The most dreaded water scarcity event has at last hit Pakistan. This is nothing unexpected. The manner in which we have been used to handle our resources and national affairs, this catastrophic occurrence was bound to take us over. Nature’s endowment of water blessings upon Pakistan has always been envied by the world at large. At the time of independence 5000 cu/m of water was available for each Pakistani, which has now reduced to 1000 cu/m because of uncontrolled population growth.
Water is one resource that can not be generated it can only be preserved. Farsighted nations try to conserve each every drop of water available to them because they are aware of the fact that if this commodity is not prudently preserved and used, the human survival itself would be jeopardized and future wars would be fought for its possession and control. The only manner to conserve this resource known to man so far is to construct dams. Dams have been built for atleast 5000 years and, their functions have evolved with the developing needs of the society. Most likely, the earliest dams were built to store water for domestic and agriculture water supply. With the onset of industrial era, hydropower became a major reason to built dams. Presently dams are built to serve many other functions, such as, flood control, navigation, and recreation. According to an estimate the present volume of all storage reservoirs with gross capacity of 5 cu/km and above amounts to some 4900 cu/km. Out of this about 975 cu/km lie in North America while about 1770 cu/km are in Asia with majority in China. China has some 83000 reservoirs built for various purposes, of which 330 are major in size. While in Pakistan we have two major and about a dozen smaller reservoirs.
It has been said that all reservoirs are doomed to die. This is due to loss of their storage capacity because of sedimentation. Assuming a hundred year average life of reservoirs (Lake Mead, USA-350 years + Tarbela, Pakistan-40 years), the world is losing about 41 cu/km of storage capacity per year. Although we can not halt their termination yet, with our knowledge and effort we can delay this process and elongate their life. So far few methods are available for prolonging the storage and life of reservoirs. Among these the most frugal and resource preservation method is construction of series of dams on the river so as to trap the sediment inflows in the upstream reservoirs and store comparatively sediment free water in the lower reservoirs. It was estimated that Kalabagh reservoir life with Tarbela upstream and a conjunctive operation could be extended to 100+ years. The other operational methods include sediment sluicing alongwith water flows through the dam outlets and flushing of accumulated sediment through reservoir regulation methods; though these method involve trade off between stored water and reservoir capacity because stored water shall have to be passed through the dam unobstructed. Another method available is desiltation through dredging. This method is so expensive that construction of a new storage would cost about one twentieth of the cost of a similar reservoir.
Let us now recapitulate and make an assessment of ourselves to find out how and why we have suddenly become a water scarcity country from a water affluent country. Soon after the creation of Pakistan the country was faced with a number of serious problems including that of electricity and water shortage. The control of three out of five Punjab rivers had gone to India, which stopped the water supply to our canals feeding the eastern districts of theUnited Punjab and the Bhawalpur State.The unilateral action of the Indian Government ruined our cultivated land which was soon rendered dry and started becoming salinated. This affected the economy of the newly created country very badly and the danger of famine thus loomed over the nation. Pakistan therefore, had to mobilize her own resources. The search for alternate arrangements to sustain our mainly agrarian economy started. The construction of small dams on our rivers like Warsak on Kabul and Rohtas on Jhelum were taken up with the aid of Commonwealth countries. In addition, for gross utilization of the available water resources in the country, the Govt. of Pakistan set up an organization under the title “Dams Investigation Circle”(DIC) which was entrusted with the task of carrying out comprehensive survey for collecting the data and preparing the projects which may help in resolving the problems of water and energy shortage. By the end of May 1996, the DIC prepared a number of projects, which included Dams at Kalabagh on Indus River and Rohtas (later called Mangla) on Jhelum river.
Investigations for construction of a huge multipurpose dam on Indus River at Kalabagh were started in 1953 and its feasibility was submitted to the Govt. after getting approved by a group of expert foreign Consultants. The Govt. approved this in 1959, the year WAPDA came in to being. In 1960 a treaty between Pakistan and India was signed with World Bank mediation widely known as the “Indus Basin Treaty”. According to this treaty, control of waters of Ravi, Bias and Sutlej was given to India with the condition that the Indian Govt. will compensate for the loss of Pakistan and fully participate in the construction of the replacement works with the help of the World Bank and the other aid giving agencies. The replacement works included two large dams one on the Indus and the other on Jhelum, five barrages and eight link canals and a siphon for carrying the waters of Chenab River across the Sutlej River. The then Chief Martial Law Administrator and President Ayub Khan on behalf of the Pakistan Govt. and the Indian Prime Minister Pandit Jwaharlal Nehru on behalf of India signed the treaty; Eugene Blake signed the treaty on behalf of the World Bank. For the two large multipurpose dams on Indus and Jehlum Pakistan proposed sites at Kalabagh and Rohtas (later called Mangla). Kalabagh site choice for Pakistan was obvious since lot of investigation had been carried out at this site and a feasibility report duly prepared and approved by the GOP after check and scrutiny by the foreign experts and consultants.
