Learning before disaster strikes

The devastating flash flood that struck the hills of Nepal last week is a grim reminder that disasters do not always announce themselves. In a matter of hours, a seemingly remote natural event can unleash destruction on an unimaginable scale, leaving hundreds dead and communities devastated. More than 500 people are reported to have lost their lives, although the exact circumstances behind the tragedy are still being assessed.

One explanation being examined is that a glacial melt high in the mountains may have caused a natural dam to fail, releasing a massive volume of water into a valley below. Whether this is ultimately confirmed or not, the tragedy highlights a larger and increasingly urgent reality of climate change and its altering of nature, frequency and intensity of natural hazards, while human settlements continue to expand into areas where the risks are poorly understood or inadequately managed.

There are many lessons to learn for Sri Lanka from this disaster. Floods, landslides, dam failures and sudden releases of water from reservoirs can have catastrophic consequences, particularly in the densely populated hill country and downstream areas.

The country already has laws governing construction along riverbanks, canals and other waterways. These provisions restrict or prohibit construction within reservations, require approvals from relevant authorities and provide for environmental safeguards. The precise setback varies according to the particular river or canal reservation declared by the authorities. The principle, however, is that areas exposed to natural hazards cannot simply be treated as ordinary land for construction and habitation.

Yet the reality on the ground is very different. Buildings have appeared in high-risk areas, sometimes alarmingly close to waterways and, in some cases such as the Mahaweli and Kelani along urban areas, seemingly encroaching into river systems themselves. Laws are of little value if they are not enforced. Every unauthorised structure erected on a vulnerable riverbank represents a potential future disaster involving lives, property and enormous public expenditure.

Sri Lanka’s ageing network of man-made reservoirs and dams, particularly those located in the hill country, are also a significant risk. The Mahaweli and Kelani reservoirs, many of them built decades ago, are subject to the relentless effects of age, weather and changing climatic conditions. The catastrophic breach of the Kantale Tank in 1986, a low-lying reservoir,  offered a sobering glimpse of the destruction that a failure of major water infrastructure can cause.

The Government must therefore undertake a comprehensive assessment of the structural integrity and safety of reservoirs and dams across the country. Particular attention should be given to structures located in mountainous and densely populated areas, where a sudden breach or uncontrolled release could send enormous volumes of water into communities downstream.

In addition, in the wake of increasing climate change-related disasters,  a culture of disaster risk assessment, mitigation and preparedness is essential. Hazard maps must be kept current. Vulnerable settlements must be identified. Emergency warning systems must be strengthened. Evacuation plans must be tested. Building regulations must be enforced without political or other interference.

 As Sri Lanka mourns with the people of Nepal, the tragedy should also serve as a warning and an opportunity. The most responsible response to a disaster elsewhere is not merely sympathy, but learning.