Kotmale Oya

Kotmale River
Footbridge over the Kotmale Oya
Native name	කොත්මලේ ඔය
Origin	Horton Plains National Park
Mouth	Pallegama
Progression	Mahaweli River
Basin countries	Sri Lanka
Location	Kotmale, Nawalapitiya
Length	70 km (43 mi)

The Kotmale River (Sinhalese: කොත්මලේ ඔය ) is the longest tributary of Mahaweli River. The river begins as the Agra Oya, in the Horton Plains. The Central Plains have an annual rainfall of between 125 and 200 inches a year. The river is approximately 70 km (43 mi) long and drains a basin of about 58,534 ha (226 square miles). The river flows through a traditional area of ancient villages and tea plantations. King Dutugemunu spent his youth here. The Kotmale Oya flows into the Mahaweli shortly at Pallegama. Tributaries of the Kotmale Oya include the Nanu Oya, the Pundal Oya, the Puna Oya, and the Dambagastalawa Oya.

The river was dammed between 1979 and 1985 as part of a hydro-electric project within the Accelerated Mahaweli Ganga scheme. The opening ceremony took place in August 1985. Some 3,000 families had to be relocated top higher ground. The area has a history of geological instability.

See also

• List of rivers of Sri Lanka
• St.Clairs Falls
• Devon Falls
• Kotmale Dam
• Upper Kotmale Dam