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Water Supply in Dhaka
Mega City: A Strategic View
Professor M. Habibur Rahman, Ph D
Pro -Vice Chancellor
Bangladesh University of Engineering and Technology (BUET), Dhaka
M. Saiful Islam & Abdullah Al-Muyeed. Ph D
Department of Civil Engineering
Ahsanullah University of Science and Technology
Introduction Dhaka mega city is densely populated with more than
16.4 million in an area about 300 sq. km
The recent water supply requirement of 2100 MLD
The projected demand will be more than 4000 MLD in
the year 2020
The increasing trend of population growth will create
pressure on the existing water distribution system.
The Dhaka Water Supply and Sewerage Authority
(DWASA) cannot provide the recent requirement of
water
A combined water supply system comprising
accounted and unaccounted for water in mega city
Dhaka considering loss diminishing analysis, public
acceptance and awareness and alternate source of
water is the main focus.
The idea is to not only looking for alternative sources
but also to ensure effective and sustainable use of
the current sources that is best suited to meet city
water demand.
DWASA has total 4375348 Water Connection up to
December 2010
System loss in different year of DWASA
01020304050607080
1979 1990-
1991
1991-
1992
1992-
1993
1993-
1994
1995-
1996
2000 2003 2004-
05
2005-
2006
2006-
2007
2007-
2008
2008-
2009
Year
Sy
stem
lo
ss %
• AWWA Standards for Water System Audits
– 1991 “Unaccounted for Water”
– 2000 IWA/AWWA Water Balance • Provides consistent terminology
• Water Use Accounting nothing left “unaccounted for”
• Meaningful Assessment of Revenue and Non-Revenue Water
• System focus
Water Use Accounting
System
Input
Volume
(corrected
for known
errors)
Authorized
Consumption
Billed
Authorized
Consumption
Billed Metered Consumption
(including water exported) Revenue
Water
Billed Unmetered Consumption
Unbilled
Authorized
Consumption
Unbilled Metered Consumption
Non-
Revenue
Water
(NRW)
Unbilled Unmetered Consumption
Water Losses
Apparent
Losses
Unauthorized Consumption
Customer Metering Inaccuracies
Data Handling Errors
Real Losses
Leakage on Transmission and
Distribution Mains
Leakage and Overflows at Utility's
Storage Tanks
Leakage on Service Connections up
to point of Customer metering
AWWA Water Loss Accounting
Water Losses Non Revenue Water
Apparent Losses
• Meter Inaccuracies
• Data Handling Errors
• Unauthorized Consumption
Real Losses
• Leaks in Distribution
• Overflows at Storage Tank
Water
Treatment
Plant
Ground
water
Surface
Water
Authorized
Consumption Billed/Revenue Water
Billed Unmetered
• Estimates
• Flat rates
Billed Metered
• By Sector
• SF Residential
• MF Residential
• Commercial
• Institutional
Water
Treatment
Plant
Ground
water
Surface
Water
Authorized
Consumption Unbilled/Non Revenue Water
Unbilled Metered
• City Parks/Pools
• City Buildings
Unbilled Unmetered
• Fire Fighting
• Street Cleaning
• Line Flushing
Water
Treatment
Plant
Ground
water
Surface
Water
Water Demand Projections 2010 2015 2020 2025
Population in DWASA area 10,290,000 12,320,00
0
14,610,00
0 17,190,000
Served by DWASA (90%) 9,270,000 11,090,00
0
13,150,00
0 15,470,000
Slum population (15%) 1,540,000 1,850,000 2,190,000 2,580,000
Served by DWASA excl slum 7,730,000 9,240,000 10,960,00
0 12,890,000
Water Demand
- Residential l/c/d 140 130 120 110
- Slum l/c/d 35 40 45 50
-
Commercial/i
ndustrial
% 12% 15% 17% 20%
Total Ml/d 1,290 1,480 1,680 1,880
Unaccounted
for water % 35% 25% 25% 25%
Total water
demand Ml/d 1,980 1,970 2,240 2,510
Water Demand Projections (continued)
Water availability
Ground Water Ml/d 1,250 1,175 1,175 1,175
Saidabad SWTP I Ml/d 225 225 225 225 225
Saidabad SWTP II Ml/d 225 225 225 225 225
SWTP III (Khilkhet) Ml/d 500 500 500 500
SWTP IV (Padma) Ml/d 500 500
Total 1,700 2,125 2,125 2,625
Deficit/Surplus (280) 155 (115) 115
Source: Water Supply and Sanitation Sector Programme Support (WSSPS) Phase II funded by
Ministry of Foreign Affairs, Denmark
Analysis/results and implications for
policy and/or research
DWASA need to minimize loss to meet the demand
of water by existing systems
The UFW that is termed as system losses of DWASA
was as high as 75% in 1979.
The system losses were narrowed down to about
41.5% in 2008-2009.
Key Point-1
Strategic training of DWASA management is
required to minimize UAW, which is in many
developed countries is less than 10%, to mitigate
this issue.
Key Point-2
The alternate future water source is the surface water
But the major source of surface water like rivers and
lakes are in danger because of urbanization of the
huge population.
The possible options are Meghna and Padma rivers,
which are far from the city.
At least 150 MLD of water can be added to water
treatment plant of DWASA
The Government of Bangladesh planned to
implement a surface water treatment plant at Pagla
bringing water from Padma
Key Point-3
DWASA is also working on improving water supply
performance and creating new source through various
projects.
Dhaka Integrated Environment and Water Resources
Management Project,
Dhaka Water Supply and Sanitation Project,
Dhaka water Supply Development Project,
Emergency Water Supply System Expansion and
Rehabilitation Project,
Saidabad Water Treatment Plant (Phase-2) are the
major ones.
Key Point-3(Continued)
These projects are expected to increase water supply
by improving efficiency and creating alternating
sources.
However coordination of all this projects must be
emphasized and ensured.
The average rainfall in Dhaka city is around 2000 mm
per year.
Key Point-4
It is possible to store at least 30 MLD of water
by constructing storage tank on the roofs of the
buildings, which are readily available in Dhaka
city.
The people of the city must be encouraged to
store rainwater and to use this water especially as
a palatable purpose.
Key Point-5
There are also some industries, commercial places
where water is used only for cooling or washing
purposes or may be used in boilers that require
specific treatment for the purpose not all treatment as
performed by DWASA.
So it will be handy to have a secondary supply line in
industrial zones where preliminary treatment of water
will be done and in some cases specific treatment if
necessary.
The cost of this new network can be recovered from
the respected industries.
Key Point-5(Continued)
Using water efficient fixture.
Raising public awareness to minimize per capita water
demand.
Use of recovered water bathroom, wash basin for
flushing purposes, etc.
Considering only 5% recovery the total consumption
of 180 lpcd per person (future Dhaka Population 15
million) and, it is possible to add more than 100 MLD
to the distribution network.