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Water Resources Managementfor

Mega-Cities

OHGAKI, Shinichiro

Department of Urban Engineering, The University of TokyoJapan

Vice Chair, OECD/CSTP

Workshop on International Scientific and Technological Co-operation for Sustainable DevelopmentIn South Africa, OECD-SA, November 21-23, 2005

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The 13th Session of The United Nations Commission on Sustainable Development

(CSD-13)11-22 April, 2005,

at UN Headquarters in New York

The thematic issues were:to provide measures to facilitate and enhance implementation in themes of

water, sanitation and human settlements.

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(by courtesy of Prof.Gupta,Asian Institute of

Technology, Bangkok)

World Environment Day: June 5th 2005

UN Secretary- General Kofi Annan said, by 2030,more than 60% of the world’s population will live in cities. The growth poses huge problems, ranging fromclean water supplies to trash collection.

(Bangkok Post, June 6th, 2005)

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World mega-cities (over 5 million population)1950: only 8 cities in the

world

2015： 31 cities in Asia out of 58 cities

2020: 1 billion in Asia

©National Geographic, Nov. 2002

(By courtesy of Dr. Takizawa, The Univ. of Tokyo)

1950

2000

2015

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Detail Distributionof Urban Population (over 100,000)

(drawn by Dr. Ohta, Center for Sustainable Urban Regeneration,The Univ. of Tokyo)

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(Dr. Ohta, Center for Sustainable Urban Regeneration, The Univ. of Tokyo)

Distribution of Urban Population from Africa to Asia

10 million

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Urban and peri-urban areas are faced with many kind of threatsto water resources and water environment.

8(Source: Global Environment Outlook 3, UNEP, 2002)

Water problems with poverty in urban area

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● case study cities

Sri Lanka● ●

●

●

●

●

Ho Chi Minh

Bandung

Tianjin

Bangkok

Tokyo

by Freshwater ResourcesManagement Project,

Institute for Global Environment Sustainability, Japan

■ Singapore

■Singapore

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Anaerobic polluted river (in Colombo, Sri Lanka)

Heavily eutrophic river

(photo by Ohgaki, S., 2005 April)

11(by Mr.A.D. Sutadian)

Bandung, Indonesia

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Groundwater Problems (1) Quantity

Source: UNESCAP, 2002

Total Land Subsidence (1992-2000)

Groundwater Depletion- Water level drawdown- More difficulty in extracting

water

Land Subsidence- Damage to infrastructure- Flooding- Disturb/deteriorate drainage

systems

Bangkok, Thailand

(by courtesy of Dr.Babel, AIT)

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Layer 2:Phra Pradaeng Aquifer

Source: JICA 1995 Data collected in 1993

Groundwater Problems (2) QualityWater Quality Deterioration- saltwater intrusion

Saltwater of 2000 ppm intruded more than 80 km from the sea

(by courtesy of Dr.Babel, AIT)

Bangkok, Thailand

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15%

50%

23%

12%

Industrial Water UseAgricultural W ater UseDomestic W ater UseEcological W ater Use

Beneficial Use of GW (2002)

South part = salt water areas

50% of GW use is for agriculture

All GW use for agricultural is not counted = large different from

the actual use volume?

Groundwater Use and shortage of waterTianjin, China

(by courtesy of Dr. Xu He, Nankai Univ.)

15(Photo by Ohgaki, 2005 April)

TSUNAMI destroyed groundwater quality, also.

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Fresh Groundwater

Dug Well

Water Table

Pond, Paddy Field etc.

Saline Groundwater

Saline water Interface

Dry Soil Cover

TSUNAMI WAVES

Drawing by Dr. Gemunu HERATH and Shinichiro OHGAKI, (2005)Freshwater Resources Management Project,Institute for Global Environmental Strategies, Hayama, Japan

Original concept by Dr. Atula SENARATNE,Senior Lecturer in Geology, University of Peradeniya, and alsothe current Chairman of Water Resources Board, Sri Lanka

Saline Water Intrusion

AfterBefore

Sea Level

TSUNAMI

X

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Water in

Tokyo and Surrounding Urban Areaas a super mega city

(population : around 26 million)

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Water environment in Tokyo

Downtown, Sumidagawa River & Tokyo Bay

Water Resources: Ogouchi ReservoirSurburb

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100 km

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Yagisawa Dam

Fujiwara DamAimata Dam

Yatsuba Dam

Takizawa Dam

Naramata Dam

Tokura Dam

Kuriharakawa Dam

Sonohara DamKusaki Dam

Ogouchi Dam

Sagami Dam

Shiroyama Dam

Urayama Dam

Shimokubo Dam Edogawa riv.

