The two largest lakes are: Lake Tondano (area of 4,278 ha) in Minahasa and Lake Moat (area 617 ha) in East Bolaang Mongondow. The main rivers are Tondano River (40 km), Poigar River (54.2 km), Ranoyapo River (51.9 km), Talawaan River (34.8 km) in Minahasa. Dumoga River (87.2 km), Sangkub River (53.6 km), and Ongkaw River (42.1 km) are in Bolmong and Bolmut.