| Nanu Oya | |
| Subdivision Type1: | Country |
| Subdivision Name1: | Sri Lanka |
| Subdivision Type2: | Province |
| Subdivision Name2: | Central Province |
| Length: | 27km (17miles) |
| Source1: | Pidurutalagala |
| Source1 Location: | Central Province |
| Source1 Elevation: | 2000m (7,000feet) |
| Mouth: | Kotmale Oya |
| Mouth Elevation: | 12000NaN0 |
| Waterbodies: | Lake Gregory |
Nanu Oya is a 270NaN0 long stream in the Central Province of Sri Lanka. It originates at an elevation of over 20000NaN0 on Pidurutalagala, the highest mountain in Sri Lanka, flowing into the Kotmale Oya at an elevation of approximately 12000NaN0. The Kotmale Oya is a tributary of the Mahaweli River, the longest river in Sri Lanka, which finally discharges at Trincomalee after a combined distance of nearly 3500NaN0. The river was dammed in 1873 to create the popular Lake Gregory in Nuwara Eliya.[1] [2] The Nanu Oya discharges into the Kotmale Oya 2.5km (01.6miles) upstream of the Upper Kotmale Dam.