Kala Oya

The Kala Oya is also Sri Lanka's longest rivers. It's around 145 kilometers (90 miles) long. It ranks 3rd among the longest rivers in Sri Lanka The river has a basin area of 2,873 km2 (1,109 sq mi), and it is home to almost 400,000 rural residents. In northeastern Sri Lanka, the Kala Oya River flows for 92 kilometers from Dambulla to Wilpattu. The Mahaweli River supplies around 75% of the river's water, with the rest coming from rainfall.

Its catchment area receives about 3,169 million cubic meters of rain each year, with about 5% of the water reaching the sea. It has a 1,792 square kilometer catchment area. The lower basin of the river is mostly used for rice irrigation, which is done on a large and small scale. Large-scale irrigation projects receive nearly 65 percent of the river's water.

Length: 2,873 km2 (1,109 sq mi)