Jakarta Floods

Hongjoo HahmWorld Bank

JanJaap BrinkmanDeltares - Delft Hydraulics

The World Bank

Jakarta flood management

• Part 1: The basics - Spatial Planning• Part 2: The flood of February 2007• Part 3: No-regret measures• Part 4: Tide and High tide floods• Part 5: Water specialist center, short-term actions• Part 6: Actions and financing structure

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Part 1

The basics: Spatial planning

“We live in a changing world”

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Total urban area % (java-bali spatial plan)2000 - 2025

Total urban area % (java-bali spatial plan)

2000 - 2025

It is really happeningIt is really happeningLanduse, JabodetabekLanduse, Jabodetabek19921992

20022002

Perubahan Penutup/Penggunaan Lahan di Daerah Puncak dan sekitarnyaMenggunakan Data Inderaja Landsat-TM

30-07-1992 17-09-2001U

G. Pangrango G. Pangrango

It is really happeningUrban area, G. Pangrango

1992 - 2001

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tugu

0

2

4

6

8

10

12

14

16

18

time (hours)

rainfall

(mm)

Land-use & Rainfall runoff

(Katulampa)

0

400

0

0.9

m3/s

m3/s

Fast runoffUrban

Slow runoffNon-Urban

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Part 2

Flood February 2007

Hydrology

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Daily rainfall Feb 2

Feb 1; 07:00 –

Feb 2; 07:00

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Daily rainfall Feb 4

Feb 3; 07:00 –

Feb 4; 07:00

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Inflow Ciliwung Febr 2007Katu Lampa - Manggarai

Banjir 31/01 - 06/02, 2007

0

100

200

300

400

500

600

700

800

1 12 23 34 45 56 67 78 89 100 111 122 133 144

m3

/s

Inflow 17

Inflow 16

Inflow 15

Inflow 14

Inflow 13

Inflow 12

Inflow 11

Inflow 10

Inflow 9

Inflow 8

Inflow 7

Inflow 6

Inflow 5

Inflow 4

Inflow 3

Inflow 2

Katu Lampa

1

23

5

67

8 9

10

1312

14 15

11

16

4

17

6

Katu Lampa

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Flood February 2007

Hydraulics & Flood extent

Unique

• “Complete upstream-downstream flood modelling framework now available for all major drainage including all 13 rivers”

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West Banjir canal

Part 3

No-regret ST Measures

Rehabilitation“Restore original-available

design capacity”-Dredging

-Dike improvement

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1 August 2007

C: River Embankment Rehabilitation

1. Confirmation of Scope of Works

West Banjir Canal – Longitudinal Section

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1 August 2007

C: River Embankment Rehabilitation

1. Confirmation of Scope of Works

Cengkareng Floodway – Longitudinal Section

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A: Urgent Maintenance Dredging

1. Scope of Works

National Importance

West banjir canaldesign

No-regret ST Measures

“East-Banjir Canal”

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• Stepwise approach:

A. Cipinang-Sunter-Buaran-Cakung(With increased Cipinang-Sunter capacity)

B. Finish EBC-NE stretchC. Optimize Manggarai gateD. Connect with Ciliwung

WBC EBC

Cakung

Sunter

Cipinang

Manggarai

Ciliwung

Increase capacity

Increase capacity

No-regret ST Measures

EBC-CAK-CIL-Manggarai Simulation 2007

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Existing – flood 2007

EBC-CAK-CIL-Manggarai

Part 4

Tidal analysisHigh Tide floods

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Animation of tide in South China Sea

Animation of tide in western Java Sea

Spring tide analysis

• Prediction based on analysed tidal constituents Tanjung Priok

• Only spring tides are plotted

• Upper plot: 18.6 year cycle caused by eliptical orbit moon

• Lower plot: semi-annual cycle presumably caused by interaction diurnal and semi-diurnal spring-neap cycle

Astronomic tide

Sea level anomaly

Flood event June 2007

• Increase in water level due to MSLA

• Spring tide (at semi-annual high)

flooding reported at June 14, ~10.00 pmFebruary 2007, not exceptional

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Future high spring tides

Next semi-annual high spring tide: October 29, November 26, December 24 -2007, January 21

Following semi-annual high spring tide: June 4, 2008

Month with the highest average MSLA!

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November 26, 2007

Subsidence

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1980

2003

Land-use change

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Pluit 1989, 2007, 2025(Positive view)

240 cm

Pasar Ikan cm

Nov 1989 Nov 2007 Nov 2025

Nov 26, 2007

190 cm Oct 29, 2007

140 cm

215220

225

subsidence

40-60 cm

40-60 cm

Climate changeSea level rise

subsidence

Critical level 2007

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240 cm

Pasar Ikan cm

Nov 1989 Nov 2007 Nov 2025

Nov 26, 2007

190 cm Oct 29, 2007

140 cm

215220

225

subsidence

40-60 cm

40-60 cm

Climate changeSea level rise

subsidence

2025:

80-100 cm increase

18.6 year cycle

Pluit 1989, 2007, 2025(Positive view)

Critical level 2007

Sea level Nov 26

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High tide floods 2007: “Signs of a sinking Jakarta”

Pluit 1989-2007 2007-2025 TotalSea level rise 4-6 cm 4-6 cm 8-12 cmSubsidence 40-60 cm 40-60 cm 80-120 cm

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Jadebotabek Water Resources

Management Study (JWRMS,1994)

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Part 5

“Strong knowledge base”

“Short-term action”

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Flood HazardMapping

• Still a lot of confusion!! – Who is right? – Who is going to solve this?– Who dares to make decision?

• One storey from specialists required!

• “Water knowledge center” for DKI - Jabodetabek

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Part 5

Actions and Financing mechanism

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ACTION PLAN

• Short Term:

– Dredging / East Banjir Canal / Manggarai Gate

– Stop Ground Water Extraction (industrial)– Early Warning System– Strict Building Codes

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ACTION PLAN

• Medium Term:

– Bulk Water Supply– Stop Ground Water Extraction (household)– Solid Waste Management– Low Income Housing / Slum Improvement

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ACTION PLAN

• Long Term:

– Water Quality– Water Retention Basin / Catchment Area /

Sea Defense– Land Use and Spatial Planning

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Jakarta Floods

Hongjoo HahmWorld Bank

JanJaap BrinkmanDeltares – Delft Hdraulics

Thank you!

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