• 30 acres of land lost in Kalutara due to erosion
• Research-driven long-term solutions needed to save coastline 

Sri Lanka’s picturesque coastline is under severe threat from rampant coastal erosion, affecting not only the beaches but also critical infrastructure, historic venues, and the livelihoods of coastal communities.

From the urban beaches of Colombo to the tourist hotspots of the south and the fragile ecosystems of the east, the relentless erosion is a growing environmental and socio-economic crisis.

Experts and officials from organisations dedicated to coastal protection and Government agencies warn that the problem is complex and multifaceted, requiring careful, location-specific solutions rather than generic interventions.

Severe erosion of the coasts

“Instances around the country have shown a lot of severe erosion, which means there is a significant amount of coastal beach sands and even coastal roads being lost. In Colombo, there has been a lot of sand erosion. Wellawatte is emerging as a concern. Since 2020, large areas of sand have been washed away and are not replenishing, meaning more land is getting eroded,” explained Muditha Katuwawala, Coordinator of The Pearl Protectors, a civil organisation committed to protecting marine life and coastal areas.

Wellawatte, once a popular beach area of the capital region, is emblematic of wider challenges faced along the western and southern coasts.

“Similar cases have been observed in Angulana and Moratuwa. Going past Wadduwa down to the Kalutara area, a lot of erosion has taken place. Down south and in the east, specifically in Arugam Bay, erosion is evident,” Katuwawala added.

He cautioned that illegal coastal developments exacerbated the erosion, especially in the south.

“Many urban areas are experiencing significant erosion due to illegal coastal construction activities. For example, in the south in the Weligama and Midigama areas, many hotels have been constructed right on the beach. This has caused extensive erosion, and now the beach has disappeared, having been replaced by heavily constructed tourist areas.”

Such commercial constructions on the beachfront risked not only damaging the natural coastal buffer zones but contributed directly to the loss of coastal sand, he said.

Port projects and sand depletion

The controversial Port City Colombo project has also been implicated in accelerating coastal erosion, particularly near Colombo’s beaches. 

Commenting on this, Katuwawala opined: “There is some truth to the concern. Initially, Port City was constructed without an Environmental Impact Assessment (EIA) recommendation. Large amounts of sand were dredged from about 3–4 kilometres offshore, creating a sedimentation vacuum on the sea bottom that needs to be filled over time by sediment or sand moving into that area. This causes sand that should replenish the beaches to instead fill the dredged vacuum, leading to beach sand depletion.

“For example, the beach nourishment at Port City and Mount Lavinia, where sand was dredged from Angulana, along with other coastal constructions requiring sand, have contributed to erosion.”

However, while Port City is one factor, Katuwawala made it clear that it was not the sole cause, pointing to environmental destruction as another cause.

“Other factors include the removal of vegetation such as coconut trees, mangroves, morning glory, and marine grass. These roots hold the sand together, and once removed, contribute to erosion,” the environmental activist stated.

He warned that despite multiple causes, the observable fact remained that the popular beaches near Colombo had been heavily depleted of sand in recent years.

While the Coast Conservation and Coastal Resource Management Department was working to combat erosion, the responses so far had been a mix of short-term fixes and costly projects with mixed success, Katuwawala noted.

“Regarding Government efforts, the Coast Conservation Department is taking steps, such as addressing recent damage to the Kinross Club caused by erosion. However, so far, the Government has mostly focused on short-term solutions, some of which have proven detrimental.”

He alluded to the Mount Lavinia beach nourishment project as an example. “They filled sand hoping it would move north and replenish other beaches, promising protection for at least four years. But within two months, all the sand was washed back into the sea. These kinds of solutions, often applied by the Coast Conservation Department, have been ineffective,” Katuwawala charged.

He criticised the simple rock placements or sand additions used. “Common approaches involve placing rocks or sand on beaches, but these often lead to further beach loss. Instead, more nuanced solutions are needed, such as protecting nearby reefs, constructing wave breakers or piers that minimally impact beaches while protecting them.”

“The areas most in need of these measures include Moratuwa, where many low-income communities live at the edge of the sea, constantly fearing that their homes will be washed away. Wellawatte is another critical area, known as a nesting ground for sea turtles, but much of its beach has been lost. 

“Similar issues are seen moving north towards Uswetakeiyawa and at Calido Beach, where poorly planned solutions have worsened the issue. Further south in Galle, several beaches are under threat due to proposed port expansion projects involving wave breakers, which could divert currents and wash away sand from tourist beaches, risking tourism income,” Katuwawala said.

Balancing hard and soft solutions

Coast Conservation Department Chief Engineer (Coastal Development) R.P.S.D. Pathmasiri explained the structural interventions used to combat erosion.

“The hard solutions are mostly inserting rock structures. They have different names such as offshore breakwaters, revetments — which are the most common — groynes, and gabion walls. These are usually cost-effective options,” Pathmasiri said, acknowledging that “soft” solutions, like vegetation planting and beach nourishment, had roles but faced challenges.

