The National Disaster Relief Services Centre said up to 1,000 families had been displaced and in total more than 49,000 people affected by the floods. At least four deaths were reported. The government has so far allocated Rs4 million (about US$40,000) for immediate relief.
In the past 11 months, the country has experienced major floods on at least four occasions - in December 2007, this March and June and this week. Specialists blame the floods more on man than on nature.
"People think these floods are caused by heavier-than-usual rains, but that is not the case," SR Jayasekera, a deputy director at the Department of Meteorology, told IRIN. "Because we have either blocked the channels for rainwater or filled them, even 50mm of rain in a single day means a congested city like Colombo can be hit by flash floods."
Jayasekera said rainfall patterns had not indicated any major spikes in the past few decades. "There is no such increase that we can see, but what we do know is a lot of low-lying land has been filled [in urban areas]."
He told IRIN that tanks meant for water storage in rural areas had also become shallower due to sediment being washed in. "When there is no place for the rainwater to flow, it flows where it can."
Lack of planning
Irrigation experts say the lack of proper planning is one of the main reasons for the floods. "We are paying a very heavy price for these floods which are not that rare now," BK Jayasundera, senior deputy director at the Irrigation Department in charge of flood protection, told IRIN.
In June, flash floods in parts of the western province affected 418,000 people and left 23 dead.
According to statistics compiled by the National Disaster Relief Services Centre, at least 488,000 people were affected by floods in 2007 that killed 20 and damaged 9,800 homes.
More than Rs159 million (about US$1.4 million) was spent on relief and reconstruction following the 2007 floods, the centre stated. "This is money that we could spend on development if we had proper flood protection systems," Jayasundera said.
He said proper rainwater drainage systems needed to be maintained in cities while water retention schemes upstream would minimise flooding in low-lying areas that were prone to floods during heavy rains.
"We know the causes and the answers, but what we need is the will to put these plans to work," he said. "My house was flooded this week because when someone built the main road, they blocked the storm drain. It is the lack of planning [that is to blame], not heavy rains."