With the first anniversary of Cyclone Ditwah approaching fast, the risk of landslides in the hill country remains a matter of serious concern. The National Building Research Institute (NBRI) has warned repeatedly this year that slopes weakened during the cyclone could fail even under moderate rainfall.
The scale of the problem is not in doubt. During Cyclone Ditwah, some mountainous areas received over 500 mm of rain within 24 hours, against the 150 mm threshold at which landslides are considered likely. Rainfall in some areas approached 1,000 mm over 10 days. NBRO officials at the time described the situation as unprecedented. Satellite assessments by the Arthur C Clarke Institute later identified approximately 4,800 landslides, a figure considerably higher than earlier reported. By mid-December, over 70,000 people were still housed in relief centres, the majority in the Kandy, Nuwara Eliya and Badulla Districts.
In September, NBRI Senior Geologist Dr Wasantha Senadheera stated that 16,793 families had been identified as being at high risk following Ditwah. This is in addition to approximately 15,000 families identified over the past 15 years, of whom around 5,000 are being resettled. In effect, more than 30,000 families are now considered to be at high risk. According to the NBRI, soil and rock displaced during the cyclone may give way during further heavy rain, and areas previously considered safe may no longer be so.
The Government has taken a number of steps. In March, the Cabinet approved an increase in the financial assistance provided under the resettlement programme for families in landslide-prone areas, from Rs. 1.6 million to Rs 2.5 million per house. The Sri Lanka Army has been engaged in constructing interim shelters for displaced persons in the Kegalle, Kandy, Nuwara Eliya and Badulla Districts, and construction of 237 new houses commenced in the Badulla District this month. In December, the Deputy Minister of Housing, Construction and Water Supply told this newspaper that resettlement would be completed within one to two years. The Cabinet has also approved the preparation of a National Building Code, which Sri Lanka does not currently have.
These measures are necessary. However, they do not yet amount to a comprehensive response.
The first concern is hazard mapping. As this newspaper reported, the National Audit Office (NAO) has found that the country's landslide-prone zones have not been adequately mapped. The NBRI has stated that detailed maps at a scale of 1:10,000 require extensive field data, funds and time, and has attributed the delays to insufficient funding and staff shortages. Mapping has been under way since 1985. With approximately 30% of the country's land area across 14 districts classified as landslide-prone, this work cannot be delayed further. The NAO's recommendation that the NBRI expedite mapping and fully utilise allocated funds must be acted upon.
The second concern is enforcement. Since 2011, construction in landslide-prone areas has required NBRO recommendations, and landslide risk assessment reports are mandatory for building permits in high-risk districts. Unauthorised construction on slopes has nevertheless continued. The proposed amendments to empower Local Government authorities to intervene before such structures are completed are a step in the right direction, but they will be effective only if local bodies are prepared to enforce them consistently.
The third concern is the pace of resettlement. Identifying suitable land remains difficult, and families are understandably reluctant to relocate where doing so affects their livelihoods or their children's access to schools. These are legitimate considerations and must be addressed in planning. At the same time, every delay leaves families exposed to a risk that has already been identified by the State's own technical agency.
Several measures are therefore required. The Government should publish district-level data on the number of high-risk families notified, the number relocated, and the funds allocated and spent on resettlement. The NBRI should be provided with the resources required to complete detailed hazard mapping within a fixed timeframe. The National Building Code should be finalised and given legal effect without further delay. Local authorities must also be held accountable for approvals granted, or construction permitted, in areas designated as high risk.
Residents in landslide-prone areas continue to be advised to remain vigilant and to move to safer locations during heavy rain. Such advice is essential, but it cannot substitute for a sustained and adequately funded programme of risk reduction. A year after Ditwah, the authorities must ensure that the lessons of that disaster are reflected in action, and not merely in warnings.