Artificial reefs to protect coast

Polypropylene wave arresters to check sea erosion in Ullal

Every monsoon, soon after such devastation, MLAs and ministers (including the Chief Minister) rush to the region and announce some token relief.  Boulders and sandbags are dumped to check erosion. And the ‘problem’ is forgotten until the next year when sea erosion starts again.

In a bid to put an end to this problem, A Rs 223-crore sustainable coastal protection and management programme funded by Asian Development Bank (ADB) is being implemented in Ullal.

The project will be taken up in three tranches and the total investment for Karnataka is $203.78 million (approximately Rs 911 crore) out of which the investment for Tranche I for Ullal is $52.45 million (approximately Rs 223 crore). Speaking to Deccan Herald, sources in the Department of Ports said investigations have revealed that the alignment of the beach in Ullal is not in equilibrium with the wave climate, with extremely large amounts of sand being lost to the south each year. At the same time, insufficient sand is being provided from the northern beaches and the river, due to several factors including the northern bias in the alignment of the breakwater.

The recommended solutions includes restoration of breakwater, that is, cutting South breakwater by about 150 metres (from the existing 580 metres) and extending North breakwater by 150 metres (from the existing 380 metres). The project includes construction of two submersible reefs (under sea) and three off-shore reefs, totally costing about Rs 180 crore. Each reef, made of polypropylene, will weigh about 1.5 tonne (dry weight) and it will weigh 4 to 5 tonne (wet weight) after the sand is pumped inside it. 

Approximately 70 such reefs will be placed in Ullal in about 200 metre area in a ‘V’ shape. The reefs break sea waves taller than a particular height, letting only low intensity ones to pass through. Sources also said that ASR Limited, a New Zealand-based marine consulting and research company providing environmental, engineering and advanced computer modelling expertise across Asia-pacific, Europe and America, has been appointed as consultants. The work on “Ullal coastal erosion and inlet improvement sub project” is expected to begin by December or January 2011 and it is expected to be completed by 2013-14. In the second phase, works on other erosion-prone areas like Mukka-Sasihithlu (DK), Paduvari (Udupi), Devbagh and Pavinkuruve (Uttara Kannada) will be taken up.

Failure in Kovalam

The objective of artificial reef is to protect the sea shore threatened by erosion and to improve the tourism potential of the area as the reef will lead to calm sea conditions. But the failure of the project in Kovalam (inaugurated in May 2010) has been a cause for concern. In fact, the Kerala Independent Fish Workers Federation and Kerala Tourism Watch, an NGO, has demanded from the Union Government and the Kerala state government, a comprehensive judicial and scientific enquiry, as well as a social audit to analyse the failed aspects and evaluate the overall process of the Artificial Reef in Kovalam.

“The ongoing washing up of geo-textile bags, the key component of the reef, to Kovalam and nearby sea shores, starting two weeks after its inauguration is a serious cause of worry. Diversion of Rs eight crore of Tsunami Rehabilitation Funds provided by the Planning Commission and meant for coastal communities was wasted on tourism infrastructure while tsunami-affected communities’ need for rehabilitation still waits to be addressed,” states a press release issued by them.

To a query, an official said the failure of Kovalam project may be due to faulty placement of reef.  The ASR Limited, the consultants for Mangalore project, were the consultants for the Kovalam project too.

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