Cyclone Ditwah caused one of Sri Lanka’s largest recent flood events, submerging about 1.1 million hectares—roughly 20% of the country—and directly exposing an estimated 2.3 million people to flooding, the United Nations Development Programme (UNDP) reported.
The storm made landfall on the eastern coast on November 28, bringing intense rainfall, widespread inundation and numerous landslides. UNDP’s rapid impact assessment, carried out with Sri Lanka’s Disaster Management Centre, highlights that these physical impacts worsened underlying socioeconomic vulnerabilities across several districts.
Nearly 720,000 buildings were exposed to floodwaters, including 243 hospitals and hundreds of schools. Severely affected administrative divisions included Dimbulagala (Polonnaruwa), Kandavalai (Kilinochchi) and Maritimepattu (Mullaitivu). Central highland districts—Nuwara Eliya, Badulla and Kegalle—recorded heavy rain that triggered more than 1,200 landslides.
UNDP combined satellite-derived flood maps, landslide records, infrastructure exposure and population density with its Multidimensional Vulnerability Index (MVI) to identify where cyclone impacts overlap with chronic fragilities. The analysis found that over half of the people in flooded areas were already living in households facing multiple vulnerabilities, such as unstable income, high debt and limited capacity to cope with disasters.
Many of the hardest-hit districts—including Batticaloa, Ampara, Mullaitivu, Kilinochchi, Puttalam and Nuwara Eliya—were already among the most vulnerable, with high poverty, limited access to services and fragile livelihoods. Damage to essential transport infrastructure further complicated relief and recovery: more than 16,000 km of roads and 278 km of railways were exposed to flooding, along with over 480 road bridges and 35 rail bridges, severely affecting mobility and access to services.
UNDP urged that early recovery efforts prioritize debris clearance, rapid rehabilitation of community infrastructure, livelihood support, restoration of personal and land documentation, and targeted measures to protect the most vulnerable groups. The agency warned that without swift, well-targeted assistance the cyclone’s impacts could push already-fragile communities into prolonged socioeconomic distress.
