"Our houses are flooded. We have become refugees overnight," 43-year-old Suresh Cabral of Colombo told the news agency of the U.N. Office for the Coordination of Humanitarian Affairs.
"Nobody expected rainfall of 330 mm [within a 24-hour period from May 19 to 20]," added Minister of Disaster Management Abdul Hameed Mohamed Fowzie. "This comes as a shock not only to the government but to everyone."
Though floods are common in the country due to the large volume of rainfall it receives each year, this week's floods have been described by some as the worst in the affected area in the past five decades.
"Over the last couple of years we have experienced similar rainfall, but we were able to continue using the Pamunugama Road," Nikulas Napolean of Pamunugama told staff from international Christian relief agency World Vision. "But this time we had to use an alternative road because the road is five feet under water and no vehicles are allowed to take the road."
Ajith Gomis, manager of World Vision's Negombo Area Development Programme, said the organization is working closely with the relevant divisional secretariats to assess the needs of the affected communities.
World Vision commenced an emergency response Wednesday night by distributing cooked meals to 2,500 people. Efforts were scaled up Thursday with over 6,500 cooked food packets distributed to affected families in Wattala, Ja-Ela, Kandana and Pamunugama areas.
"Dry rations distributed by the government with the assistance of WFP had reached only 5,000 people, but there are over 50,000 people who have been displaced in the Wattala area alone and the need for food is critical at this point," Gomis reported.
Though the Minister of Disaster Management said Friday that the situation has "calmed down a little bit," he noted that the worst may not be over as May marks only the beginning of the country's monthslong monsoon season.
The south west of Sri Lanka, together with the central hill-country, is commonly known as the "wet zone," receiving an average annual rainfall of 2,500 mm (98 inches). And much of the rainfall, brought on by the Southwest Monsoon, comes between May and September.
The first rainfall of this year's monsoon season, which reportedly came this year earlier than usual, arrived May 14.
On Friday, World Vision said it planned to continue the distribution of cooked food packets for at least three days, while it is also hoping to provide 5,000 liters of potable water per day.
A state of emergency, meanwhile, has been declared in the Nuwara Eliya district in the hill-country with warning of more rainfall and possible landslides in the coming days.