Lahore: The watershed management programme for Mangla Dam, which started in the early 1950s with the support of traditional approaches, has helped to enhance the life of the reservoir from 110 years to 212 years.
This was stated in a briefing given in a meeting presided over by Water and Power Development Authority (Wapda) Chairman Zafar Mahmood.
The consultants, in their project design for Mangla Dam, had estimated the life of the reservoir in the range of 100 to 110 years with a sediment load of 42,000 acre feet per annum.
However, the measures taken under the watershed management programme brought the sediment load down to 2,774 acre feet annually, adding more than 100 years to the life span of the reservoir.
The longer life of the dam was also resulting in benefits of billions of rupees to the country every year, the meeting was told.
The watershed management programme was being implemented since 1960 without any interruption in the reservoir’s catchment area, covering an area of 5,710 square miles in Azad Jammu and Kashmir and Pakistan in order to control soil erosion and reduce sediment accumulation.
Some of the measures taken include plantation of about 133 million trees and construction of dry stone and earthen structures in the form of check dams and walls.
Mangla Dam was constructed in 1967 and its height was enhanced in 2011. Now, the dam is the largest reservoir of the country with a storage capacity of 7.48 million acre feet, crossing the capacity Tarbela Dam which can store 6.4 MAF.
During the briefing, Wapda officials expressed satisfaction with the reduced rate of sedimentation in the Mangla reservoir. The authority has set the target of planting 1.325 million saplings over an area of 1,960 acres in 2015-16.
The meeting participants also decided that a third-party evaluation mechanism would be established by hiring the services of local non-governmental organisations (NGOs).
In addition to the plantation of trees, soil conservation structures and engineering structures will also be constructed during the current financial year under this programme.