In the meanwhile a group of shortsighted bureaucrats gathered around Ayub Khan and convinced him to switch over the construction site on Indus River from Kalabagh to Tarbela some 100 miles upstream. Unfortunately, Ayub Khan was neither a political leader nor had the wisdom to understand the implications of the counsel given to him. In fact it was some sort of intrigue weaved very carefully around Ayub Khan by some petty minded bureaucrats who had their own axe to grind rather than serve the national interest. On Ayub Khan’s insistence the design of dam at Tarbela site was prepared in great hurry, which was not based on detailed site investigations and thus had many inherent defects. The team of experts warned the GOP that this project would be a complete failure and the whole investment on this scheme will go down the drain. Incidentally no attention was paid to this warning. Ayub Khan soon came to know that the World Bank would not pay a single penny for this badly designed project of Tarbela Dam. Since, a large dam was part of the treaty, the GOP commenced work on Tarbela Dam out of the funds received for Kalabagh Dam and later approached other countries, who agreed to finance the project on terms and conditions favored to their interests. The reasons for switching over to Tarbela Dam were never made known to the public which ofcource was not in a position of raising any voice against the authority of the Martial Law Government. Kalabagh Dam was therefore thrown into the dustbin and all the resources were diverted towards Tarbela Dam. However, a lollypop was given to the nation stating that since it is intended to built a series of dams on the Indus river, soon after completion of Tarbela all machinery and trained man-power would be diverted towards construction of Kalabagh and later on completion of Kalabagh, these resources would be utilized for construction of dam(s)upstream of Tarbela at suitable sites.
Tarbela’s hurried and faulty design brought Pakistan near total catastrophe in 1974. It was only the Almighty that saved Pakistan from complete devastation. An accidental stuck-up of tunnel gates at Tarbela forced the operating authorities dump the full reservoir and when the reservoir was completely depleted it was found that large sink holes have developed on the immediate upstream of the dam. This is a phenomenon akin to silent heart attack, which results into sudden cardiac arrest without warning. With a newly full reservoir no one could visualize such a happening and one fine morning there would have been no dam resulting into the whole country being under 4-6 feet of water.
The story of Kalabagh does not end here. During Bhutto era need for another storage seriously cropped up and research and studies with the help of both local and foreign consultants were carried out to develop the Kalabagh feasibility studies into full fledge project design. This design was deliberated by top world experts on dam design, reservoir sedimentation and operation. Due care was given to various implications involved and engineering solutions based on sophisticated techniques were chalked out. During Zia regime the World Bank committed some U.S. $7.0 billion and kept this amount earmarked for about three years. Then suddenly an intrigue based on dirty politics sealed the fate of the Kalabagh Dam for all times to come. A powerful General who was Governor of NWFP in order to put pressure on Zia for reasons best known to them, in connivance with some Consultants started marking high flood level marks on the houses, graveyards, mosques and other permanent structures, and set a wave of alarm among the public of fear of their drowning. This disturbance among the people was played up so much that a strong resistance started developing among the inhabitants of NWFP against the Dam. Most unfortunately, these high flood level marks were neither based on facts nor had any basis. The dam designers in particular and the engineering community in general based on actual studies proved and showed that even in the worst scenario when both Tarbela and Kalabagh are full and an unprecedented historic flash flood occurs, the high flood level would not reach to a stage so as to cause any damage to the populace. With regard to the fear of waterlogging in the Nowshera valley adequate provision was made for tubewell installations as part of the Kalabagh project. But, the shot had been fired and before the NWFP people fears could be quelled, the Sindh Province came out with an entirely opposite objection to the Kalabagh Dam building i.e. drought and water scarcity. The controversy has reached to an extent that today almost every one in Pakistan has formed opinion either for or against the Kalabagh Dam.
If we look deep into the controversy we would clearly see the mistrust and distrust between the Provinces being an outcome of the suppression caused by autocratic rules and absence of democratic forces needed to freely vent and mitigate the negative forces.
Coming back to the water scarcity problem, we find that absence of additional storages have forced us to burden Tarbela most adversely by inflicting continued low level drawdowns which caused racing of large sediment deposits within the reservoir towards the Dam much before than expected. To retard the movement of sediment towards the Dam it was required to keep the minimum pool level higher so as to keep the delta away from the Dam and maintain the reservoir’s live storage as much as possible. For example, Tarbela minimum pool level initially was fixed at El. 1300 and later with the increase in sediment inflows was to be gradually raised to El. 1400 and if need arises even higher. But, successive dry years forced us to operate the reservoir at lower levels and as a result the toe of the delta has almost reached upto to mouth of the intakes. As such, this year we are forced to stop water releases from the reservoir at El. 1369 and, if we venture to lower it further all silt, sand and debris would pass through the power intakes and damage the turbines to an extent that the power house shall have to be closed for repairs involving heavy amount of foreign exchange.
The Kalabagh controversy started some 15 years back and during this period we did nothing but to concentrate on rhetoric for or against Kalabagh. Although it was known that consensus on construction of a new reservoir above or below Kalabagh will take some time and when it somehow gets finalized then preparation of its feasibility, design and then construction all would involve not less than 15 years. One preference for Kalabagh is that its designs are prepared and even the tender documents are ready.
