Via Pakistan Economist
WATER IS an important component of life. Three-quarters of the fresh water on the planet is held in the polar icecaps and glaciers and so is unavailable for use. Many parts of the world are confronted with water scarcity, for both irrigation and human needs. Some 70 per cent of the water, people use, goes to irrigation. Since 1950, the amount of irrigated land has tripled, and one-third of the world’s food is grown on it.
Pakistan is arid to semi-arid country, located between the longitude 61° east to 76° east and between latitude 23° north to 37° north. Total area of Pakistan is 79.61 million hectares. Population of the country is about 180 million and nearly 75 per cent of it lives in rural areas. Agriculture is the main stay of Pakistan’s economy, contributing 35 per cent to the gross domestic product and providing 60 per cent of the labour force. Moreover, nearly 60 per cent of the total export of the country originates from agriculture. Total annual cropped is about 19.72 million hectares. Out of which, 15.3 million hectares are irrigated areas, about 75 per cent (11.4 mha.) is irrigated through canals, l9 per cent (2.9 mha) through tubewells 2 per cent (0.3 mha) through wells and remaining 4 per cent (0.4 mha) through tanks and other sources. Major crops grown are wheat, rice, cotton, maize and sugarcane which together make about 63 per cent of the total cropped area. Production of three important crops – rice, cotton and sugarcane – as well as 90 per cent of wheat and most of maize is virtually confined to irrigated areas. The climate of the country is favourable for two crop season under irrigated during the year.
In Pakistan, the total water supplies available to agriculture come from three sources – rainfall, surface water – from the River Indus and its tributaries, and the ground water, and also from sewage water and sea water. The annual rainfall varies from less than 100 mm in Sindh to more than 1000 mm in the foot-hills and northern mountains with an average of about 400 mm. About 60 per cent of this rain comes during the monsoon season. Much of the summer rains are not available for crop production due to rapid run-off because of torrential showers. At other occasions, rain may be so light that the precipitation evaporates before the water can penetrate into the root zone. However, the contribution of rain to crops in the irrigated areas of Indus Basin is estimated at about 1650 thousand hectares meter. Ground water is the second major source for irrigation. There is a huge source of highly saline sea water along the 1,050 km coast of Pakistan along the Arabian sea but it cannot be used either for drinking or irrigation unless desalinized.
The irrigation system of Pakistan has been developed from the Indus waters more than hundred years ago and is now the largest integrated irrigation system in the world. The flow of Indus river system is the prime source of surface water resources of the country. It covers gross area of 16 million hectares of which 88 per cent is culturable. It has 48 principal canals, emerging out of 20 river diversion structures. Many of the canals are even large by world standard; 15 of them having capacities of over 280 cubic meter per second.
Presently, Pakistan irrigation system encompasses two major dams such as (I) Mangla – the main technical features of this dam is as: World’s third largest earth filled dam, built on river Jhelum; Height-380 ft. above river bed; Length 10300 ft. The worlds largest earth and rock-filled dam is one of the world’s most important river the Indus; height – 485ft. above river bed; length 9000 ft; gross storage capicity, 11.3 MAF; live storage capacity – 9.4 MAF; service spillway capacity 6,50000 cusecs; Auxiliary spillway capacity – 840,000 cusecs; lake area – 100 sq. miles. The Terbela dam is known as the best hydel power station in Pakistan having a capacity of generating 3,478 MW of electricity. The Chashma is the biggest reservoir, which helps in the irrigation of millions of hectares of agricultural lands.
In addition to the grand canal system, there are about 185,000 private tube wells with average capacity of 30 liters per second and about l5000 public tube wells of capacity of 60 to 120 liters per second. At present these tube wells pump about 41 billion cubic meters water and provide 30 per cent of the total irrigation water to exclusively more than two million hectares in addition to supplementing some canal fed areas.
Total available water resources of the country from the rivers as well as fresh ground water come to 160 million acre feet. Out of this, 101.4 MAF reaches at the modules or the starting points of the watercourses, after deducting losses of the system, i.e. seepage from the canal and distributaries, 35 MAF water was being wasted into the sea during flood season every year. Another available water 45 per cent is lost due to seepage from the water courses, which in absolute terms is 45.6 MAF, thus total water reaching at the farm gate remains about 56 MAF. About 15 per cent additional water is lost due to improper irrigation applications, which in absolute terms is 8.4 MAF. The total requirement of the country in the year 2000 is estimated to be 78.7 MAF, which means that there is a shortage of 22.9 MAF at the farm gate for which there seems to be no supplementary source at present. Pakistan would need 170 million acre feet of additional water in future to meet irrigation and other requirements of the people. This was not possible unless new storage dams were built. India was planning to build Salal Dam on the Chenab river and diverting the Indus river water from the Wooler lake in occupied Kashmir.
To overcome water shortage crisis, the solution lies in the proper water management at watershed, reservoirs, conveyance system i.e. at canals and distributaries level as well as watercourses and farm application levelling of open channels and use of pipes to transport water for reducing seepage losses. To prepare cemented water beds at the bottom of the base. Building of more dams in the country is also good solution to solve the problem of water shortage. We should build the Kalabagh dam for the betterment of the country from acute water shortage in future. However, officials of each province should be consulted for the construction as well as for equal share and distribution of water. It is also suggested that if any province was prepared some water out of his own share to other provinces it should be accepted as a gesture of good will and not as a matter of right. The Kalabagh dam project should be supplemented with supportive irrigation projects in Balochistan, Sindh, Cholistan and Khyber Pakhtunkhwa to take the benefits of additional water available from the Kalabagh reservoirs to take their respective areas. Experts say that it was the most researched and investigated project of the world approved by the world top irrigation and dam experts on which Rs. 1 billion had been spent so far on investigation. Recently, parts of Balochistan, Cholistan and some parts of Sindh had experienced drought and famine like condition a few months back where a number of casualties had been taken place besides the loss of 40 per cent of cattle.
The crisis of water shortage for irrigation can only be overcome and proper individual farmer for water management practices. Some of the points to be kept in mind are as: evaluation of available water resources, development and improvement of existing irrigation systems, judicious and efficient use of available irrigation water, control of evaporation from water surface in reservoirs and canals conjunctive use of surface and ground water, evaluation of water requirement of various crops, knowledge of modern techniques of crop and water management, active participation of farmers in water users association, better understanding between government and farmers community.
The tail end farmers on a watercourse do not receive their due share. This is due to prevailing technological and socio- political conditions. This unreliability of water supply at the tail ends of canals and watercourses due to the situation and distributaries and the presence of influential people at the head of canals seriously affects the morale and production of the tail end farmers. Reliability and equity of water distribution is imperative to provide opportunities to all farmers in a canal command area to increase crop production.
Massive education in proper use of water along with modern techniques of land leveling can save substantial quantum of water. To obtain the best results, effective co-ordinations between the departments of irrigation and agriculture is the cardinal point for success. Let we (Pakistanis) pray to Almighty Allah in a true sense for the betterment of Agriculture and for the rainfall to submerge our valuable dried lands for the cause of human remedy.