Umiam River emerges from the west of Shillong peak in
East Khasi Hills District. It flows through Ri-Bhoi and turns northwest. At a place about 20 km from
Shillong, the water of this river is dammed for Umiam Hydel Project. After that the waters from this reservoir are drained away through a tunnel to fall into the streams forming the tributaries of
Umtrew River. These streams flow in the western direction and meet the waters from the Umiam River which is further being diverted by the Umiam Hydel Project.
