The Rokan River Basin consists of 15 Watersheds, with the Rokan Watershed being the most dominant (Pola PSDA WS Rokan Lintas Provinsi, 2014). Originating from the Bukit Barisan range, which stretches along the western side of Sumatra Island, it flows eastward and empties into the eastern coast of Sumatra Island in the Strait of Malacca. The population growth rate in the Rokan River Basin i…