Pakistan’s water storage capacity dictates the need for constructing multipurpose dams for availing significant socioeconomic benefits. 

Water is life, a basic requirement of all living beings. Unluckily, the water resources of Pakistan are depleting day by day due to population explosion, environmental degradation and poor water management practices. The inadequate and haphazard management of water resources is adversely affecting the socioeconomic aspect of our country. Pakistan’s water supply, per capita, has decreased drastically in the last decade. In case we do not construct further dams, it will lead to acute water shortage resulting in hunger, starvation, and malnutrition coupled with a drastic decrease in hydropower generation and agriculture. The Center for Sustainable Economies (2013) at the U.S. Institute of Peace noted that Pakistan is heading towards extreme water stress and the resulting tension carries the risk of internal instability or even regional conflict considering Pakistan’s competition with India for water.
On the other hand, humans have been shaping earth’s landscape since the beginning of our existence. In the same way, dams are constructed to manipulate and divert water bodies to benefit the population. Dams have become an integral part of the basic infrastructure by offering numerous benefits such as irrigation, hydropower, domestic and industrial water supply, flood control, drought mitigation, navigation, fish farming and recreation. Developing communities face a different level of cost-benefit analysis than developed communities when it comes to large infrastructure developmental projects. The International Commission on Large Dams (ICOLD) affirms that large dams have a height of 15 meters or more and according to the International Union for Conservation of Nature (IUCN) more than one million cubic meters of water storage area is referred to as large dams. Dams are the primary example of a large infrastructure project that present an opportunity for multidimensional socioeconomic gains. Dams, like any other major infrastructures, have economic, environmental, and social benefits and costs. Accordingly, dams must be properly planned, built and managed with the best scientific and technical knowledge available.
Pakistan's economy depends on the agriculture sector which accounts for about 23% of the GDP and 42% of the total employed labor force. It is also the largest source of foreign exchange earnings. The agriculture system of the country is mostly dependent on the waters of the Indus River System (IRS). IRS maintains the 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. The Indus Waters Treaty (IWT), brokered by the World Bank, was signed by Field Marshal Muhammad Ayub Khan, the then President of Pakistan, and Indian Prime Minister Jawaharlal Nehru in Karachi; 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 the water of western rivers to irrigation canals taking off from the eastern rivers. The IWT provides control over Beas, Ravi and Sutlej rivers with a mean annual flow of 33 MAF to India, whereas the control of water over three western rivers, Indus, Chenab and Jhelum with the annual flow of 80 MAF to Pakistan. Pakistan’s Water and Power Development Authority (WAPDA) completed the construction of two reservoirs of Pakistan – Mangla Dam (completed in 1967) and Tarbela Dam (completed in 1976) – along with all sixteen IBP components within a decade. WAPDA engineers, scientists, security formations and other officers/officials deployed for the construction of the abovementioned national infrastructure performed their duties in an exemplary manner. In Pakistan, WAPDA is a pioneer in development and exploitation of fisheries resources in large man-made reservoirs. Two multipurpose dams, Mangla (live storage: 9.13 billion cubic meter (BCM), installed capacity: 1000 MW) and Tarbela (live storage: 14.3 BCM, installed capacity: 3478 MW) were built on Jhelum and Indus Rivers respectively. These large multipurpose dams provide about 70% of the 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 networks to sustain Pakistan’s agriculture. These dams are operated primarily according to the irrigation requirements of the country while inexpensive hydroelectricity is produced as a byproduct.

It is irony of fate or preference of priorities that after the construction of Mangla and Tarbela dam we could not build even a single large dam in Pakistan; Diamer-Bhasha and Mohmand dams are in the initial stages of construction.

In 2019, United Nations revealed that by 2050 Pakistan’s population is expected to reach 403 million. It is estimated that Pakistan’s population will likely increase by 178 million. Such increases are likely to enhance water demands and place pressure on the national water resources. Large-scale storages will be necessary to supply water to major urban centers, assure necessary food production, employment and electricity generation, ensure ecosystem conservation and mitigate the adverse impacts of floods and droughts.
It is irony of fate or preference of priorities that after the construction of Mangla and Tarbela dam we could not build even a single large dam in Pakistan; Diamer-Bhasha and Mohmand dams are in the initial stages of construction. Whereas, under the flagship project of China-Pakistan Economic Corridor (CPEC), the Karot Hydropower Project being built on River Jhelum has achieved 90% completion in its construction. The 720 MW Hydropower project is estimated to become operational by April 2022.

Pakistan has extremely limited water storage capacity due to a deficit in major infrastructure; the Indus Basin can barely store 30 days of water, compared to India’s major rivers which have a storage capacity for 170 days.

