BASHA DAM KEY FACTS Dam Type: Zoned earth-rockfill with central core and concrete cut-off to bedrock Location: Chilas on the River Indus Height: 200 metres (660 ft.) (above river bed) Length of crest: 3,018 feet Reservoir Area: 27,700 acres Catchment Area: 152,100 km2 Gross Head: 145 m (476 feet) Average Flow: 1,970 m3/sec (69,600 ft3/sec) Design Flood Discharge: 19,300 m3/sec (682,000 cusecs) Total Storage Capacity: 9.0 km3 (7.3 MAF) Live Storage Capacity: 7.0 km3 (5.7 MAF) Total Volume of Dam: 58 million yards3 Total Volume of Fill: 44 million m3 Installed Capacity for Hydropower: 3,360 MW from 12 units Energy Generated: 14.1 GWh Spillway Type: Overflow, with concrete lined chute, flip bucket and plunge pool Spillway Gates: 6 – 16.6 x 20 metres (54.5 x 65.6 ft) 1.0 LOCATION OF BASHA DAM The Basha Dam project site has been identified about 314 km upstream of Tarbela dam on the River Indus and about 165 km south of Gilgit City. The development of a high dam at Basha will create significant storage capacity in the Indus valley between Rakhiot bridge and Dasu-Sazin gorge. The selected axis is the first suitable site for the construction of such a dam downstream of the relatively wide and flat reach of the river dominated by the town of Chilas. The dam site is located on a pronounced bend of the Indus River, in a section with steep rock slopes covered locally with a thin veneer of talus and acree. At the dam axis, the river is some 160 metres wide. The maximum depth of the river bed alluvium is 55 metres near the right bank. The bedrock has high strength, moderately jointed norite (a form of gabbro) and is suitable as fo undation and embankment material. The material constituting the riverbed is also compact and has low compressibility. However, its location requires the laying of long distance transmission lines to connect the hydel power generated to the national grid. 2.0 THE BASHA DAM PROJECT The project will comprise of a 660 feet high zoned earth-rockfill dam, a chute spillway with a flip bucket and plunge pool, one low-level and three mid-level outlets, intakes, water conduits on the right side and an underground powerhouse with an installed capacity of 3,360 MW. The reservoircreated behind the dam would have a gross capacity of 7.3 MAF and a live storage of 5.7 MAF. The average generation of hydropower by the project is expected to be 14.1 GWh.
