White water rafting is a popular adventure sport in Sri Lanka. Some of the popular places for white water rafting include Kithulgala, which is about 90km from Colombo, and Kelani River. The experience usually takes about 2-3 hours, and you will be accompanied by an experienced guide.
The rapids in these rivers vary in grade from 2 to 3, and occasionally grade 4 during the rainy season. The best time for white water rafting is from May to December, but it may be available year-round depending on the water levels.