Moreover, under the Early Harvest project of CPEC, the 884 MW Suki Kinari Hydropower Project – being constructed on River Kunhar – is projected to become operational by the end of next year in 2022. 70% of the construction work has been officially completed.
Added with the Diamer-Bhasha and Mohmand Dam, these four hydropower projects will not only increase Pakistan’s overall water storage capacity but also aid in elevating the building pressure on its water reserves. However, with the construction of these dams, the unavoidable requirement for large dams will still be there for sustainable development. 
Sowa (2013) noted that Pakistan has extremely limited water storage capacity due to a deficit in major infrastructure; the Indus Basin can barely store 30 days of water, compared to India’s major rivers which have a storage capacity for 170 days. In Pakistan, every year during the monsoon rains the unstored water results in a widespread devastation in terms of loss of life, loss to moveable and immoveable property, in addition to other losses. It is pertinent to mention here that in our country, 30 MAF of water per annum flows into the Arabian Sea without any use. A UNDP study (2016) conducted on developing countries concluded that the construction of multipurpose dams not only supports and sustains economic development but also helps to encounter global climate change.
Pakistan is an agricultural country that is naturally gifted with four different seasons, but we are not self-sufficient in producing crops, vegetables and fruits, etc. In case of availability of required quantity of water (we are facing 36% shortage in our water requirement) and with proper practical application of the latest agriculture concepts, techniques and technology, we can fulfill at least our own food requirements. We are neither in the dark ages nor have we pledged to act as a stumbling block in the development and socioeconomic uplift of Pakistan. The importance of large dams for the socioeconomic development of countries and their population cannot be denied. It has contributed significantly to the economic and social growth of entire countries in the past and it is becoming even more important due to the fundamental role it can play in the search for water, food, energy, and climate securities at the national, regional, and global levels (USIP, 2013). With the increasing need for water, energy and food, the construction of dams to provide much needed services can only continue in the foreseeable future. As such, policies and politics as well as the management of financial, human, natural, and other resources required should be reassessed as part and parcel of the evolving developmental framework and societal needs of the country.

In 2019, United Nations revealed that by 2050 Pakistan’s population is expected to reach 403 million. It is estimated that Pakistan’s population will increase by 178 million. Such increases are likely to enhance water demands and place pressure on the national water resources.

The important socioeconomic benefits of large reservoirs are spelled out below: 
Water Storage. The reservoir of a dam is a vast expanse of stored water formed by earth or masonry work. The multipurpose reservoirs store water during rainy season, snow melting and floods. The reservoirs of dams store an adequate quantity of water for a number of purposes. The water of a reservoir is supplied through spillways and irrigation tunnels coupled with tunnels specified for a powerhouse. The general strategy followed for water storage in dams is to decrease water discharge during peak flood seasons and increase discharge during dry seasons. Water storage of a large dam/reservoir is a perenial, reliable and regulated water source.
Irrigation. Reservoirs provide water for irrigation purposes to grow crops.
Flood Control. Uncontrolled floods cause devastation to the lives and properties of people. Dams control flood water and convert catastrophy into prosperity.
Hydroelectric Power Generation. The growing energy needs and economic constraints in energy investment, as well as climate change, recognize the fundamental role of hydropower. Hydropower is the first step towards the use of renewable energy in terms of large-scale electricity generation. Hydroenergy is a renewable, clean, and cheap source of energy as it is powered by water which is a natural source and environmentally friendly. In terms of renewable sources of energy, hydropower represents – at present – the largest renewable source for power generation in the world (Tortajada, 2015). Hydropower is clean, efficient, dependable and largely renewable. Developing countries with the topography for dams can plug the much needed energy gaps that are required for development. 
Exploitation of Aquaculture/Fisheries. Water of large dams offers potential for aquaculture and fisheries through farming different species of aquatic animals and plants in a nonconsumptive use of water. Reservoir fisheries is a good and cheap source of animal protein. A reasonable amount of revenue is also derived from the sale of fishing rights of reservoirs. Nowadays, aquaculture is a rich source of food, revenue and jobs.
Navigation. Large dams are also an efficient way for inland navigation in terms of transportation of men and material. In many cases it has shortened the distance in water and time of transportation in areas located in the vicinity of dams as compared to land routes.
Conversion of Bare Land into Irrigated Fertile Land to Grow Agriculture-based Life Commodities. With the impoundment of reservoir water, it is a common phenomenon that after water storage in a large dam, the water in downstream areas decreases the water table, resulting in a decrease in the cost of lifting groundwater to grow high yielding crops and thereby convert barren land into fertile land.
Generation of Employment Opportunities. With the construction of large dams and allied infrastructures i.e., powerhouses and grid stations etc., new job opportunities are created in different fields/disciplines. The Suki Kinari Hydropower Project has created a total of 4250 job opportunities, whereas 4870 job opportunities have been generated by the Karot Hydropower Project.
Earning of Foreign Exchange through the Sale of Agriculture and Aquaculture Commodities. With practical implementation of the latest agriculture and aquaculture technologies by using reservoir water, high-yielding crops and quality food fishes can be cultivated/cultured to earn foreign exchange.
Collection of Scientific Data. In order to improve our knowledge for the construction of new dams in the future, scientific studies in the field of hydraulic structures, seismology, hydrodynamics, aquaculture and fisheries, sonar survey, hydrology, geology, ecology, dam engineering and safety may be carried out on the existing dams.
Recreation, Angling and Tourism. Large dams and reservoirs offer ample opportunities for recreation and tourism for the public to spend their holidays and leisure times. Reservoirs are considered as an angling paradise by amateur anglers.
Wildlife Habitat: The dams constructed on rivers alter the reverine ecology into lacustrine, resulting in a change in fauna and flora of the newly stored reservoir. The newly impounded reservoirs serve as a good habitat for aquatic animals and aerial birds including the migratory species. It also serves as a breeding ground for native and exotic fishes. Almost one million birds migrate from Siberia to different waters of Pakistan in which Tarbela, Mangla and Chashma reservoirs are also included.
Drinking Water. Large reservoir water is a reliable source of drinking water which is also used for industrial purposes. The water of the reservoir is liked by people during summer season.
An Effective and Efficient Way to Regulate Water Resources. Large dams effectively and efficiently regulate stored water as and when required. Nowadays, telemetric system has been introduced to confirm the volume/quantity of water discharged through reservoirs/dams.
In view of the above discussion and in the light of the different related studies conducted at the national and international level, it can be safely concluded that the construction of further large dams for a country like Pakistan is unavoidable for sustained development and socioeconomic gains.

The writer is former Deputy Director of WAPDA and visting Assistant Professor, Hazara University.