Arakawa riv.

Tamagawa riv.

Tonegawa riv.

Nakagawa riv.

Sagamigawa riv.

Yamaguchi Res. Murayama Res.

Watarase Res.

Watarasegawa riv.

Arakawa Res.

Kasumigaura

Water ChannelsWater Treatment Plants

Water Network in Tokyo

Modified from the source: Bureau of Waterworks, TMG © S.Ishii, COE Project, Tokyo University

under construction

DamsIn operation

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0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

Population with water supply/sewerage in TokyoPo

pula

tion

(mill

ion)

Fiscal year

Total PopulationPopulation with water supplyPopulation with sewerage

© S.Ishii, COE Project, Tokyo UniversityCreated from the sources: Bureau of Waterworks, TMG; Keihin Office of River, MILT Japan; Bureau of General Affairs, TMG

Wor

ld W

ar II

22Copyright:Hajime Ishikawa@Tokyo Canal Project

Artery of water in Tokyo downtown

10 km

23Copyright:Hajime Ishikawa@Tokyo Canal Project

10 km

Vein of water in Tokyo downtown

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Combined Sewer Overflows Problem in Tokyo

Source: Bureau of Sewerage, Yokohama city & TMG

Source: Bureau of Sewerage, TMG

When the rain comes…

Combined type Separated type

797 CSO-outlets0 km 5 km 10 km

(by courtesy of Prof. Furumai, The Univ. of Tokyo)

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Source: Web site of Ministry of Land and Transport, Japan

Tama River flows through Densely Inhabited Area(22km from the river mouth)

26Sumidagawa riv.

Ochanomizu station

Nihonbashi

Kandagawa riv.

Picture source: Tokyo Canal Project

Picture source: Tokyo Canal Project

Picture source: Tokyo Canal Project

Rivers in Downtown of Tokyo

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Chofu intake gate

Yanagibashi bridge

Tamakawara bridge

Shingashi riv.

Shishigebashi bridge.

Tamagawa riv.

Kodairabashi bridge

Ryogoku bridge

Nakagawa riv.

Kasaikobashi bridge

Taishibashi bridge

71.0%

18.1%

32.3%

50.2%50.6%

95.9%

17.0%

35.3%

Modified from the source: Bureau of Sewerage, TMG

Sumidagawa riv.

Treated Effluents (%)

Large share of effluent from STPs in rivers

0 km 5 km 10 km 20 km

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Current issues associated with the water environment in urban area in Japan

-How to allocate a future water resource in watersheds

(rational beneficial use/reuse of water)-How to accommodate the multiple functions of

“water” in urban area(need of co-existence between human and ecosystems)

-How to maintain and upgrade the existing infrastructures

(e.g. aging sewerage systems, combined sewer overflow problem)

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For sustainable water resources and water environment of mega-cities

We are far from the ideal sustainable cities in both economically developing and developed regions.And the water is one of the most complicated social issues, but we have and are obtaining

our knowledge and toolson innovative science and technology,on new policy measures,on new implication methods, andon new system management.

For example,…..

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Some Technological Policies and Practicesfor

Water resources in mega-citiesin

Asia

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Rainwater for

toilet flushing and cooling waterIn

Tokyo

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National Sport Stadium

Tank capacity: 1,000 m3

For toilet flushing / cooling water

Daily use: 20.9 m3 (70% of total)

Tokyo Dome Stadium

Tank capacity: 1,000 m3

For toilet flushing

Daily use: 186.3 m3

Rainwater use

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Reclaimed wastewater from a sewage treatment plant

fortoilet flushing reuse

in a skyscrapers area in Tokyo

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Shinjuku Skyscrapers and Tokyo City Hall

