In their latest exercise of 1994, WAPDA has tried to justify the construction of Kalabagh Dam by projecting that there will be loss of capacity in existing reservoirs by 2.91 MAF upto the year 2000, and that 3.6 MAF storage is required for assuring the water availability to provinces under the Water Accord, 1991. In other words, Kalabagh Dam will be a replacement dam requiring no additional water. In this context it may be pointed out that the Kalabagh dam project was conceived in the year 1975 and the revised documents was prepared in the year 1984, much before the Water Accord was signed in the year 1991. The design of Kalabagh Dam is therefore not based on the concept of the dam being a replacement dam. Surely the reservoir operation criteria and the economics of the dam will change drastically if it is to be considered entirely as a replacement dam.
As regards the contention of WAPDA that 3.6 MAF of water of Kalabagh Dam would be utilized for ensuring water availability to the provinces under the Water Accord, it may be stated that specific allocations have already been made to provinces under para 2 of the Accord. It is inconceivable that the Accord allocations for present projects can be made dependent on a controversial Kalabagh Dam expected to be constructed in future. It may also be pertinent to point out that this point to link the Water Accord allocations with future storages was raised by a province in the meeting of Council of Common Interests held on 16th September, 1991, but it was not accepted. It may further be stated that Water Accord allocations have been made knowing fully well that the allocated water would not be available all the time and this position has been taken care of in para 14(b) of Water Accord, which specially deals with the shortages and surpluses of water availability and it lays down that these are to be shared by the provinces on an all- Pakistan basis.
The linking of water allocations with future storage will create more complications. Under para 4 of Water Accord the surplus water from the future storages has to be shared in the ratio 37:37:12:14 for Punjab, Sindh, Balochistan and NWFP respectively, whereas if Kalabagh Dam is treated entirely as a replacement dam, as now suggested by WAPDA, the distribution of stored water would probably be in the same ratio as per allocations of existing projects under para 2 of the Accord. This will be a great loss to the smaller provinces, as the water allocations under para 2 of the Water Accord for the existing projects are in the ratio of 48.9:42.6:3.3:5.2 for Punjab, Sindh, Balochistan, and NWFP respectively. This will be a clear violation of specific provisions of the Water Accord.
Now let us examine the aspect of silting of reservoirs brought up by WAPDA as a justification for Kalabagh Dam. In this context, instead of raising this issue simply to justify Kalabagh Dam, WAPDA should have projected the complete picture as to what was the expected rate of siltation of each reservoir according to the original project feasibility report and what was the estimated life of each reservoir. Also what were the measures envisaged and being taken to reduce the incidence of siltation and their efficacy. Further it should also have been mentioned what remedial measures were envisaged for offsetting the effect of siltation and with what results.
As far as the life of the reservoirs is concerned, it was envisaged to be 55 and 75 years for Tarbella and Mangla respectively in the original projects, which has been revised to 125 and 225 years respectively due to lower rate of siltation than estimated. The rate of siltation will be further reduced as WAPDA has already initiated a large scale water shed management programme in the catchment areas of the reservoirs, though they have not published the results achieved. Moreover, by proper sluicing operations, the silt deposits of Tarbella dam can be flushed out as recommended by Chinese experts. WAPDA had made a study of siltation of reservoirs in 1988, in which, extent of siltation of the reservoirs was indicated to be 1.23 MAF and the annual rate of siltation of live storage was indicated to be 0.081 MAF for all three reservoirs. WAPDA has updated these studies in 1992-93 and some how or other tried to show higher rate of siltation, though it should have reduced consequent upon water shed management and silt exclusion operations. Adopting WAPDA's figure of 0.081 MAF of siltation per year, further loss of capacity will be only about 1 MAF more in the next 12-13 years from 1988 upto the year 2000.
There is an inbuilt provision in the design of Mangla dam for raising its height to increase its capacity to offset the effect of silting. In fact even in its present shape Mangla can store an additional 2 to 3 MAF of water, without any additional capital investment. The reasons put forward by WAPDA for not raising Mangla are that there is no enough water in Jehlum river and that the raising will be economical only after Mangla dam has silted by 50%. These reasons of WAPDA are flabbergasting. The water level in Mangla is being proposed to be raised to counter the effect of silting and not for storing additional water, so where is the question of availability of more water in Jehlum river for this purpose? WAPDA are proposing a costly Rs. 250 billion Kalabagh Dam to counter the effect of silting of Mangla reservoir, but refuse to raise the water level in existing Mangla dam till it has silted by 50%!
The above analysis shows that WAPDA has unnecessarily tried to link the issues of utilization of Water Accord allocation and silting of reservoirs with Kalabagh Dam.