Umtrew River originates from the west of the Sohpetbneng range in East Khasi Hills District
, near Lum Raitong. It flows towards the west till it meets the waters from the Umiam River which is being diverted by the Umiam Hydel Project. It then turns northwest and emerges at Burnihat where the Shillong-
road crosses this river. Umiam river and the Umtrew are being used stage by stage to form a continuous power potential hydel scheme till it reaches the plains.