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Managing Stormwater for Water Resource and Flood Control

Tan Tien SerAssistant Director

Catchment & Waterways DepartmentPublic Utilities Board, Singapore

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Managing the complete water cycle

Rain Sea

Indirect Potable

Use

Direct Non-

Potable Use

PUB is responsible for the sourcing, collection, purification and supply of drinking water, the treatment of used water and turning it

into NEWater, as well as drainage of stormwater

Desal

Water

NEWater

NEWater

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Integrating the Water Loop : Water for All

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Half of Singapore already serves as a water catchment

Catchment area will be increased to two-thirds by 2009 when new schemes are completed

1. Water from Local Catchment

Punggol Reservoir

Serangoon Reservoir

Marina Reservoir

Punggol Reservoir

Marina Reservoir

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INLAND RESERVOIRS

ESTUARINE RESERVOIRSPoyan/TengehTampines Pond B

STORM WATER COLLECTION POND

MacRitchie

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2. Imported Water from Johor

• Two water agreements with Johor, Malaysiao 1961 to 2011o 1962 to 2061

State of Johor, Malaysia

PUB pipelines carrying water from

Johor

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NEWater NEWater

Microfiltration

Ultra-VioletUltra-Violet

Treated Used Water

Reverse Osmosis

3. NEWater: Reclaimed Treated Used

Water

3. NEWater: Reclaimed Treated Used

Water

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NEWater: Fast Expanding

Kranji (9 mgd, Jan 2003) Seletar (5 mgd, 2004)

Bedok (7 mgd, Jan 2003)Ulu Pandan (32 mgd, Mar 2007)

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4. Desalinated Water To augment and diversify our water

resources

At 30 mgd (136, 000 m3/d ), it is one of the largest seawater RO plants

Opened by the Prime Minister on 13 Sep 05

Opening Ceremony

Desalination Works

Desalination Membranes

Chemical Storage Silos

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Flood control aspect of Singapore’s Urban Management

• High rainfall and dense urbanization in 1970s and 1980s Singapore led to frequent urban flooding

• Exacerbated by high tides (3+m tide range) and low lying coastal areas

• Singapore has had an ongoing effort since the later 1960s to build an effective storm drainage network

• This is fully integrated with the development of “new towns” which today house much of the population

• This has been very successful – with flood prone areas reduced to less than 100 hectares (and with limited flood depths)

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Flood Prone AreasFlood Prone Areas

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• annual rainfall of around 2350mm

• 2 main seasons dictated by monsoons

• northeast monsoon (Nov to Mar)

• southwest monsoon (May to Sep)

Physical conditions affecting drainage in SingaporePhysical conditions affecting drainage in Singapore

• island generally flat with pockets of low lying areas

• affected by high tides

• increased stormwater runoff from urbanisation

241.8

163.8

184.6 179.2171.1

163.0 159.3171.0176.2

194.0

253.9

285.3

Am

ou

nt

of

Ra

infa

ll (

mm

)

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Past major floods in SingaporePast major floods in SingaporeMaximum 24-hour rainfall (from 1931 to 2006)

0

100

200

300

400

500

600

Year

Am

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of

Ra

infa

ll (

mm

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Dec 1978Dec 19781,000 people affected7 people diedTide level = 3.2mTotal flooded area = 3178 ha

Dec 1969Dec 19693,000 people affected5 people diedTide level = 3.2mTotal flooded area = 2750 ha

Dec 1954Dec 195450,000 people affected5 people diedTide level = 3.2mTotal flooded area = 2540 ha

326

467

512

No Record

Dec 2006Dec 20068 nurseries, 29 families, 1 club house & 4 shophousesTide level = 3.0mTotal flooded area = 12 ha

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Am

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of

Ra

infa

ll (

mm

)

Year

1931

1940

1950

1960

1970

1980

1990

2000

2006

0

100

200

300

400

500

600

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3200 ha in the 1970’s Braddell Road, Dec 1978

Past Floods

Newton Circus, Dec 1969

Braddell Road, Dec 1978

Bideford Road, Dec 1969

Flood Photo 1954

Flood Photo 1954

Orchard Road, Dec 1954

Potong Pasir, Dec 1954

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Recent Floods

Beng Wan Road(4 Apr 05)

