446
14.4.2 Restoration of Vembanad Lake, Kerala
The Vembanad wetland system covers an area of over 2,033.02 km
2
thereby making
it the largest wetland system in India. Of this, an area of 398.12 km
2
is located below
the MSL and a total of 763.23 km
2
area is located below 1 m MSL. The lake is bordered by Alappuzha, Kottayam, and Ernakulam districts. It is situated at the sea
level, and is separated from the Arabian Sea by a narrow barrier island. Canals link
the lake to other coastal lakes in the north and south. The lake surrounds the islands
of Pathiramanal, Perumbalam and Pallippuram. The Vembanad Lake is approximately 14 km wide at its widest point. The lake is a part of Vembanad-Kol wetland
system which extends from Alappuzha in the south to Azheekkode in the north,
making it by far, India’s longest lake at just over 96.5 km in length. The lake is fed
by ten rivers flowing into it including the six major rivers of central Kerala namely
the Achenkovil, Manimala, Meenachil, Muvattupuzha, Pamba and Periyar. The
total area drained by the lake is 15,770 km
2
, which accounts for 40% of the area of
Kerala. Its annual surface runoff of 21,900 Mm accounts for almost 30% of the total
surface water resource of the state.
The most popular location on the shores of the lake is the Kumarakom Tourist
Village situated on the east coast of the lake. The Kumarakom Bird Sanctuary is
located on the northern fringes of Kumarakom village. The Vembanad Wetland system was included in the list of wetlands of international importance, as defined by
the Ramsar Convention for the conservation and sustainable utilization of wetlands
in 2002. It is the largest of the three Ramsar Sites in the state of Kerala. Vembanad
lake (Fig. 14.8) has been heavily reclaimed over the course of the past century with
the water spread area reducing from 290.85 km
2
in 1917 to 227 km
2
in 1971 and
213.28 km
2
in 1990. In the same period almost 63.62 km of erstwhile water spread
were reclaimed primarily for formation of polders and to enlarge the extent of the
Wellington island of Cochin port. The lake faces a major ecological crisis and has
reduced to 37% of its original area, as a result of land reclamation.
A unique characteristic of the lake is the 1,252 m (4,108 ft)-long Thanneermukkom
salt water barrier constructed as a part of the Kuttanad Development Scheme to
prevent tidal action and intrusion of salt water into the Kuttanad low-lands. It is the
largest mud regulator in India and essentially divides the lake into two parts – one
with perennial brackish water and the other with fresh water from rivers draining
into the lake. This barrier has helped farmers in Kuttanad by freeing the area of
salinity and allowing them an additional crop in the dry season. The Thanneermukkom
barrier is located at one of the narrower parts of the Vembanad Lake. Only twothirds of the original number of gates are opened in July to release flood flow. These
gates remain closed until mid-November. The main drawback of the structure has
been the loss of opportunity for fish and prawns to migrate upstream, and also an
increase in weed growth in the upstream, severely restricting the natural flushing of
pollutants. The Thanneermukkom bund has also created ecological problems, primarily, the rampant propagation of the Water Hyacinth in fresh water. Vembanad
Kol Wetland was included in the list of wetlands of international importance, as
R. Manivanan
14.4.2 Restoration of Vembanad Lake, Kerala
The Vembanad wetland system covers an area of over 2,033.02 km
2
thereby making
it the largest wetland system in India. Of this, an area of 398.12 km
2
is located below
the MSL and a total of 763.23 km
2
area is located below 1 m MSL. The lake is bordered by Alappuzha, Kottayam, and Ernakulam districts. It is situated at the sea
level, and is separated from the Arabian Sea by a narrow barrier island. Canals link
the lake to other coastal lakes in the north and south. The lake surrounds the islands
of Pathiramanal, Perumbalam and Pallippuram. The Vembanad Lake is approximately 14 km wide at its widest point. The lake is a part of Vembanad-Kol wetland
system which extends from Alappuzha in the south to Azheekkode in the north,
making it by far, India’s longest lake at just over 96.5 km in length. The lake is fed
by ten rivers flowing into it including the six major rivers of central Kerala namely
the Achenkovil, Manimala, Meenachil, Muvattupuzha, Pamba and Periyar. The
total area drained by the lake is 15,770 km
2
, which accounts for 40% of the area of
Kerala. Its annual surface runoff of 21,900 Mm accounts for almost 30% of the total
surface water resource of the state.
The most popular location on the shores of the lake is the Kumarakom Tourist
Village situated on the east coast of the lake. The Kumarakom Bird Sanctuary is
located on the northern fringes of Kumarakom village. The Vembanad Wetland system was included in the list of wetlands of international importance, as defined by
the Ramsar Convention for the conservation and sustainable utilization of wetlands
in 2002. It is the largest of the three Ramsar Sites in the state of Kerala. Vembanad
lake (Fig. 14.8) has been heavily reclaimed over the course of the past century with
the water spread area reducing from 290.85 km
2
in 1917 to 227 km
2
in 1971 and
213.28 km
2
in 1990. In the same period almost 63.62 km of erstwhile water spread
were reclaimed primarily for formation of polders and to enlarge the extent of the
Wellington island of Cochin port. The lake faces a major ecological crisis and has
reduced to 37% of its original area, as a result of land reclamation.
A unique characteristic of the lake is the 1,252 m (4,108 ft)-long Thanneermukkom
salt water barrier constructed as a part of the Kuttanad Development Scheme to
prevent tidal action and intrusion of salt water into the Kuttanad low-lands. It is the
largest mud regulator in India and essentially divides the lake into two parts – one
with perennial brackish water and the other with fresh water from rivers draining
into the lake. This barrier has helped farmers in Kuttanad by freeing the area of
salinity and allowing them an additional crop in the dry season. The Thanneermukkom
barrier is located at one of the narrower parts of the Vembanad Lake. Only twothirds of the original number of gates are opened in July to release flood flow. These
gates remain closed until mid-November. The main drawback of the structure has
been the loss of opportunity for fish and prawns to migrate upstream, and also an
increase in weed growth in the upstream, severely restricting the natural flushing of
pollutants. The Thanneermukkom bund has also created ecological problems, primarily, the rampant propagation of the Water Hyacinth in fresh water. Vembanad
Kol Wetland was included in the list of wetlands of international importance, as
R. Manivanan