Rivers water dispute-II
Harvest of problems
A A Musalman
In the post Liaquat Ali Khan era India not only illegally doubled the storage capacity of Bhakra Dam but also started work on Nangal Dam and the Rajesthan Canal that would take Indus Basin waters outside it. The ruling coterie of Pakistan comprising the 'gang of four' was too busy in cutting the Bengalis to size to pay any attention to this blatant usurpation of Pakistan's sovereign waters and instead of confronting India appointed a Dams' Commission to find alternatives sources as promised by Ghulam Muhammad in 1948 who in the mean time become the Governor General having escaped imminent dismissal as finance minister in 1951 because of Liaquat's assassination. Dam sites at Mangla on Jhelum and Durband, Tarbela and Kalabagh on Indus were investigated among many others.
It must be noted the flow in IRS at that time was 160 MAF with India already appropriating illegally more than 3 MAF of Pakistan's waters through the enlarged Bhakra Dam. The Mangla site on Jhelum was found to be most suitable and was approved for construction of a dam by government of Pakistan in 1953. Of the three sites on Indus as mentioned, Tarbela site was preferred.
In the meantime the World Bank was pressing Pakistan to reach some compromise on the water disputes with India and refused any financial assistance for construction of Mangla Dam until all disputes on Indus Basin Waters were resolved. The then government of Pakistan agreed to the suggestion and after prolonged engineering studies carried out by World Bank Consultants a proposal was made out in 1956 to allocate all waters of three eastern rivers to India and those of three western rivers to Pakistan thereby depriving Pakistan its legitimate, and legal share of 21 MAF of waters of eastern rivers. The loss of these waters was to be compensated from transfer of waters from the western rivers on which India could not lay claims by any means.
It was suggested that the entire cost of all works to affect this transfer of waters shall be borne by World Bank, a consortium of some western countries and India with Pakistan footing only a small percent of total as a loan. It must be recorded to the credit of bureaucrats of those time that they continued to resist this anti-Pakistan proposal until a 'usurper', blinded by the dangle of dollars, showed them the door and agreed to sign in 1960 the treaty known as Indus Basin Waters Treaty through which 21 MAF or nearly 18 percent of Pakistan's total surface natural water resources were sold for 900 million dollars thereby 'truncating' most of Pakistan's agricultural potential for all time to come. An unpardonable crime indeed.
According to the said Treaty Pakistan is entitled to 142 MAF (Indus 93, Jhelum 23 and Chenab 26) of mean flow on the basis of 50 years' record at rim stations of Attock on Indus, Mangla on Jhelum and Marala on Chenab as these rivers enter the Indus plain. From these points onwards Indus travels nearly 750 miles to fall into the sea, Jhelum travels 190 miles to join Chenab and Chenab travels 370 miles to join Indus at Mithankot. For nearly 180 miles the combined flow of Jhelum and Chenab travel from just below Jhang to join Indus which travels a further 75 miles to enter the province of Sindh upstream of Guddu Barrage and then flows for another 370 miles crossing first Sukkur Barrage and then Kotri Barrage in the province to fall into the sea. The barrages on Indus in the Punjab are Jinnah (just down stream of the proposed site of Kalabagh Dam), Chashma and Taunsa. Now when these rivers travel mentioned distances they suffer losses due to evaporation from water surface, seepage through banks and percolation through beds. Total losses from these sources have been worked out as 16 MAF annually with 9 MAF in Punjab above Guddu Barrage and 7 MAF in highly arid zone of Sindh above Kotri Barrage which means that net usable flow in the rivers of IRS totals about 126 MAF annually. It is most important to note that in addition to the total flow it is equally important to see as to how this total flow is spread over a year. Nearly 59 percent of the net total flow or 75 MAF takes place in the flood season of June, July and August during which water is not required for sowing rabi or kharif crops. Total flow from September to December (rabi sowing) is 18 MAF and from January to May (Kharif sowings) 23 MAF as the average of the recorded flows which have varied to a maximum of 16 percent on the down side during the recorded period of time. According to records the minimum net flow in the IRS has been about 106 MAF. The cycle of these minimum flows averages five years. Theoretically, therefore, over 100 MAF can be taken away from the IRS for irrigation purposes. In any case rivers cannot be allowed to run dry for a variety of other vital reasons the central being the flood irrigation (sailabi land), marine life and the prevention of ingress of sea into the lands of the river delta. It is the last one which determines a minimum outflow into the sea which will also cater for other requirements. There is irreconcilable disagreement in this case between irrigation experts of Sindh and Punjab. While Sindh experts describe a minimum of 18 MAF outflow to cater for the marine life, mangroves and prevention of the ingress of seawater into delta, the experts from Punjab only talk of building a wall to prevent ingress of the sea. They do not say any thing about the requirements of preserving marine life and the mangroves below Kotri Barrage. The argument always becomes sour instead of being rational. What is most surprising is that these experts never talk of preventing staggering waste of irrigation water in the canal system and its distributaries. The experts of Punjab , as also its politicians and press, are only obsessed with the idea of building Kalabagh Dam with intellectuals like Hanif Ramay (Punjab ka Muqadma) saying that this dam should be built simply because no dam has been built in Punjab! The problem can be examined from the other side of the picture of existing irrigation system .
