Sri Lanka is a picturesque island with a 1,620 kilometre-long coastline with numerous heritage sites, restaurants, hotels, and business establishments that cater to tourists in particular. This coastal belt around the country is also blessed with vitally significant coastal habitats such as lagoons, estuaries, bays, sand dunes, seagrass meadows, rock pools, rocky cliff edges, spits, rocky headlands, salt marshes, mangroves, sandy shores, coral reefs and beach mineral resources contributing considerably to the coastal livelihood and the sustainable development of the country as a whole.
However, coastal areas are subject to constant change. Weathering, sea level change, erosion, flooding and tidal variations can all shape and re-structure coastal areas. These natural phenomena as well as anthropogenic influences for years on have resulted predominantly in sea erosion which has become a perennial, socio-economic and environmental issue in Sri Lanka.
This comes to the fore as the most-talked about crisis mainly among the fisher folks in some areas and a great hue and cry about it crops up with the onset of the South-West Monsoon from May to September and the North-East Monsoon from November to February and dies down with these monsoons coming to an end. But the problem remains unsolved and is consigned to oblivion. True, some efforts were taken time and again, but the problem of the erosion of the coastline still persists having a serious negative impact on the lives of the coastal dwellers.
Effect on economy
This also causes long-term adverse economic consequences on account of tourist attractions being washed away by the sea. Ravaging sea waves have considerably eroded the South-Western, Western, and North Western coastlines of the country.
Fishing villages in areas such as the Negombo- Pitipana coastal belt; Iranawila, Ambakandawila, Chilaw and Udappuwa in Puttalam; Calido beach in Kalutara and the coastal belt in Mount Lavinia, Dehiwala and Ratmalana have been adversely affected by this environmental phenomenon.
The sea erosion in the North Western coastline has aggravated again and consequently many houses in about fifty fishing hamlets along the coastal belt from Wennappuwa to Udappuwa have been swept into the sea. The residents in the area said that the carpeted road from Chilaw to Wennappuwa is also in danger of being washed out to the sea. Puttalam District Organiser of the All Ceylon Public Fishery Federation Ajith Gihan said that unless appropriate measures are promptly taken, nearly 300 more houses could be devoured by the sea.
The pictures of the Iranawila coastline conspicuously show the gravity of this coastal erosion and environmental degradation caused by encroaching sea waves particularly during storms in the course of the South-Western monsoon period. An area of about one kilometre of the coastline northward has been eroded and two houses, one shop and many coconut trees have been swallowed by the sea. Also, several more business establishments in Ambakandawila in Chilaw including two prawn hatcheries where more than 10 million prawns were hatched and raised are on the brink of being razed to the ground by breaking sea waves.
Human activities
The Kalutara Calido beach and the coastal belt in Mount Lavinia, Dehiwala and Ratmalana have also been severely affected by the sea erosion and as a result, both the tourism and fishing industries have suffered. Hundreds of houses have been washed away by the sea. Since many tourist hotels are located in the area, it is imperative that immediate measures be taken to prevent the destruction caused by severe sea erosion.
Although coastal erosion has been a natural phenomenon since time immemorial, various, irresponsible, human activities such as breaking coral reefs, destroying the mangrove ecosystem, improper construction of coastal embankments, construction of various buildings on the beach have expedited the process of sea erosion.
Coastal erosion leads to various issues. The biggest problem thereof is the reduction of the land area due to the shore being gradually washed away to the sea. For example, the Seenigama temple was on the beach about 100 years ago, but owing to strong coastal erosion in the area, it is now about a mile away from the land. The destruction of houses, tourist hotels and coastal coconut plantations is another bitter consequence of this erosion. The number of tourists coming to beach side hotels decreases due to the smaller size of the beach behind them.
For all the numerous erosion mitigation strategies implemented in many places over the years, erosion rates at the sites affected have remained rather consistent resulting in the loss of natural sandy beaches and recreational opportunities as well as livelihood activities such as fisheries and tourism.
Successive governments took various steps from time to time and spent colossal amounts of money on many projects to mitigate sea erosion and some of the projects launched paid off to some extent, but the problem still remains unresolved for want of the implementation of a more pragmatic plan of work to stamp out the issue for good.
Protection measures
Both traditional coast protection measures such as constructing a series of groynes in selected areas, revetments, jetties, and offshore breakwater and soft engineering methods such as sand nourishments, maintaining setback lines and dune re-establishments have been implemented in the country for more than two decades to avert erosion.
One of the dominant methods adopted by the Department of Coast Conservation and Coastal Resource Management to prevent severe erosion is the construction of rock revetments where coastal erosion is serious. But rocks placed along the beach of some affected areas have been swept into the sea aggravating the issue.
As regards some other measures taken by the Department of Coast Conservation and Coastal Resource Management, several artificial beaches or stone ridges on the coast were built and are intended to be built in the future as well. Artificial beaches are constructed by pumping sand from deep sea to the land and spreading the sand.
When filling the Mount Lavinia sea area with sand, the Department had used a new technique called the Sand Engine Method, a type of beach nourishment where a large volume of sediment is added to a coast. The natural forces of wind, waves and tides then distribute the sand along the coast over many years preventing the need for repetitive beach nourishment.
