An aerial view of the Diamer Bhasha Dam in Pakistan.
The Diamer Bhasha Dam, the world's tallest and largest roller compacted concrete dam currently under construction, successfully achieved closure on Dec 3, meaning construction will now begin on the main part of the dam.
The dam is being constructed by a consortium of POWERCHINA and the Pakistan Frontier Works Organization.
The dam has a maximum height of 272 meters, with a designed total concrete volume of 18.7 million cubic meters. It will a total installed capacity of 4,500 megawatts and is expected to generate an annual electricity output of 18 billion kilowatt-hours.
The method employed in this closure is the "single-sided and single-directional closure," which involves blocking the riverbed at once. Both the second diversion tunnel and the diversion opened channel discharge simultaneously, ensuring year-round water blocking for the upstream and downstream cofferdams. The flow rate standard of closure is set at 722 cubic meters per second, with a maximum flow velocity at the closure gap of 5.15 meters per second.
Overcoming challenges including the impact of the pandemic, climate, terrain, and flooding, the joint team addressed difficulties in importing construction materials and the high intensity of construction, ultimately completing the goals of closure to a high standard.
