There is need to construct more and mainly small dams/barrages in the country

By Dr. S.M. ALAM

Oct 25 - 31, 2004





Water plays a pivotal role in the country's economy. Although about 87 per cent of water is used in the agriculture sector, the industry, commerce and public health are also greatly affected by the quantity and quality of the available water. Per capita availability of surface water has been gradually dwindling in the country from 5400 cubic meters in 1951 to 1200 cubic meters in 2003. It has been projected that by 2005 per capita availability of surface water may hit 1000 cubic meters, which is a threshold for defining a water short country. The country's economy depends on agriculture. It is the single largest sector and accounts for 24 per cent of the GDP and employs 49 per cent of the total workforce. About 70 per cent of the country's total population lives in the rural areas and is directly or indirectly linked with agriculture for its livelihood. Over 70 per cent of our exports rely upon agricultural-based commodities. Irrigated agriculture provides 90 per cent of food and fibre requirements from about 22.1 mha. which is around 80 per cent of the cultivated areas, while the remaining is contributed by over 1 24 per cent of barani land. Pakistan has a total area of 79.61 mha. And out of this nearly 75 per cent is cultivated by irrigation water. Pakistan consists of four provinces, Punjab, Sindh, NWFP and Balochistan plus federally administered Tribal Areas. The total area of the country is 79.61 million ha. The economy of the country is basically agrarian and is heavily dependent on irrigation largely confined to the Indus Plain. Country is part of the sub-continent south of Himalayan mountains situated between longitude 61 and 67 E and latitude 24 and 37 N. The climate in Pakistan is arid to semi-arid with temperatures ranging between 2 and 50 C. The mean annual precipitation ranges from less than 4 inches to more than 30 inches.

Water provides important habitats for wild plants and animals. We use water in agriculture and industry, for leisure activities and of course for drinking. The uses of water are numerous and life without water is impossible. A man can live without food for longer than he can without water or air. Water is the earth's most prominent constituent and is an essential ingredient of all life. Water feed plants and irrigates lands, allowing farmers to produce varieties of crops in the fields. Without the use of water crop productivity is impossible. Application of fertilizer input to the farm lands without water is useless. The water we use eventually returns to watercourses. Even the water that evaporates will ultimately return to earth as rain which is beneficial for mankind. Pakistan is a watershort; but land-rich and demographically burdened country, where the population is increasing at a rapid race. At present, the population growth of the country is flourishing at a rate of 8 births per minute, 480 births per hour, 11,520 per day, 4,204,800 per year and so on. In this way, the per capita availability of water has been constantly decreasing for the last fifty years. According to the internationally recognized water scarcity indicators, the present level of water shortage in Pakistan hampers the growth and well-being of its people, and severe constraints may be caused to human life, if this downward trend continues. It is tragic that downward trend is continuing Tarbela and Mangla dams have lost 25 % and 20 % storage capacity because of salination.

Water is a key input for agriculture and is made available to farmers through irrigation network. The design cropping intensity for Pakistan's irrigation system was about 60-70%. In Pakistan, the task of irrigation system operation and management is in the hand of provincial irrigation departments. The government is spending heavily on the operation and maintenance of the irrigation system every year, but a shortage of fund is still the major problem. This situation has resulted in the deterioration of the canal irrigation system. There has been an acute and persistent shortage of irrigation water from river Indus and its canal in Guddu and Sukkur Barrage commandment areas posing major threat to both Kharif and Rabi crops. It must be mentioned that sowing of cotton, sugarcane and rice crops will possibly be delayed because of insufficient water supply in the kharif season. This barrage has seven canals on both sides, one of its canals, Nara is the largest in the world. Presently, some 2 x 104 - 2.5 x 104 cusecs (cubic feet per second, a unit to measure running water) water is being discharged from Guddu and Sukkur barrages. The amount is insufficient for the present day agriculture requirement. In the absence of regular yearly desalting, the water problem has aggravated further. Had there been regular extensive desalting, the water flow situation would have been better, even with less seasonal supply.



