Sone is the largest freshwater tectonic lake of Assam with an area of 3458.12 hectares (ha) at full storage level (FSL), 409.37 ha at dead storage level (DSL), maximum length 12.5 km, maximum breadth 3.9 km and shoreline 35.4 km. Sone is a syncline near the Badarpur line of folding and the Chargola anticline. It belongs to the Mio-pliocene epoch with alluvium in the Lake bed and fine grain sand stones in the catchment. The catchment also has evergreen forest. This Lake is continuously fed by the major inlet Singla which originates as Thing Tlawng Lui from the Mizo Hills (approximately 365 m MSL) and after traversing a tortuous course of approx. 62 km, it enters Lake Sone. The major outlet, river Kachua, drains the lake water into the river Kushiyara after traversing approx. 19 km from the northernmost end of the Lake.