Water as Leverage- Setting the scene for a call for action

Water as Leverage for Resilient Cities Asia Setting the Scene for a Call for Action Content
1.2.5
Coastal Erosion
Over the last 40 years, Chennai’s coast has suffered
from erosion caused by a combination of sea level
rise, changing ocean currents and hard water
constructions like harbors and dams. In some
places, up to 500 meters of coastline has been lost.
Forty percent of Chennai’s coast is currently under
threat of erosion. Because of the landward shift,
Chennai’s coastal aquifer has suffered damage,
decreasing its capacity. The coastal highway has
undergone substantial damage, cutting off transport
passing through the coastal corridor. Due to this,
around 5500 homes will have to be replaced in the
coming years.
Chennai’s coastal erosion
is a recent problem
caused by the construction
of sea harbours.
Chennai
Ennore creek
Buckingham canal
Kamarajar Port
Ennore Port
A relatively new threat to Chennai is coastal
erosion as a consequence of the construction
of sea harbors. The harbor docks block the
sediment flow, which runs northwards along
the coast, causing sedimentation south of
the harbors and erosion north of the harbors.
In terms of coastal protection, an area of
particular interest is Madras Harbor on the
northern coastline. The coast has recently
exhibited a disruption in sediment supply and
unpredictable behavior during the northeast
monsoon. As a consequence, the shoreline has
receded by 500 meters due to coastal erosion
since 1876 (Mani, 2001), the coastal aquifer
has suffered damage due to the landward
shift and the coastal highway has experienced
substantial damage, which has consequences
for traffic passing through the coastal corridor
(Sundar & Sundaravadivelu, 2005). It is
estimated that over the next few years, 5500
homes will have to be replaced due to coastal
erosion. As such, there are several programs
running to conserve the coastline.
Especially the area north of Ennore Port is
eroding fast, forcing 5500 households to move
within the next years. Measures to reduce
erosion, such as concrete seawalls and groins,
have limited effect and might even increase
erosion at certain locations.
Erosion
Accretion
The otherwise lively
coastal shore of
Chennai is also threatened
by erosion, which
has led to its severe
receding and damage.
162 CHENNAI
Water Issues
PART 2/Background Information on the Partner Cities
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