Tarbela Dam

Tarbela is the world's largest earth and rock filled Dam which was completed in 1974 as a component part of Indus Basin Project at a cost of US$ 2.63 billion. This 485 ft. high and 9000 ft. long dam has two-gated spillways having combined discharge capacity of 1.5 million cusecs and 5 tunnels for irrigation releases and power generation. It has a volume of 138,600,000 cubic yards (106,000,000 cubic m) .The dam forms a 100 sq. miles lake with gross storage capacity of 11.6 million acre ft. and live storage capacity of 9.70 million acre ft. of surplus water from Indus River for subsequent use for irrigation during low water season.

KEY FACTS

Dam Type:	Earth and Rock fill
Height:	485 ft. (above river bed)
Length of Crest:	9000 ft.
Crest Elevation:	1565 ft. SPD
Reservoir Area:	95 sq. miles
Gross Storage Capacity:	11.62 MAF
Live Storage Capacity:	9.7 MAF
Main Spillway Capacity:	6.5 million cusecs
Auxiliary Spillway Capacity:	8.4 million cusecs
Lake Area:	100 sq. miles
Year of Completion:	1977
Geology & Bedrock:	Alluvium under Main Dam and Limestone, Phyllite and Schist under the Abutment
Source of water:	Indus River
Power Generation:	3,478 MW

Objectives:

Following were the main objectives achieved by manufacturing Tarbela Dam:

• · Water storage for supplementing/regulating irrigation supplies.

  · Hydropower generation.

  · Increase in sub-soil water resources and perennial stream flows.

  · Minimizing runoff with consequent reduction in flood hazards & Environmental protection of the area.

  · Forest and rangeland produce.

  · Socio-economic condition of the people living in the area by improvement of land with consequent increase in agriculture.