETC
Final Thoughts
• Flood risk management is complex; It is not going to be easy
• Risk management provides insights and assistance in resource prioritization
• We are struggling with some issues; need help
• Collaboration is essential• Policy is key
– If you don’t know where you are going, it is awfully hard to get there
Managing Flood Risk
What Must You Do?• Embrace this Change• Collaborate–hug a biologist• Keep yourself current – know what is
changing• Be persistent – you can do it• Educate others – in and out of your
field – Keep it simple!• Speak up when you should – remember
Challenger and Katrina• Be involved in Government and with
elected officials
You Make the Difference!
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