Sri Lanka rolls out plan to reduce flood losses in Colombo

By Amantha Perera

COLOMBO (AlertNet) - Whenever flash floods hit the Sri Lankan capital Colombo, Nayanajith Thilekeratne doesn’t have the luxury of suspending the bus service he operates between the city and the airport 30 km north, often leaving him out of pocket.

“You run the buses and then there are repairs - if one wheel gets damaged, you incur a bill of around $100. The problem is that we keep getting floods almost every month,” he said.

The last time he faced a big bill was in November last year when floods hit Colombo and its suburbs. Indika Cooray, who runs a small restaurant in Amour Street, also suffered.

In fair weather, his business occupies a prime location in the city, serving thousands who come to the neighbourhood in search of vehicle spares. But when it rains heavily, instead of patrons, he gets gallons of water coming into his restaurant.

“In the past two years, I have had to carry out repairs on four occasions due to floods,” he said.

The flooding is a costly nuisance for business people like these, not least because there are few measures in place to protect their assets.

But that could change as the Sri Lankan government rolls out an ambitious $233 million programme to ease the frequent headaches caused by flooding in Colombo. The fledgling project, which began in mid-2012, is due to be completed by the end of 2017.

Most of the funding - to the tune of $223 million - is coming from the World Bank, which is concerned about the debilitating economic impact of the flooding.

LOSSES UNDER-ESTIMATED

The Colombo Metropolitan region covers around 6 percent of the island nation’s land area, but accounts for half of national GDP and around 80 percent of industrial added value, according to the World Bank.

The bank analysed one of the worst flooding incidents in May 2010, when over 500 mm of rain fell in a day, and found that total losses were as high as $50 million. At least half of this amount was due to economic losses caused by forced suspension of business and lost orders, while the rest was largely infrastructure damage.

Rosanna Nitti, the World Bank’s team leader for the Metro Colombo Urban Development Project, said the loss figure was likely to be a significant underestimate. “The city has many such events (each year),” she added.

The flooding has been worsened by a drop in the city’s ability to absorb water due to the illegal filling-in of land near canals and marshes so those areas can be built on and the blockage of drainage systems by encroaching construction.

“In the last decade, 30 percent of (Colombo’s) water retention capacity has been lost,” said Rohan Seneviratne, additional secretary to the ministry of defence and urban development, who is leading the flood protection project for the government.

HEAVIER RAINFALL

Changing climate patterns are also exacerbating the problem for the crowded city, which is home to more than a tenth of the country’s 20 million people and has a population density of 3,330 people per sq km, 10 times the national average.

Rains are arriving in increasingly short, heavy bursts, causing traffic jams and inundating low-lying areas.

“Initial indications of climate change anywhere are the intensification of existing events,” said Sumith Pilapitiya, the World Bank’s lead environmental specialist in Sri Lanka.

Officials and experts involved in the flood preparedness programme told AlertNet that anticipated weather and climate shifts had been taken into account when the plans were drawn up.

“All these impacts are likely to worsen in the future due to effects of climate change; rainfall trends indicate larger loads on the system and sea-level rise impedes gravity drainage,” the project document warns.

Published in March 2012, it contains statistics that show rainfall patterns changing drastically, especially since 2000. Nitti said recorded daily precipitation has increased substantially. “The shift is tremendous,” she said.

Government official Seneviratne told AlertNet that a new hydrological rain mapping system developed for the project is running all possible scenarios and not leaving anything to chance.

“The intensity of the rains is becoming greater and greater - in certain instances, in half an hour, you get 50 to 60 mm of rain,” he said.

NEW LAKES, BETTER DRAINAGE

The promise of efforts to reduce flash flooding in Colombo is good news for small businessmen like Niranjith, who runs a three-wheel taxi and a small fruit stall near one of the main city hospitals. In 2010, he was parked outside waiting for a hire when he was swept away in flash floods. The repair bill for his vehicle was around $500 and he had to set up his stall again from scratch.

“When it rains, the canals are not deep enough, so the rain water takes to the roads,” he said.

The new project, launched last July, aims to stop that happening. The bulk of the funding - $150m - will be spent on flood and drainage management. At least six new lakes will be dug, and 16 canals and lakes dredged and rehabilitated. The project will also improve small-scale drainage systems in 16 of the most vulnerable of Colombo’s 45 flood-prone locations. 

The World Bank’s Pilapitiya said the growing risks posed by climate change mean learning lessons from previous events is no longer enough.

“In the past, you could have looked at history and planned, but now because of climate change impacts… you have to model for events increasing in intensity,” he said.

Amantha Perera is a freelance writer based in Sri Lanka.