• Kospothu Oya • Dik Oya • Ratwila Ela • Kimbulwana Oya • Hakwatuna Oya • Maguru Oya • Kolamunu Oya • Delvita Oya Its
catchment area receives approximately 4,313 million cubic metres of rain per year, and approximately 27 percent of the water reaches the sea. It has a catchment area of 2,620 square kilometres. == References ==