Sinthay River originates from the Sinthay reservoir situated about 50km to the North of Naypidaw and flows pass a broad floodplain valley to eventually join the Sittaung River to the East of Naypidaw.
Sections of Segamat River in the town areas have been widened and levees raised during previous flood mitigation works.
Rajang River (or Rejang River) originates in the Iran Mountains in Borneo Island, then flows southwest to Kapit where it turns westward to finally discharge over a swampy delta into South China Sea.