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Shinjuku Area

Ochiai Sewage Treatment Plant

36Source: Bureau of Urban Development, TMG

Sinjuku wastewater reuse centre

Daily supply: 2,740 m3 (30% of total)

For toilet flushing only

Tank Capacity: 8,000 m3

37Source: Bureau of Urban Development, TMG

Category

Individual building

Group of buildings

Large area scale

Reclaimed wastewater reuse systems in operation in Tokyo (at March, 2002)

Number of system

293

170

97

43,809

20,167

17,062

Volume(m3 day-1)

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Reclaimed wastewater reuse for

Landscape regenerationin Tokyo

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Landscape regeneration using reclaimed wastewater

Nobidome yousui

Picture source: Bureau of Sewerage, TMG

Senkawa jyosui Tamagawa jyosui

Picture source: Mitaka Education Centre

Dry up

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Seawater Reclamation Experimental Facility

with UV radiation

at Tokyo Bay Seashore

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Tokyo Bay

Picture source: Bureau of the Environment, Tokyo Metropolitan Government:

ODAIBA

Tokyo Downtown

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Seashore and the Outlet of Reclaimed Seawaterin a Pilot Study (Started from July 2003)

（東京都環境局ＨＰ）Odaiba Seashore Park

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System on Reclamation of Seawater

Bio-membrane filtration

UV disinfection

Medium-pressure UV lamps

(1.9kW×12)

(Photo by MasagoJune 2003)

Discharge

Ariake WWTP

effluent

(5000m3/d)

Odaiba seashore

Ariake Canal

pumped up

(Oguma and Ohgaki,2003)

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Cascade system for

hand-washing water followed by

toilet-flushing

inan individual house in Tokyo

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Singapore (population = 4.2 million)

PUB, Singapore, has ensured a diversified and sustainable supply of water for Singapore with;

the Four National Taps

1. Local catchment water

2. Imported water (from Malaysia)

3. NEWater (reclaimed wastewater)

4. Desalinated water (from seawater)

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Marina Barrage （河口堰）

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Wastewater reuse in Tianjin, China

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Mobile Plant of Membrane Water Treatment Systemin Thailand

(By courtesy ofDr. Chavalit Ratanamskul,Chulalonkorn Univ., Bangkok)

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Patchwork on Environment in Asia-Pacific Region- Population density- Climate (Rainfall, Temperature, ………)- Sanitary condition- Measures against disasters (Tsunami, Earthquake, Flooding,….)

Pacific Ocean

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Mega-cities in economically developing regions in Asia-Pacific are experiencing mainly five major surges simultaneously:

-Increasing urban population,-Rapid economic growth and centralization,-Unprecedented technological development,-Social and cultural fragmentation, and -Surge of economic globalization

(Other regions like African cities would be in the same situation.)

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For future international co-operation on water issues;

Because of the patchwork-environment and the five surges in the current developing cities,

-We cannot discuss the water issues on the base of country-size but we should consider it as the specific areas.

-We should be careful that we do not misunderstand the real social issues in the specific area from the discussion on the country based data.

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For possible indicators of good practices in international science and technology co-operation (especially for water):

- Does the co-operation have a clear target area?

- Is the output from the co-operation based on the facts and evidence?

- Does the output from the co-operation clarify the priority of policy options?

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AcknowledgementsColleagues and friends

of-Center for Sustainable Urban Regeneration, The Univ. of Tokyo-Dept. of Urban Eng., The Univ. of Tokyo-Asian Institute of Technology, Bangkok-Churalongkon Univ., Thailand -Institute for Global Environment Strategies, Hayama, Japan

Ms. Kataoka, Y. , Dr. Hara, K., Dr. Gemunu HERATH-PUB, Singapore

-Tianjin, ChinaDr. Xu He and his team, Institute of Environmental Science and Engineering, Nankai University

-Bandung, IndonesiaDr. Setiawan Wangsaatmaja and his team West Java Environmental Protection Agency

-Bangkok, ThailandDr. Mukand Singh Babel and Ms. Niña Donna Sto. DomingoAsian Institute of Technologies

-Ho Chi Minh City, VietnamDr. Nguyen Phuoc Dan and his teamHo Chi Min City University of Technology

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Thank you