The metropolitan city faces increased risk of devastating floods when it rains and severe flooding in 2010 exposed the city's vulnerability to shifting patterns of torrential rain, which is linked to climate change.

The cost of the 2010 floods in the city is conservatively estimated at US$50 million and the Bank says it could have been much worse.

According to World Bank the rainfall frequency has almost doubled in Colombo over the last 30 years, suggesting that floods of this scale will happen with increasing regularity in the future, each time with potentially crippling economic consequences.

The Bank says it is an essential public investment.

Special Reporter