As delegates in Paris search for new ways to mitigate the effects of climate change, an innovative scheme that does exactly that is in the works in Sri Lanka.
Struck by a worsening cycle of floods and droughts, the Indian Ocean nation has begun planning for a $675 million project to capture heavy rainfall that can be used for irrigation in dry periods, as well as generating electricity.
The project will see two new reservoirs built, and 260 kilometres of canals that link existing reservoirs upgraded, across Sri Lanka’s “dry zone”, which stretches through the north of the country. Some of the extra water will also be funnelled into existing hydropower dams to generate 250 MW of new electricity. The Asian Development Bank is providing $453 million of the financing, while the Sri Lankan government and other donors will come up with the rest.
Planning began last month and the first stage of construction is scheduled to begin in February, while the government aims to complete the project by the end of 2024. It will vastly increase the amount of rainfall the country is able to retain. Most of it is now washed out to sea rather than being put to use.
“The problem in Sri Lanka is that it does not have the infrastructure right now to use the rainfall effectively,” said Lance Gore, an ADB Water Resources Specialist.
The project will cover an area in which about one third of the country’s 20 million people live, and will irrigate 350,000 acres of new agricultural land, according to the ADB. The bank estimates that 70 percent of the population in the region depends on agricultural for their livelihoods, while incomes in the area are 10 percent below the national average.
Unless Sri Lanka adapts to climate change, the country’s poorer population will suffer even more, warned the World Bank in a 2013 report. “Disturbances to the monsoon system and rising peak temperatures put water and food resources at severe risk,” it said.
Of all South Asian countries, Sri Lanka and the southern tip of India will be most affected by rising temperatures, with 20 to 30 percent of summer months experiencing “unprecedented heat”. Extremely wet monsoons usually occur once every century but are forecast now every decade, the World Bank report said.
Data from the Sri Lanka Meteorological Department shows that rainfall has fallen by about seven percent in the last 50 years, while average temperatures have been rising about 0.2 Celsius per decade. In the last five years, the dry zone has suffered at least five major floods and four droughts.
More than 52,000 people are currently affected by flooding in the Northern Province’s Jaffna District, while more than 320 are displaced due to the high risk of landslides in Badulla District, according to the UN's emergency coordination body, OCHA.
The drier regions of the country usually receive around 1,500 millimeters of rain annually, said Lalith Chandrapala, director general of the Meteorological Department. But over the last few years, the overall volume of rainfall has decreased while the intensity has risen.
“Take this year,” Chandrapala told IRIN. “We had about four months between June and October where there was hardly any rain in these parts, then in November third week, some parts got 350 millimeters of rains.”
Experts like Chandrapala say that Sri Lanka needs to upgrade its reservoir system, mostly constructed in the 1980s, so it can adapt to changing rain patterns.
“Now that the reservoirs are filled, we would not be able to hold the monsoon waters due later this month,” he said. “But when the drier months come, we need all the rain water we can get.”
According to information provided to OCHA by the Department of Irrigation, 17 of the country’s 72 major reservoirs are currently overflowing. The reservoir system is expected to come under further strain as the monsoon hits the northeastern region this month, and local disaster management authorities are on high alert, OCHA said.