The south-west monsoon brought widespread flooding to Western Province on Friday morning, submerging sections of the Colombo–Avissawella main road and forcing the diversion of at least six Bandaranaike International Airport-bound aircraft to Mattala Rajapaksa International Airport.

The Irrigation Department issued a minor flood warning for the Kelani River Basin valid for the next 24 hours after approximately 300mm of rainfall was recorded in the upper catchment areas. A parallel minor flood warning was issued for several areas of the Kalu Ganga basin. By Friday evening the Department of Meteorology said Pambegama in the Kegalle District had recorded the island’s highest 24-hour rainfall at 336.5mm, with Kirindiwela on 332mm, Frenrich Estate in Kegalle on 291.5mm, Kalatuwawa on 237mm, Labugama on 224mm, Hanwella on 216mm and Dummalasuriya on 215.7mm.

Floodwaters submerged the Colombo–Avissawella main road at the Puwakpitiya Thummodara junction, the Seethawaka Botanical Garden and parts of Yatiyantota, Newswire reported. Vehicular movement was also disrupted on the Delgoda–Belumahara Road in the Udupila area. Ada Derana said flooding had been reported at multiple locations between Avissawella and Hanwella.

At Katunayake, several aircraft inbound to Bandaranaike International were diverted to Mattala on Friday morning due to adverse weather conditions, with Newswire confirming at least six diversions. Airport authorities have not issued a formal statement on the total number of affected flights.

The impact extended beyond roads and aviation. Three wards at the Chilaw General Hospital in Puttalam District were inundated by the rainfall, Ada Derana reported, while six schools in the Dehiowita Education Zone in Kegalle District were closed for the day on grounds of bad weather.

The flooding escalates the situation flagged in pre-dawn landslide and flood warnings issued by NBRO and the Irrigation Department earlier on Friday, which had forecast rainfall above 200mm and placed Gampaha, Kalutara and Ratnapura districts on landslide alert. The south-west monsoon was declared established by the Met Department on 19 May, and pre-monsoon Kelani River basin flood defences were discussed earlier this week at a meeting chaired by President Anura Kumara Dissanayake. Authorities have urged motorists to remain vigilant and to avoid low-lying roads.

Sources