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Municipal Corporation of
Greater Mumbai, India
Managing Mithi Drainage Basin
To Enhance Flood
Resiliency
Mumbai Topography and Drainage
Merger of 7 islands in Island City, 4
islands in Suburban District.
Surrounded by water on three sides.
Much of the area is close to sea level.
Gravity drainage system affected by
high/low tides.
During high tide ingress of sea water.
Island City has no natural drainage
outlet.
Mithi largest river flowing in Suburban
District
Catchment area 7265 hectares
Length approx. 17.9 km
Storm Water Drainage Network is
more than 150 years old designed for
rainfall of 25 mm per hour and run off
co-efficient of 0.5.
Rainfall Characteristics
Watershed degradation
Inadequate Storm Water
Drainage System
Increase in Impermeable
Surface Cover
944 mm in 24 hrs.944 mm in 24 hrs.On 26On 26thth July 2005July 2005
Vulnerability of MUMBAI
To Flooding
Urbanisation has increased vulnerability of
Mumbai to floods
Narrowing of banks for housing and slums
Reclamation of river beds by industrial units
Diversion of course of the river for construction of the
airport
Main river has been forced to turn 900 four times in
quick succession.
Some sections are bunded with walls and
embankments on both sides.
Reclamation of natural ponds
Reclamation of mangroves for construction of Bandra
Kurla complex.
Moraraji Nagar Slum EncroachmentMoraraji Nagar Slum Encroachment
Mithi on Kurla Mithi on Kurla Saki Naka RoadSaki Naka Road
Land use changes have increased
vulnerability of Mumbai to floods
Change in land use pattern has led to an increase in
run off coefficient to almost 1.0
Mithi River Flooding Mithi River Flooding 2626thth July 2005July 2005
Recommendation: Do not obstruct water flow of the
river
Initiatives taken since 2006
Widening & deepening of Mithi River is almost completed
940,406 cubic meters of silt and 492,000 cubic meters of hard rock
has been excavated from the river bed till 31st March 2011
Construction of R.C.C. retaining wall of 7.8 km length on both the
banks along with 6 to 12 mtr wide service roads.
Two weirs have been completed along the river.
4922 (residential & non residential) structures have been
demolished for widening the river, 663 structures remain to be
demolished
Expenditure incurred till 31st March 2011 69.8 Million Euros
Expected expenditure to complete the remaining work approx 71
Million Euros
Target date of completion December 2012
SAKINAKASAKINAKA
Weir Wall at BamandayaWeir Wall at Bamandaya
New Bridge At Kranti Nagar
Upstream of Kranti Nagar Bridge
Before
Upstream of Kranti Nagar Bridge
After
BEFORE
AFTER
Recommendation: Develop Early Warning Systems
Installation of 35 automatic
weather stations at 28 locations
Console gives audible alarm
when the rainfall exceeds 10mm
in 15 minutes
Rainfall data is transmitted every
15 minutes to the EOC, MCGM
Flow Gauges have been installed
upstream of Mithi River and a
measuring scale has been marked
on the existing pier of
Krantinagar Bridge to indicate the
level of water in the Mithi river
and issue warning to the
population living downstream20
KRANTINAGAR
FLOODING SPOTS
CATCHMENT
BOUNDRY
IRLA PUMPING
IRLA NALLA
IRLA NALLA Br-A
IRLA NALLA Br-BGARWARE NALLA
IRLA NALLA Br-C
Recommendation: Augment the capacity of the storm water drainage system to cater to the increase in runoff
ABHISHEK NALLA
Nalla training work
completed Work under SRA
development
FLOODING SPOTS
1 Milan Subway
2 VM Road
3 Near Cooper Hospital
4 JVPD Area
5 Near Vile Parle Station
6 Sahar Road Junction
1
2
3
4
5
6
Work of training yet to
start (funded by
MCGM)
Work of training under
progress
Existing Trained
KOLE DUNGARI NALLA
Pumping Stations
Storm Water Pumping Station at Irla
Capacity 48 Cubic Meter / Second
No. of Pumps 8
Capacity of each pump 6 Cubic Meter / Second
Progress Inlet channel - Irla
Progress Irla
Recommendation: Prepare detailed Contour Maps to
identify the sub-catchment and low lying areas
A contour map of Mumbai with 0.2 m interval has been
completed
Recommendations
Conserve wet lands
The reclamation of mangroves
for construction of the
Bandra Kurla complex has
increased the likelihood of
flooding.
Promote recreational
activities along the banks
of the river
GOALS OF DRMMP
Recommendation: Preparation of a comprehensive
Disaster Risk Management Master Plan
Policy Recommendations
Make flood risk and flood hazard
assessments an integral part of the
master planning process
Record construction details along with
the plinth and ground level in a master
inventory
Provide flood-resistant temporary
shelters
Municipal Corporation Of Greater Mumbai
Thank You
Making Mumbai a better and safe place to live in