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Water Woes of Mumbai
P.K. Charankar
Consulting EngineerRetired Deputy Municipal Commissioner
(Special Engineering)
Municipal Corporation of Greater Mumbai
2
Existing Water Supply Sources
Sr. No.
Name of the Source Year of Completion
Qty of Water Supply (MLD)
Total Qty of Water Supply
(MLD)(Cumulative)
1 Vihar Lake 1860 110 110
2 Tulsi Lake 1879 18 128
3 Tansa Lake 1892 to 1925 485 613
4 Modak sagar & Upper
Vaitarna
1957 1142 1755
6 Bhatsa (3 SCHEMES
TOGETHER)
1974 to 2007 1700 3455
Middle Vaitrna 2014 455 3910
Inclusive of 120MLD En-Route Supply
3
Water Supply: 3900 Mld
Major Water Treatment Plants:
Bhandup: Rated capacity 1910 Mld, working at 2100 Mld + 990 Newly added in 2014
Panjarapur: Rated capacity 1365 Mld, working at 1365 Mld
Vehar + Tulsi : Rated capacity 90 Mld
Master Balancing Reservoirs : 2 (Yewai & Bhandup)
Service Reservoirs : 26
Length of water mains : 4000 Kms
No. of Distribution Zones : 109
No. of Leak-detection Zones : 615
No. of daily operated valves : 800
Mumbai Water Supply Scenario
4
Sources of Water Supply For Mumbai
MIDDLE
VAITARNA
GARGAI
UPPER
VAITARNA
LOWER
VAITARNA
PINJAL
BHATSATANSA
Bhatsa release
Pise Pumping
1315 Mld to City
2435 Mld to City
670 Mld
2315 Mld
430 Mld
1765 Mld
VaiternaTansa
2020 Mld
Overview of Water Supply to
Mumbai
En route
120 Mld
Other sources
120 Mld
Raw water
Treated water
Net Flow to City: 3750 Mld
6
Length of water mains : 4000 KmsNo. of Distribution Zones : 109No. of Leak-detection Zones : 615No. of daily operated valves : 800Population : 13.3 millions
Mumbai Water Supply Scenario
Reservoirs
Distribution Mains
Service Mains
Consumer Connections
Source
Demand Supply Scenario
2001 2011 2021
12.2 m
14.4m16.7m
Source: Dr. Chitale Committee Report
2902
3033
4392
3798
38134243
Demand in Mld
Supply in Mld
Present Supply 3900 Mld
Simple Arithmetic
Total Supply = 3900 Mld
Estimated UFW = 30%
Net Available = 2730 Mld
Estimated Population = 20 Millions
Net availability/person = 136 litres/head/day
It is less than international standards but
Mumbai is not a water stressed area
10
Challenges of Mumbai’s Water Supply
Issues pertaining to Quantity of Water• Growing demand and problem of inequitable distribution owing to sub-
optimal pressure regulation.
Issues pertaining to Quality of Water• Contamination due to aging network and intermittent supply, peaking
during monsoon
Issues pertaining to hours of supply• Intermittent supply. Average duration of supply: 2-4 hrs.
Issues pertaining to “unaccounted for water”• Physical as well as revenue losses amounting to 20-25%
Issues pertaining to Cost of Operations and tariff
structure• Need to cover growing operational costs and generate surplus for
investments in water supply infrastructure through efficiency
enhancement measures and timely and periodic revision of user
charges
11
Action Plan For Improvement in
Water Sector
Source Augmentation
Better Supply-side
Management
Better Demand-side
Management
13
Long Term Plan For Source Augmentation
In the year 1993, the Govt. of Maharashtra appointed an expert committee under the
chairmanship of Dr M A Chitale (Ex-Secretary, Irrigation Dept) for advice on the long term
planning for augmentation of water supply to Mumbai. The committee recommended
development of following sources in phases
The GoM has accepted the Dr. Chitale Committee recommendations and has
approved allotment of these sources. The MCGM has therefore taken up the Middle
Vaitarna Project as an immediate additional source of water supply. The same was
completed in 2012. It is expected that the supply will be available from October
2014.
Simultaneously feasibility of Gargai and Pinjal Projects is currently being studied
Sr. Source Basin Yield
No. [MLD]
1 Middle Vaitarna Vaitarna 455
2 Gargai Vaitarna 455
3 Pinjal Vaitarna 865
4 Kalu Ulhas 590
IV MUMBAI (MIDDLE VAITERNA) WATER
SUPPLY PROJECT
Completed in 2012
Tunnel for Conveyance completed in 2014
Water Availability 455 Mld
Challenges in Source Augmentation
All new sources are situated in
Environmentally sensitive areas. For
Example: Gargai is located in Wildlife
Sanctuary
Forest land will have to deforested.
