Today's Paper

Seawalls can worsen erosion

A threat: According to the State of Environment Report, the granite structures are unscientific and threaten fishing and turtle nesting. — File photo  

Karnataka's coastline is being threatened by the very edifice that was designed to protect it.

Granite seawalls, constructed unscientifically along large sections of the State's 320-km coast to ostensibly protect the shore from erosion, are threatening the livelihoods of fishing communities and destroying coastal ecosystems, says the latest State of Environment Report for Karnataka, 2010-11.

These structures — essentially blocks of granite rock placed along the shoreline — have been installed along an eighth of the coastline, says the report compiled by Environment Management and Policy Research Institute (EMPRI) for the State Government.

Rs. 911-cr. project

This finding is particularly significant in the backdrop of the State Government's plans to construct permanent walls along the coast with a Rs. 911-crore loan from the Asian Development Bank, said author of the chapter on coastal zones Venkatray Nayak, professor at the Karnatak University PG Centre, Karwar. Minister for Ports and Environment J. Krishna Palemar, who made the announcement in February this year, said that the project would be completed by 2018.

Aesthetic value

While the walls will create a “fort” along the coast and impede turtle nesting, they will also make fishing operations difficult, says the report. It adds that the structure will also undermine the aesthetic value of the seashore for tourism.

Around 42 km of seawalls have been built at a cost of Rs. 40 crore along the shores of three coastal districts, namely, Uttara Kannada, Dakshina Kannada and Udupi, it says.

Site visits have revealed several environmental consequences. For instance, the seawall constructed in Devbagh beach (in Uttara Kannada) by Jungle Lodges & Resorts has actually increased erosion at both its ends and caused salt water intrusion into the paddy fields in the Nakhudamulla village area. The Devbag beach is also one of the best nesting grounds for Olive Ridley turtles, and the seawall has reduced the number of nesting visitors.

Erosion is a natural phenomenon, which occurs because of multiple reasons — wind, rain, of construction roads and jetties — and not just wave action. Therefore, seawalls cannot be the single solution, says the report. ‘Green walls', or vegetation cover, is a more sustainable alternative to preventing erosion, it adds.

Green walls

“The only solution is to protect dunes and dune vegetation instead of pouring boulders into the sea,” says the environmental report, which describes seawalls as “temporary relief, and eyewash [built] at the cost of taxpayer's money”.

Moreover, seawall construction has been ineffective in preventing erosion and involves large-scale quarrying of granite, it adds. In several places the walls are poorly engineered and built in the wrong places, making them vulnerable to erosion.

The State of Environment Report, Karnataka, will shortly be submitted to the Department of Ecology & Environment.

  • Report says ‘green walls' are a better alternative
  • About 42 km of seawalls have been built