It is a well-known fact that in the world most lucrative projects were conceived but resisted and washed out by envoirmentalists. That never was construed as end of the day. Planners always have alternate plans ready, which unfortunately we miserably lack. Prudence demanded that during the last 15 years we should have worked on sites other than Kalabagh and reached a level from where the actual construction commences. Not only that, we should have educated ourselves through research and study of Tarbela reservoir sedimentation processes and upgraded our knowledge of the complexity of reservoir sedimentation.
The engineering interest in reservoir sedimentation concerns three physical aspects; (i) overall volume of trapped sediment, (ii) distribution of deposit volume, and (iii) distribution of sediment particle size within the reservoir. The loss of storage capacity due to sediment deposits reduces the efficacy of a reservoir to regulate the flow and to provide a flood control. The distribution of volume of deposit determines the relative impact of trapped sediment on the usable storage, and the distribution of particle size effects the density of deposits as well as the potential damage caused by the ingress of sediment into the power inlets.
A number of approaches have been developed in the world to study these phenomenon. These include empirical methods; mathematical modeling and physical modeling but all these approaches have their limitations and need research and study to evaluate their effectiveness. Tarbela reservoir is one such place where ideal conditions exist to enhance our knowledge in area of sedimentation engineering.
WAPDA was established to develop the water and power resources of the country. It was structured as a multi-disciplinary organization with wide autonomy of working. It was at its Zenith when it most successfully and in record time completed world’s gigantic Indus Basin Project. Although, after the Indus Basin Project no new large construction project with the exception of SCARP was handled by WAPDA yet, it continued its effective and productive role of water development through research and studies. Between 1974 to1987 under its aegis world’s largest ever undertaken prototype research in the mechanics of alluvial channels using the canals and rivers of Pakistan was undertaken with the collaborative sponsorship and funding from the National Science Foundation of USA. The accomplishments under this research endeavor provided worldwide designers of the alluvial channels new approaches based on phenomenon hither to unknown and unobserved. Later, the WAPDA organization entrusted with this research project was elevated into an international sedimentation research institute in order to use its knowledge and expertise to research and study the complex processes of sedimentation, the biggest menace and threat to the water resources whether these are flowing or conserved.
Then a gradual apathy, unconcern and indifference on WAPDA’s part towards its basic objective of development of water and power resources tookover; most probably due to the attitude of its higher-ups who considered WAPDA’s role solely of a revenue collection agency. Unfortunately, those under the top brass were also insensitive towards the sophisticated expertise developed within the organization and therefore did not have the capability of properly guiding or counseling the decision-makers. The net result was that organizations that were built in decades were destroyed and reduced to shambles in months. The star international sedimentation research institute is now dumped into few katcha garages in a remote corner of the city. All its sophisticated equipment has either been reduced to junk or pilfered and all the expertise gained totally lost. This world renowned research institute is now headed by a Sr. Engr. who has been promoted from a mechanical overseer. Similarly, another organization, which was developed from Dams Investigation Circle (mentioned earlier), is under so much fear and harassment that its employees have practically lost all nerve. This organization is also being headed by a mechanical engineer who does not know even basics of dam engineering.
Various periodic inspections of Tarbela Dam by experts recommended different solutions to tackle the sedimentation problems of the reservoir. For testing and researching these solutions it was proposed that immediately a physical model studies laboratory be established at Tarbela site. This laboratory would not only undertake a comprehensive research and study to find solutions to Tarbela problems but also cater for future needs of other projects on the Indus River and its tributaries. In this regard collaborative efforts were made with a prestigious Chinese sedimentation research institute. But, with the departure of those who were instrumental in developing of this collaborative activity with the Chinese, every thing was thrown to airs. The Chinese are constructing a very large dam namely “Three Gorges Project”. This project is not only being researched in a physical-modeling laboratory at the site but at every major engineering university in the country. What a pity? We who claim to have world’s most integrated water resource and conveyance system do not have even one laboratory in the country capable of studying dams, reservoirs or sedimentation problems. On the other hand, as announced by the Chief Executive, we are planning to construct a number of reservoirs and, unfortunately, do not posses the basic infrastructure to study the complexities involved. The one laboratory at Nandipure under the Punjab Irrigation Department is not even sufficient to handle Punjab Irrigation’s own problems and the efficacy and efficiency of this laboratory portrays the same story of apathy.
WAPDA has now come up with its dream of “vision 2025”. With the present level of in-house knowledge and expertise can it even initiate such a utopic program? We talk of constructing projects like Bhasha Dam. Unfortunately, we think of Bhasha probably similar to a plaza. This project is going to be far more problematic than Tarbela (Refer Panel of Experts Report-1988). No local firm (s) is capable of undertaking its investigations without active collaboration of foreign experts/specialists. Had we continued the research and study efforts started way back within WAPDA, we by now would have achieved a level of knowledge whereby our dependency on foreign expertise had been minimal. But, we wasted all opportunities and chances. No we can do nothing but hold Namaz- e- Istasqa.