From all available published data more than 40 percent water taken into canals from the rivers at the barrages (no canal directly takes off from Tarbela or Mangla Dams) is lost before it reaches the fields. The reasons are again the same as in the case of rivers that is evaporation, percolation through banks and seepage through beds. In addition inadequate desilting of canals and distributaries narrows the cross section thereby badly affecting flow conditions resulting in reduced quantities causing scarcity at the tail ends of the system. The reduced velocity of flow, below self-cleansing, aggravates the situation over a period of time and also aids percolation and seepage which has turned millions of acres of land saline and water-logged over a period of time and continues to do so. The strident bhal safae effort of the army will ease somewhat the situation at tail ends but it is something which should be regularly done with diligence by the Irrigation Department.
According to latest available figures a total of 108 MAF was made available to all provinces in 1998-99 at the canal heads. Of this only 63 MAF actually reached the fields the rest being lost due to stated reasons. Imagine that the lost quantity of water in transit through the existing irrigation network is about seven times the storage capacity of the proposed Kalabagh dam. Only if one-fifth of water lost in canal system is retrieved it will not only obviate the necessity of building Kalabagh Dam but will also provide long term substitute to the depleting capacities of Tarbela and Mangla Dams. And this can be achieved by progressively lining the banks and beds of only distributaries and watercourses of the existing irrigation network. The process will involve trimming these water channels of small cross-sections first to the correct shape and then line their banks and beds with precast concrete blocks. The estimated cost is about one-tenth of proposed Kalabagh Dam and will take only one-third of the time. The remaining system of minor and major canals in the system can be lined over a long span of time eventually retrieving around 34 MAF of the lost water. This will also relieve the recurring problem of salinity and water logging. Just look back at the salutary effects of the lined canal of the Kotri Barrage. Pakistan is already groaning under a foreign debt of over 30 billion dollars. It will simply go insolvent if another 7 billion dollar estimated cost of Kalabagh is added just for the sake of fancies and obscurantism.
As far as the 3,000 MW hydel power capacity of the proposed Kalabagh is concerned it is important to consider two aspects. Firstly the over 3,000 MW capacity IPPs thrust over the people of Pakistan at the cost of perhaps the highest electricity rates in the world and secondly the sensitivity of hydel power generation to varying river flows during different seasons . With the IPPs already strung around the necks of the people there is no need to augment power resources for another decade especially when the transmission and distribution networks are inadequate to carry the increases that have already taken place. Both Tarbela and Mangla are rated at some 63 percent Installed capacity because of very high variation in river flows during a year. For Kalagabh this rating is about 45 percent due to its location much below the Indus Gorge. Only recently the depletion in reservoir levels due to smaller inflows has been adversely affecting power generation. With Kalabagh having no utility as irrigation storage for reasons already mentioned, there is no point to build it where it is for hydel power purposes for which far more suitable places are located in the Indus Gorge upstream of the Tarbela Dam where the river falls much more rapidly. It will be highly economical to build Power Houses in this 'Gorge' based on the principle of the run of the river that does not require construction of highly expensive storage reservoirs (dams). Obduracy must be shunned in national affairs.
The writer is a retired chief engineer