Loktak downstream Hydroelectric Project is located on river Leimatak in district Tamenglong in the western part of the state of Manipur and about 22km downstream of the power house of Loktak hydroelectric project. The project falls in Survey of India toposheet 83 H/10 (1:50000 scale) and is bounded between coordinates 24º44’00″N and 93º35’25″E. The project envisages construction of a 20m high concrete gravity dam above river bed level, a 5m dia,5.85 km long Head Race Tunnel, one 12.5m dia, 61m deep surge shaft and surface power house to generate 66MW comprising 2 units of 33 MW each.
1.1 GENERAL DESCRIPTION OF THE PROJECT
Loktak Downstream Hydroelectric Project (2 x 33 = 66 MW) is situated at Tausang and Thangal village in Nungba Division of Tamenglong District in Manipur state of India. The project dam has been proposed across Leimatak River which is about 90 kilometers from Imphal Town. The current access to the site is fair weather summer road connecting dam site at Tausang Khunou Village (90 km from Imphal) via Thangal and power house site is located at Irang (140 Km from Imphal) via Rengpang on National Highway No.53. The nearest broad gauge rail head and Airport are Dimapur and Imphal respectively. The project has been conceived as a run of river (RoR) scheme, utilizing the tail race discharge of Loktak Hydro-electric Power Station in addition to discharge of Leimatak river. The scheme envisages a medium height diversion structure (river bed El. ± 289.0 m) on Leimatak river and river discharge diverted through upstream water conductor system joins Irang river through tail race channel (river bed El. ± 159.713 m). A maximum gross head of 144 m between FRL and TWL (weir top) is planned to be utilized for energy generation of 334.22 MU in a 90% dependable year with installed capacity of 66 MW (2 Francis turbine/generator units each of 33 MW and single phase transformers).