“Flood Risk, I know it when I see it” …or not… Policy Considerations when Quantifying Flood Risk National Flood Risk Policy Summit July 13, 2009 Cambridge, MD Doug Plasencia, P.E., CFM

Do we have a common understanding?  RELIGION  FLOOD RISK

A Flood Risk Management strategy has broad implications  Introduces “risk continuum” vs. “at risk or not at risk”  Opens the door for considering a series of actions that increase or decrease risk  Should allow the ability to benchmark and monitor risk at various levels  Can and should be more than flood damage

A Robust Risk strategy includes  Property  Environment  Health and Safety  Recognition that risk perception is influenced by changing world views and cultural norms  Other

To be meaningful a risk strategy should  Benchmarks and monitors risk  Is predictive vs. reactive  Includes a focus on modifying risk behavior

Questions to resolve in quantifying risk  Which management outcomes?  Which method(s) to be used?  Is consistency between agencies required ?  Is consistency between agencies desirable?  Is risk a single number?  At what level(s) do we quantify and monitor?

How we quantify will influence reporting  Single Number “Dow Jones” like indicator?  Dash Board  Monitor multiple management objectives  Report Card  Perhaps most reactive technique

 3 rd Gilbert F. White Flood Policy Forum & Symposia  Symposia 1 - Quantifying Flood Risk (September 2009)  Symposia 2 - Communicating Flood Risk (November 2009)  Forum - Managing Flood Risk (March 2010)

To Quantify Risk we Should…  Consider our management outcomes  Evaluate risk quantification methods and strategies against specific outcomes  Adapt the method (s) in order to best support these management outcomes  Coordinate, collaborate, and strive for a reasonable degree of consistency in approach and outcomes  Recognize that risk management will evolve with changing needs

QUESTIONS AND DISCUSSION National Flood Risk Policy Summit July 13, 2009 Cambridge, MD Doug Plasencia, P.E., CFM

What is flood risk?  Single or discrete event- Probability of Flood Event X Damage or for 100-year event (P100*D100)  Perhaps allows consideration of residual risk  Probabilty Exceedance X damage or (PE100 X Damage)  (P100*D100)+(PE100*D100)  Continuous distribution – Sum of ((P1*D1) + (P10*D10) +….P500*D500))  Perhaps annualized  Other Measures of Risk  Non Monetized Impacts- (loss of life or casualties)?  Days of disruption?  Environmental Degradation?