Role of dams in the economic growth of Pakistan

Pakistan is located in a semiarid to arid region where rainfall is highly deficient and does not match the crop requirements. In most plain areas of the country it is less than 500 mm and is unevenly distributed over the year. As Pakistan is not an oil rich country, its economy depends on agriculture sector which accounts for about 23 % of the GDP and 42% of total employed labour force. It is also the largest source of foreign exchange earnings. Agriculture of country is mostly dependent on waters of Indus River System (IRS). IRS maintains World's largest integrated irrigation network called Indus Basin Irrigation System (IBIS). IBIS is fed with waters derived from Indus and its five major tributaries. As a result of Indus Water Treaty with India in 1960, Indus Basin Project (IBP) works were constructed during the sixties and the seventies. Two mega multipurpose projects (Mangla and Tarbela dams), five barrages, one gated siphon and eight inter-river link canals were constructed to regulate and convey water of western rivers to irrigation canals taking off from eastern rivers. Pakistan Water and Power Development Authority (WAPDA) completed the construction of all sixteen IBP components within a decade. Two multipurpose dams, Mangla (Live Storage 6.6 billion cubic meter (BCM), Installed Capacity 1000 MW) and Tarbela (Live Storage 11.9 BCM, Installed Capacity 3478 MW) were built on Jhelum and Indus Rivers respectively. These multipurpose mega dams provide about 70% of total existing storage capacity and hydropower infrastructure (producing one fifth of the country's electricity during 2007-08). These dams were constructed to regulate and supplement flows in irrigation network to sustain Pakistan's agriculture. These dams are operated primarily according to irrigation requirements of the country while inexpensive hydroelectricity is produced as a byproduct. This paper highlights the role of the two large multipurpose dams built on IRS to regulate flows i.e. Mangla and Tarbela commissioned in 1967 and 1976 respectively, in the economic development of Pakistan Careful analysis of four decades of historic data obtained after the construction of these dams from the canal head diversions of IBIS, when compared with the historic figures, reveals large volumes of additional flows are available for irrigation during low flow season. The paper also analyzes these dams role in providing hydroelectricity that sustains the energy sector of Pakistan. Moreover impact on the economic growth of the country due to failure to construct the mega multipurpose dam since 1976 to date is explored.