Pakistan is an agricultural country, and has been inherited with a monsoonal based economy. The country's economy depends largely on the vagaries of weather and the changing moods of rainfall, where in the north, it is high, while in the south, it is in decreasing order. It is an established fact that crop harvest of a farmland increase, if water supply is timely and adequate. Ultimately, a low rainfall causes a substantial short fall in harvests. South Asia has witnessed the changing global weather phenomenon over the last many years. It is reported that a few years back, Bangladesh and eastern part of India were lashed by heavy monsoon rains, but the rainfall in the western region of Pakistan and India were below the normal. The drought in some part of Sindh and Balochistan in Pakistan and in Rajasthan and Gujrat in India were a wake-up call for these countries. The winter rains during 2002-2003 were an excessively delayed with the result that the usually wet period of January and February was of (almost) the depletion of water from the once-mighty Indus river, which in fact has robbed the region of its historical importance and prosperity. The area, which once boasted of being the granary of the Indus valley, supplying culinary waves to towns and cities gradually glided with a barren land, unable to feed its own people including fisherman living on boats in river. The water shortage is the most serious crisis facing the country today. The Indus river system is its lifetime. But its canal command system is drying out of water. The mighty Indus presents a deserted look. Now, the cattle and animals are grazing and moving in the dried river beds of mighty Indus. The shortage of water is afflicting all the provinces of Pakistan.

The Indus River Basin System has multipurpose dams and reservoirs, nineteen barrages and headworks, forty-five independent main canals and twelve link canals covering about 90,000 chaks/villages/goths and stretching over 40,000 miles in the country. Available figures regarding existing water resources indicate that the quantum of water entering the rivers aggregates to about 145 million acre feet per annum. Of this, about 109 million acre feet is transferred to canals annually and the remaining 40 million acre feet flows down into the sea, because of lack of storing capacities. The volume of water entering irrigation watercourses from canals amounts to 78 million-acre feet per annum. Water obtained from about 700000 public and private tubewells for irrigation purposes has been estimated at 44 millions acre-feet annually. Thus, the total quantum of water entering the watercourses both from canals and tube-wells aggregates to 122 million-acre feet annually. The agriculture sector was never able to make optimum advantage of the available water resources mainly due to inefficient water management. Of the 145 million-acre feet water entering the canals each year, about 28 million-acre feet is lost in transit due to a number of factors. Besides, about 45 million-acre feet water is lost within the watercourses themselves. Hence, only 71 million-acre feet water reaches the fields. About 18 million-acre feet water is wasted in the fields. Taking into account all the losses only 51 MAF water is actually left for crop growth, while 98 MAF water per annum goes waste, which is estimated around 62 per cent of the total.

Three major dams Mangla, Tarbela and Chashma were constructed for the purpose of generating electricity and irrigating agricultural land.

Mangla Dam (on river Jhelum): Earth fill, height 380 ft above river bed, length 10300 ft, gross storage capacity 5.85 MAF, main spill way 870,000 cusecs. Lakes are 100 square miles, hydropower generation 1000 MW capacity, completed in 1967.

Tarbela Dam (on river Indus): Earth and rock fill, height 485 ft above river bed, length 9000 ft, gross storage capacity 11.3 MAF, spill way capacity 650,000 cusecs, lake area 100 square miles hydropower generation 1728 MW, completed in 1983. The dams have been constructed for the purpose of depleting capacity of the existing water reservoirs call for at least several small dams in the country to meet the water requirements. In view of the mounting gravity of the developing situation, there is art urgency of initiating a timely more to expedite development of adequate water resources to meet the increasing need of the economy adequately, without any more loss of time. According to expert opinion, situation demands that small dams are to be developed at strategic location with four provinces, so that rainwater can be used in the rainy days. In order to check/stop the waste of precious water in water irrigation channels and watercourses have to be put to desalting process on regular basis at least once a year. The growing shortage of water which reaches alarming proportions during the drought years requires that a concerted effort be made to conserve water, develop available water resources to the optimum and adapt modern technologies for efficient irrigation techniques. Unless this is done, self-sufficiency in food, socio-economic amelioration, alleviating poverty ad conservation of environment would not be possible and eventually food shortages and even famine- like condition may arise in the country. In order to meet the needs of the growing population for water supply and sanitation, food and fibre, industry and environment, the conservation of this precious resource and development of next generation water resource projects would be essential.

