The Maini River, formed by a confluence of mountain streams from Lusai and Long Torai and other areas, runs along Khagrachhari's eastern Dighinala before merging with the Kaptai Lake. The river's name derives from the words 'Maini Ha' in the native language of Tripura, which roughly translates to 'the land of paddy', due to the fertility of the surrounding land. However, tobacco plantations have now overtaken the banks of the river.