Land acquisition of revenue land is costly.
Rehabilitation of Project Affected People is a
great challenge for executing agency
Challenges on Supply Side
Management
Leakages in transmission and distribution
network
Contamination
Unequitable distribution
Reduction in NRW -Physical leakage
-Thefts
- Incorrect metering
18
Supply Side initiatives: Distribution
NetworkComprehensive Water Supply Distribution Improvement Programme
1. Division of the entire city into various District Metering Areas (DMAs)
2. Hydraulic study of DMAs, each comprising about 1000 connections.
3.100% Consumer metering, Bulk metering and District Metering set-up.
4. Water balance and estimation of NRW/UFW in each DMA
• Leakage detection, Repairs / Rehabilitation / Replacement plan
• Water balance of each DMA
• Install pressure regulating devices for equitable distribution
• Digital mapping of the utility on GIS compatible base maps.
• Hydraulic modeling of the entire network.
• Introduce / upgrade ‘SCADA’, the distribution management tool.
Approach
Universal Metering Policy Matter. It has been
accepted in principle and is
being implemented
Telescopic Tariff Structure
for Water Consumption
Policy Matter. It has been
implemented for certain
categories
Water Distribution Network
Up gradation
Hiring Consultancy Services and
Implementation of
Suggestions under their
supervision:
A Result Oriented Consultancy
Agreement
Reduction in UFW/NRW
& 24 X 7 Water Supply
Updating of water network maps with
universal reference points.
Present Status: Some part of the network has
been digitalized. Newly laid pipelines have
not been integrated in the digitalised version.
OBJECTIVE 1
OBJECTIVE 2
Estimation and Reduction of UFW for the entire city network.
I-Phase –
a) Providing Bulk Measuring Meters on various zones.
b) Estimation of UFW under intermittent water supply conditions by actual measurement of flows .
c) Reduction in UFW upto target level of 10% under existing conditions of intermittent water supply by implementing the suggestions
II-Phase –
Reduction in UFW up to target level as per minimum night flow on 24 hour basis.
Zone-wise hydraulic analysis of primary,
secondary and tertiary water supply
network.
Water balance in each zone
OBJECTIVE 3
24 x 7 Water Supply for entire city
(with available water supply which could be of
the order of 3500 Mld for a population of about
15 millions and NRW limited to 15-18%, it is
expected that the situation is conducive for 24
X 7 water supply.
The terrain, variation in population density are
the challenges in supplying water on 24 X 7)
OBJECTIVE 4
PRESENT STATUS
There are 11 outlets of Malbar Hill Reservoir varying in diameter from 450 mm to 1200 mm, passing through Chaupati Beach & further along the Netaji Subhashchandra Bose Road. Most of these mains are nearly 50 years old.
The rehabilitation of these outlets lines is very difficult because of social and physical cost impacts. Therefore, 8 out of 11 outlets are replaced by tunnel
Towards Better Demand-side
New housing projects with 135 lpcd
Recycling of Grey water
Telescopic water tariff to encourage the people to conserve water
Equitable Water Distribution
Technological Challenges
Replacement & rehabilitation of old water mains in confined space
Reliable and robust water leak detection equipments/systems
Reliable and robust water meters
Management consultancy in reduction in NRW in such a complex situation
Utility mapping for old pipelines
Quality Aspects
1. Protection of Water Sources
2. Treatment Facilities and adequacy
3. Possibility of Contamination of water
supply through water distribution
network.
General Characteristics of Raw Water
Turbidity: From lake sources-Max 20 NTU
From river source- Max. 50 NTU
pH 6.8 to 7.5
SS Max. 20 mg/lit
TDS Max 75 mg/lit
No hardness
No presence of any toxic material
Quality Assurance at Treatment
Plants
1. The entire water supply is treated at two major water
treatment plants: Bhandup and Panjarapur
2. The treatment consists of conventional treatment
units such as pre chlorination, Settling, filtration, post
chlorination. This treatment is adequate as all the
sources are away from inhabitation and well
protected.
3. There are full scale laboratories with trained staff and
state of art laboratory equipment
4. for quality control of water
5. The quality is fully ensured (as per IS as well as WHO
Standards) while the water leaves treatment plants.
Water Woes Summary
Intermittent Water Supply: Leading to ingress of water from
outside into water mains during non supply hours.
Sufficient water but unequal distribution leading to wrong
impression about availability.
Complicated procedure for new water connections
Low pressures in distribution system
Old pipelines which are heavily corroded
Hidden population: Census 2011 data shows declining
population of Mumbai- Creating problems for planning.
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