There is need to construct more and mainly small dams/barrages in the country at least seven in the Punjab, four in Sindh, three in NWFP and two in the province of Balochistan. The government has decided to construct Gomal Dam in NWFP, Hingol and Mirani dams in Balochistan, Thal reservoir in Punjab, Kachhi and Ranni canals in Sindh. These small dams would cost about Rs. 20 to Rs. 25 billion each and would have the capacity of storing 1.0 to 1.5 MAF of water. These would bring 200,000 to 300,000 acres of barren land under cultivation. Kachhi canal would alone bring 500,000 acres of barren land under cultivation in Balochistan, which would help boost country's cotton export by 4 to 5 million dollars. A part from these small dams, the government has approved installation of 10,000 tubewells in all the four provinces. Out of these 10,000 tubewells, 5,000 would be installed in Punjab, 3,000 in Sindh and 1,000 each in NWFP and Balochistan. Agriculture sector was an important segment of the economic revival plan, it constituted 25.6 per cent of the GDP and contributing over 70 per cent of country's foreign exchange earnings through the export of raw, semi-processed and processed products like cotton. Half of the country's work force was employed in the agriculture sector. Wheat production increased to 21.1 million tons and cotton output reached 11 million bales, while rice production attained the level of 5.2 million tons in the year 2001-2002. The names of some dams were appeared for, construction in the papers. Such dams are Bhashah, Munda dam, Chotiyarion dam also in Thar (Ravee Canal), and some barrage (Sehwan) and canals in Balochistan, NWFP and Sindh. During the last 30 years, no any new dam was constructed, thus we are neglecting this dire requirement of water for the country and thus country is today suffering for this criminal neglect in the form of drought and acute water shortage throughout the country specially Sindh and Balochistan. Punjab province has plenty of sweet sub-soil water and in case of shortage, it can meet its requirement by sinking more tubewells. But, Sindh has brackish sub-soil water, which cannot be used for irrigation purposes. The water shortage in Sindh province will be much more acute in the coming years and this disaster can be averted only by undertaking construction of new dams on war footing.

The vast and readily available groundwater resources of Pakistan have also played an increasingly important role in meeting the country's food and fibre requirements. Pakistan is fortunate enough to have an abundant groundwater as a consequence of gravity fed irrigation network. In all, about 80 per cent of the groundwater are from marginal to hazardous in quality and only 24.7 million acres are underlain by usable groundwater. Groundwater now supplies around 45 per cent or 42 MAF for crop water requirements in the country since it permits farmers to exercise greater control over available water in its timely application for crops. Water is recovered from pumping through 650,000 private and 15,000 public tubewells. However, usable groundwater with salinity level of less than 1,500 mg/l is very low for crops. At the same time, there are some areas where water logging still persists due to inadequate pumping and or drainage.

The third major source of fresh water is rain water. Estimated average annual rainfall in the cultivated commanded areas of the Indus basin is 23 MAF or 11.4 inches. In view of the fact that agriculture in rain-fed areas entirely depends on precipitation, there is pressing need to harvest more rain and conserve maximum moisture in these areas. The lowest limit for rainwater harvesting 50 to 80 mm of rainfall. In rain-fed areas of Pakistan rainfall varies from less than 100 mm to over 1000 mm with an average of about 400 mm annually. Domestic wastewater is widely used as a source in many parts of the world for a variety of purposes like soil fertilization, aquatic weed production and irrigation. High cost of artificial fertilizers and presence of valuable plant nutrients in wastewater justify a trade-off analysis for its use as irrigation water. It has been recommended that wastewater should be used in the country for irrigation only after secondary treatments to avert any damage to human health.

There is substantial loss of water from irrigation systems, especially from on farm facilities, due to inadequate management and maintenance. Inefficient use of water together with a lack of knowledge about modern agronomic practices is the biggest constraint to the improvement of agricultural productivity in the country. Therefore we need improvement of a farm water management system, improvement of water supply farm surface and groundwater, operation, maintenance, management and rehabilitation of water courses. There are a number of key issues relating to the water resources which confront Pakistan today. It is extremely important that at first step these issues are understood by parliamentarians and other stakeholders, and a second step, concerted efforts be made by them to resolve these major issues in the larger interest of the country, its people and the future generations. A system needs to be evolved to regulate pumping ground water to check lowering of water table in some areas and water logging in the other. A comprehensive plan for optimum conservation of water should be prepared and put into action. Feasibility study and pilot projects should be launched to assess the sustainability of new and effective irrigation technologies in the country. Improvement in the quality of domestic water in urban as well as rural areas is required besides ensuring satisfactory drinking quality water for the burgeoning population of the country.