“Soft solutions include growing plants such as mangroves that prevent erosion. But these are not suitable for areas that are facing severe erosion. Another soft solution is beach nourishment — this is where sand is taken from offshore locations and the beach is nourished with it. But the latter is very expensive.”

He cited Unawatuna and Browns Beach, Negombo as examples where beach nourishment had created artificial beaches. “There are a few instances where beach nourishment has been carried out in Sri Lanka — one example being the Unawatuna beach. The current beach we see is an artificial beach. The Negombo Browns Beach is a similar example where beach nourishment was done, and it is also now an artificial beach.”

However, Pathmasiri noted that such large-scale projects had not taken place recently due to high costs. “On average, the cost to do beach nourishment for a 2–3 kilometre stretch of beach would cost more than Rs. 1 billion at the moment. Such beach nourishment programmes have not been done in the recent past,” he said.

He added that the department tended to prefer hard structures for cost-effectiveness and long-term protection. “The most commonly used solution is the insertion of rock structures as it is the most cost-effective option which also provides a solid long-term solution in most cases.”

The Kinross Club in Bambalapitiya, once a magnet for the community, is now significantly impacted by sea erosion and has suffered major damage that requires immediate action.

“We have inspected the issues at the Kinross Club. Erosion has come right up to the swimming pool and the boundary has collapsed. We have determined that we would need to utilise revetment-type hard structures to curb and prevent further erosion. 

“We have discussed this with the management of the Kinross Club and they have agreed with our assessment. We are now awaiting budgetary allocations to be made to our department to go ahead with the revetment installations,” Pathmasiri said, adding that until the funds were released, sandbags had been installed to protect the club.  “We will be installing permanent protection via revetments early next year.”

Pathmasiri also identified the areas experiencing the worst erosion. “At present, the most amount of coastal erosion we are experiencing is in the Eastern Province, in areas such as Kalmunai and Nintavur. On the west coast, the worst erosion is in northern Kalutara on Abrew Road and in Waskaduwa. On the north-western coast, erosion occurs the most in Kudawa in Kalpitiya.”

He highlighted several protective measures underway, including groynes being utilised to stop erosion.

“In the eastern coast, we started putting in groynes beginning last year and it’s ongoing as of now. In the Kalpitiya area, we have planned to install protective structures next year and the Government will be releasing funds for this. 

“In 2025, we began installing protective structures in the Marawila fisheries region. In addition, protection projects for Abrew Road in Kalutara were begun this year and are continuing,” he said, adding that a total of Rs. 303.5 million would be spent on protective structures for 2025.

Beach erosion and land erosion

Coast Conservation Department Chief Engineer (Research and Design) D.T. Rupasinghe offered technical clarity on erosion types. 

“There is a difference between beach erosion and land erosion. For context, a beach is the sandy area between the ocean and the tree line where the mainland begins. Beach erosion is where the sand and sediment in the beach erodes. The normal cycle is that sand on the beach erodes during seasons such as the monsoon and then it is deposited back at other times. So there is an equilibrium, and the beach and its sand content remain the same overall.”

Describing when erosion became a serious threat beyond natural cycles, he said: “However, due to various external factors, if the sand is not replenished on the beach after monsoons or heavy weather conditions, then it is called beach erosion.” 

Land erosion happens when the erosion progresses beyond the beach. “If beach erosion continues over multiple seasons and years, and then erosion washes away the sand right up to the tree line and more, then it is considered land erosion — when land starts to get eroded.”

Rupasinghe said that authorities intervened early before land erosion became irreversible. “Usually we start protective measures before it gets this far — when we have identified a trend that the beach erosion is exceeding limits and will become land erosion.”

He noted that over 30 acres of land loss had occurred in the Kalutara area. “In the Kalutara area, land loss is taking place. We have calculated that over 30 acres worth of land has been lost in the area. However, it must be noted that these 30 acres also include land that was washed away near the river mouth — where the river connects to the sea — during heavy flooding. There is similar large-scale land loss occurring in the Eastern Province as well and we are currently in the process of calculating it.”

Nevertheless, Katuwawala emphasised that responses must be adapted to Sri Lanka’s unique coastal and climatic conditions.

“It is essential to customise solutions based on local conditions in Sri Lanka rather than replicating global models that do not fit our ocean and monsoon severity. Weather patterns have become more severe, and sea level rise is also a factor; therefore, experimental, location-specific solutions must be tested before full implementation,” he said. 

Katuwawala underscored the need for research and scientific basis despite difficulties in identifying exact locations for solutions. “There is a clear need for scientific, location-specific interventions throughout the coastline. Customising these solutions according to oceanographic and environmental conditions is crucial rather than applying random, globally sourced fixes.”

He emphasised that a unique approach for Sri Lanka’s coastal protection from sea erosion must be the action of the day. “A scientific approach tailored to each location is vital before implementing coastal protection solutions, learning from past experiences and focusing on protecting the environment while addressing the human and economic impacts of erosion.”

Sri Lanka’s beautiful beaches and coastal lands are not just natural treasures but lifelines for communities, tourism, and biodiversity. Yet, the multifaceted problem of coastal erosion calls for urgent action balancing engineering, ecology, community needs, and fiscal feasibility.