India’s Narmada Hydroelectric Development Corporation (NHPC) is finally going ahead with two hydro projects on the river Narmada in the state of Madhya Pradesh.
The corporation has called for international bids for the smaller of the two, the 520MW Omkareshwar project. Bids must be submitted by May, with construction scheduled for completion 48 months from the date of the award. The project comprises:
•Concrete dam, 73.12m high and 949m long, with ogee-type spillway, 570m-long crest with 23 radial gates (20x17m) and 18 construction sluices.
•Headrace channel (234m long and 208m wide).
•Eight penstocks (7.66m in diameter), with an intake structure that includes trash racks and raking arrangements.
•Surface power house (248x37x52m), with eight 65MW Francis turbine-generator units, and 220kV switchyard.
•Hydromechanical works, such as dam radial gates, intake gates, trash rack and cleaning machine, draft tube gates etc.
•Tailrace channel (250m long and 160m wide).
For the larger project, the 1000MW Indira Sagar, NHPC has called for bids for the hydromechanical equipment and for the erection of eight 125MW vertical turbine-generators.
Both projects have languished on the drawing board for many years, due to a lack of funds at the Narmada Valley Development Authority. Faced with a severe power shortage, the state government of Madya Pradesh joined up with the federal-owned National Hydroelectric Power Corporation to form NHBC on a 49:51 equity basis to release the funds needed to build the dams.