taisuke watanabe, japan international cooperation agency - urban flood control: the case of the...

Toward Disaster & Climate Resilient, Toward Disaster & Climate Resilient, Sustainable CitiesSustainable Cities

─ Urban Flood Control and related tools── Urban Flood Control and related tools─

Taisuke WatanabeTaisuke WatanabeJapan International Cooperation AgencyJapan International Cooperation Agency

17 February 2015 @OECD Environet17 February 2015 @OECD EnvironetWatanabe.Taisuke@jica.gop.jpWatanabe.Taisuke@jica.gop.jp

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Presentation Outline- Low priority on disaster risk reduction (DRR) while increasing vulnerability →Mainstreaming DRR- Flood Control Measures in Manila →Gap bet. DRR and Climate Change- Tools Win-Win Land use Eco-DRR

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Increased vulnerability to Flood Risks in Urban Areas- Major Adaptation Challenge for Asian cities

Increased vulnerability to Flood Risks in Urban AreasHeavy Rainfall EventsRise in Groundwater LevelMultiple factors Related to Rapid Urbanization -More & faster water run-off-Habitation in high risk zones-Lack of measures

Adaptation measuresStructural MeasuresConstruction of Dikes, Improvement of Drainage, etc.Non-Structural Measures-Risk Mitigation Measures at Household/Community Levels-Early Warning and Evacuation System Appropriate City PlanningEnvironmental Management-Sewage System-Waste and Sanitary Management

Necessity of a ‘Long-term Resilient City Development Plan’

Necessity of a ‘Long-term Resilient City Development Plan’

There are many options for action.

Philippine National Climate Change Action Plan says;Adopt flood plain management and flood hazard reduction by establishing flood plain zones and new operating rules during flood periods as modular or incremental adaptation measure.

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Actions in National Climate Change Plan

Urban Flood Control in Manila

Structural measures - Mangahan Floodway - Pasig-Marikina River Channel Improvement & others - Observation and Operation System

Non-Structural measures - Forecasting & Early Warning

Capacity Building - National Gov and Local Gov - Training, Guidelines - Planning works

Manila: Pasig-Marikina River Basin

Mangahan Floodway

Phase &Ⅱ Ⅲ PhaseⅢ

PhaseⅣ

Rosario Weir

Pasig-Marikina River Channel Improvement

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・ O:Original PhaseIV Component ・ A:A+Hightenning Levee +Mangahan Floodway Improvement・ B:A+NRB+Additional Capacity

・ NRB +Additional Capacity

・ Dam+NRB・ Dam・ Dam+FCB

NRB: Natural Retarding BasinFCB : Flood Control Basin

Adaptation Measures for Climate ChangeStep Up Options of Adaptation Measures for Climate Change

・ Climate Change Adaptation Measures Options

• Preparing options based on existing plans and IPCC data

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New Dam Construction

Securing of NRB/FCB Volume

Underground Floodway

Underground Storage Facility（ Tunnel Storage）

Runoff Control Facilities

Estuary - MCGS MCGS-Sto.Nino

Dam flood control function Improvement

Sto.Nino

MF Capacity Improvement（ Securing of cross-sectional area or Laguna Lake level lowering Measure Upstream of Sto.Nino

NRB/FCB flood control function Improvement

Win-Win setting by incorporating DRR component

Implementing Projects with DRR elements in Various Sectors

Thailand： Flood Resilient Subway

Philippines: Typhoon Resistant HospitalThailand: Raised Road

Raised 1m for flood mitigation

– Road Raising for Flood Mitigation– Typhoon Resistant Hospital– School-cum-Evacuation Center– Flood Resilient Subway System

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Land Use: Setting River Boundary

Flood Risk Management Project for Cagayan de Oro River

Inundation Analysis/Inundation Risk

Assessment

Delineation of River Boundary/

Formulation of M/P

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JICA supported the Philippines on;•Assessment of local evacuation capacity •Inundation analysis and risk assessment •Updating flood master plan

JICA supported the Philippines on;•Assessment of local evacuation capacity •Inundation analysis and risk assessment •Updating flood master plan

Land Use: Reconstruction planning after Haiyan

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Political commitment on Typoon Yolanda (Haiyan): The government of Philippines sets “Build Back Better” as a basic concept for recovery and reconstruction by using the disaster as a trigger to realize disaster resilient societies.

Political commitment on Typoon Yolanda (Haiyan): The government of Philippines sets “Build Back Better” as a basic concept for recovery and reconstruction by using the disaster as a trigger to realize disaster resilient societies.

Concept for future Land Use Plan, “build back better”

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No build zone40m

Controlled zone

New Plan

Road

Rai

sed

Sea

wal

l×

Secon

dary

Pro

tect

ion

Road

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13

Sea wall

Secondary Protection Road

Controlled Zone

No Build Zone

Safe Zone

Project Scope was expanded for rehabilitation from Cyclone Nargis:Damage & recovery survey on the communitiesNew hazard map based on the satellite imagesCF extension & nursery centers rehabilitated with reinforcementRecovery survey of mangrove vegetation

Eco DRR Case : Myanmar- Cyclone Nargis 　　　

　　　　　　 Integrated Mangrove Rehabilitation and Management through Community Participation in the Ayeyawady Delta

Hazard Map

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Build Back Betterby Rehabilitation of Mangrove Forests

JICA Grant Aid Assistance (2012-2017)- Mangrove afforestation (1,154 ha) for enhancement of disaster reduction effects of mangrove ecosystem, validated / reaffirmed - including construction of a forest monitoring tower-cum-cyclone shelter / enhancement of participatory risk reduction training

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Mangrove Reforestation(Jul, 2009)

View of Mangrove Nursery Bed Area (Jul, 2010)

Thank you!

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