Bedok Ave 3 (14 Apr 06)

Jurong Port Road(17 Apr 06)

Pasir Ris Farmway 2(16 Oct 05)

Veerasamy Road(13 Apr 07)

Commonwealth Ave(18 Jan 07)

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Strategies to prevent and alleviate floodsStrategies to prevent and alleviate floods

(i) Drainage master planning and development control• maintain and update the drainage master plans in tandem

with land developments

• ensure that proper and adequate drainage facilities are provided to serve new developments

(ii) Drainage improvement projects• ensure that drains and canals are upgraded in time to

serve new developments

• remove constrictions in old drains/canals

(iii) Maintenance & enforcement programme

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Canal Outlet drain

Closed roadside drainOpen roadside drain

River

Types of drains/canalsTypes of drains/canals

820 ha safeguarded for drains and canals (excludes roadside drains within

road reserves)

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flood protection measures…flood protection measures…

Crest protection for MRT Clarke Quay Station

1.0m Crest

working with developing agencies…..working with developing agencies…..

Commonwealth Ave/Queensway Interchange

Higher platform level for waferfabrication plants

Jurong Island Complex

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Bukit Timah Phase 2A Flood AlleviationBukit Timah Phase 2A Flood Alleviation

Newton Circus , 13 May 1988

Bukit Timah Rd / Evans Rd,13 May 1988

Thomson Road , 3 Dec 1978

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1

2

1

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3

2

1

3

4

2

1

3 4

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Reservoir in the city – Marina Barrage Reservoir in the city – Marina Barrage

Marina Barrage – 3-in-1 project• Flood alleviation – to act as a tidal barrier to control floods

in the city

• Water supply – to be a freshwater reservoir

• Lifestyle attraction – vibrant waterfront with water based activities

VisionVision……

an exciting & vibrant an exciting & vibrant waterfrontwaterfront

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Marina Barrage … further reduce flood-prone areas

Low-lying areas in Chinatown, Jalan Besar, Rochor will be protected

Marina Barrage

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TNP Big Walk 2008 at Marina Barrage(2 Nov 08)

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Blue Map of Singapore

• 14 reservoirs • 32 major rivers • 7,000+km of waterways

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Active Beautiful Clean (ABC) Waters Programme

• Long-term initiative by PUB to transform our utilitarian concrete drains, canals and reservoirs into vibrant, aesthetically pleasing and clean flowing streams, rivers and lakes

“…Turn Singapore into a City of Gardens and Water” – PM Lee, ABC Waters Public Exhibition - Feb 2007

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ACTIVE Beautiful & Clean– Providing new community space– Bringing people closer to our waters

Active Beautiful Clean (ABC) Waters Programme

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Active BEAUTIFUL & Clean– Integrating reservoirs and waterways with the urban landscape

– Creating aesthetically pleasing lifestyle attractions

Active Beautiful Clean (ABC) Waters Programme

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Active Beautiful & CLEAN - Improving water quality

- Cultivating environmental responsibility among people

Active Beautiful Clean (ABC) Waters Programme

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The ABC Waters Master Plan

WESTERN

CENTRAL

EASTERN

• 28 projects over the next 5 years

• Over 100 projects in the long term

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Kolam Ayer ABC Waterfront

Before

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Bedok Reservoir

Car park

Seating Gallery

Floating Gallery -

decks and stage

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Bedok Reservoir ABC Waters Project

Features

– Landscaping

– Floating deck with performance stage and fishing deck

– Viewing galleries on reservoir banks

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Facilities @ Bedok Reservoir

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Sengkang Floating Island

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Sengkang Floating Island Artist’s Impressions

Today

A floating boardwalk camouflaged by plants connects the island and

the fruit park

A fixed bridge connecting floating island to the Anchorvale CC

The floating island helps to filter water while providing an

interesting transition from the community club to the fruit park

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Sengkang Floating Island Artist’s Impression

Fruit-themed pavilion creates a thematic link to the fruit park

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Thank You