Evacuation in case of large scale flooding in The Netherlands 3 March 2010 Matthijs Kok, Bas Kolen HKV consultants

Topics Introduction Flood policy in The Netherlands Definitions of evacuation Evacuation scenarios Discussion about model assumptions Conclusion and questions

HKV - Water and Safety Private Company, 65 people Applied research and advise in: Risk analyses Emergency management GIS and IT Water systems 4 offices (Lelystad, Delft, Aken (GER), Jakarta (Asia) 15% of budget for R&D 15% target for projects outside The Netherlands Main client: Dutch Authorities (National en regional level)

Flood policy in The Netherlands 1953: “This may never happen again” Focus on prevention 1.International high safety level 2.Low probability, mass impact 3.Policy (since 2008 National Water Plan): Prevention (law) Spatial planning Emergency management (planning, forecasting)

Flood protection in The Netherlands 1. Coast and river 2. Canals 3. Rainfall

Flood protection in The Netherlands Frequency flood (river, sea) 1/1250 – 1/ year (protection act) Frequency threat is more 1/10 (alarm) 1/ year (evacuation – estimated) Early warning: Flood Forecasting Centers Bottom up alarm procedure River: 2-3 days Sea: 6h – 1 day New (more) mid term models: Top down procedure National Commission Flooding (LCO) Disaster Management Planning by National and regional planning (safety region, water board, etc)

Possible scenarios 1.Size (large, small) 2.Forecast (lead time: early, late) 3.Threatened area is sum all possible scenario’s, threatened area is related to window of forecast ‘Safety Standards’ Katwijk‘Safety Standards’ Rotterdam

Worst Credible Flood ‘upper limit’ 4300 square km 120 Mld Euro casualties movie

Organisation crisismanagement MPT/IPT NCCC RCC PCC MCC NCCNOCC The Hague Driebergen

Evacuation: the organization of and the movement to a (relatively) safe place in case of a threat Varying destination and moment of onset, types are: 1.Preventive evacuation: Movement before start of disaster to a place outside threatened area 2.Shelter (Horizontal and vertical evacuation): Movement before start of disaster to a shelter of safe haven inside threatened area 3.Shelter in place (only vertical evacuation): Move to upper floors 4.Acute evacuation: Movement after start of disaster before being exposed 5.Rescue:Movement supported by first responders after being exposed 6.Escape: Movement by self reliance after being exposed

Evacuation in The Netherlands Study ‘National Security, capability based planning’: 4 different strategies of evacuation 4 types of traffic management 1.Reference 2.Nearest exit 3.Optimal use of exits 4.Flow off areas Risk zoning in threatened area based on realistic forecasting (all possible floods)

National Security

Traffic Management / Route Choice

Model assumptions Evacuation of threatened area People at home at start and are self reliant +/- 10% not self supporting Communication (Evacuation routes are known, 20% will not ‘listen’) Behavior (traffic, departure) Enough resources (limitations are the next step) Outflow of area Road management (worst cases: nearest exit, reference, best cases: optimal use of exits and flow of (user defined)) Movie

Results: Bottle necks

Results: Extern bottle necks Bottle necks outside ‘evacuation zone’ when also considering outflow 48 hours after start MovieMovie: National concept evacuation (best case), preventive evacuation

Results after 33 hours % % % % % Advance national traffic management after 33 hours: - Evacuation population x % success in 33 hours (available time during Floodex)

Results More then 72 hours is needed for total preventive evacuation (strategy 1) for the Western Coast More then 24 hours is needed for only evacuating self supporting (strategy 4) for the Western Coast Preventive evacuation of entire coastal area in 48 hours (that includes 24 hour of severe storm) is not possiblePreventive evacuation Vertical evacuation, shelter in place (and support self reliance) is necessary to consider Advanced traffic management and strategies could work, but has to be implemented, prepared and communicated in time

Discussion Available Time Behavior of people Traffic management / Route choice Expected success of preventive evacuation (taking all possible scenarios into account)

Available time Extreme Wind T+..T+1T0T-1T-2T-3T-4T-5T Possible Dike Breach Detection and sense making Early Detection Late Detection -Uncertainty in forecasts (nature) -Uncertainty in interpretation of forecasts by decision makers and willingness to take action

Available time Coast River Time Probability for available time for evacuation (combination of forecasting and decision making)

Citizen response / self reliance ‘Citizen Response’ pertains to all actions taken by citizens (Helsloot & Ruitenberg): 1. preparing for disasters and major accidents 2. during and after disasters and major accidents 3. with the intent to help themselves or others to limit the effects of the disaster or major accident Conclusions: People make rational decisions on their interests, no panic or chaos Based on available information en knowledge Safety of family members is important Taking measures or preparation depends on perception of threat

Citizens response: Willingness to evacuate preventive or not Willingness to participate in evacuation is uncertain

Traffic Management / Route Choice What if all exits are used optimal (no ‘forced or informal’ connection region and route)?

Traffic Management / Route Choice -Reduction of necessary time -But model assumes: -Perfect behaviour (route choice far from logical for each driver) -Perfect implemented measures / decision making -In reality the best case if not realistic

Expected sucess of preventive evacuation in The Netherlands -Based on possible scenarios, probabilities in and event tree

Conclusion Flood policy has to deal with three layers (prevention, spatial planning and emergency management); standards has to be set for all The characteristics of a threat for flood and evacuation depends on space and time: Effectiveness of strategies of self reliance, and support of self reliance depends on actual circumstances A risk approach is needed for evacuation that takes uncertainty (threat, behaviour, decision making and environment) into account Capacity during emergency is limited, self reliance should be supported and facilitated Decision making is dealing with great consequences (economical impact because of the evacuation Thinking about evacuation is the start of a crisis (definition of a crisis ‘Rosental & Hart’) Authorities should prepare themselves, define standards, for all possible situations and during a crisis be able to select the most relevant; taking uncertainties into account and anticipate on consequences.

HKV CONSULTANTS Contact: Matthijs Kok +31 (0)320 – Bas Kolen +31 (0) Thank youk you Questions?

Authorities Self reliance public and organisation Threat (size and (lead) time) Physical environment Context of ‘society’ for flood preparedness