Pakistan is often characterized these days as a ‘water scarce’ country. But is this really true? Or are there other factors at work which have led to the illusion of scarcity? This is a case where the numbers tell the story. And there will be plenty to come. So be warned.

But first some history: The Indus Water Treaty was signed by Jawaharlal Nehru and Ayub Khan in Karachi in 1960. Of the six rivers which flow into Pakistan the treaty ceded use of the waters of the three eastern rivers - Sutlej, Beas and Ravi - to India. The waters of the three western rivers - Jhelum, Chenab and Indus - were given to Pakistan.

Prior to the treaty the total average annual volume of water flowing into Pakistan was 170 million acre feet - usually abbreviated as MAF. This is a measure of volume and one MAF is roughly equivalent to 1.23 billion cubic meters of water.

After the treaty, India invoked its right to use the waters of the three eastern rivers and launched an aggressive program of dam building. And now these rivers, by the time they enter Pakistan, are dry. In the process Pakistan has lost some 30 MAF of water per year of the 170 MAF which flowed to us before the treaty.

Hence our annual water availability is now on average about 140 MAF which flows to us through the three western rivers. In good years, when there is a lot of rainfall, this rises to 180 MAF. In drier years it can be as low as 110 MAF.

Now lets turn to how much water we use. The combined capacity of our system of barrages and canals is about 105 MAF. So, on average of the 140 MAF we get we dump about 35 MAF of water into the Arabian Sea every year. Of this about 30 MAF can easily be saved because at least 5 MAF is needed to maintain river system integrity downstream of the Kotri barrage. In other words we needlessly throw away about 20% of the water that flows into Pakistan every year.

The sensible thing would of course be to somehow save this water rather than than dump it into the sea. This is where the argument for big dams begins. The Kalabagh dam for example would have a storage capacity about 6 MAF. Make several such dams and you can store almost all the excess water that now flows into the sea. In fact the topography of the Skardu valley is such that a single dam there would store an astounding 25 MAF.

So if we are throwing millions of acre feet of water into the sea every year why is there talk of scarcity? Over the past few years the ‘tail ends’ of canals in Sindh are not receiving enough water. As a consequence many farmers in these areas are suffering. Verdant mango orchards have been destroyed and cash crops can no longer be grown. The perception is that not enough water is being supplied.

Let’s look at some more numbers: The total acreage under cultivation in Sindh and Punjab is roughly 20 million hectares. Of this 5 million hectares are in Sindh and 15 million in Punjab. Yet the water supplied into the Sindh canal system is 40 MAF while that supplied to Punjab is 54 MAF. Were this to be distributed in proportion to arable land the corresponding numbers would be respectively 24 MAF to Sindh and 71 MAF to Punjab. So if anything Sindh is receiving more than a proportionate share of water.

Why then the dry tail ends? This is politics at work. Powerful landlords upstream of the canals use their influence to tap into a much larger share of water than they are due or need. Farmers at the tail ends of the canals do not get their fair share.

The natural question is: Why do the Punjabi landlords not do the same as their Sindhi brethren and take more than their fair share of water? Well, they would if they could. They are of no better moral fiber. But the problem is that they are not as politically powerful as the Sindhi landlords who, for generations, have successfully managed to suppress their people by denying them basic rights and education. And so continue to maintain a stranglehold on political power which lets them do as they choose.

It is clear that in fact there is no scarcity of water. There is a surplus. But nevertheless we would do well to build the dams and reservoirs needed to store this surplus. There are many reasons to do so. Upstream storage would allow us to release needed water during droughts.

In years of heavy rainfall - when inflows rise to 180 MAF - the excess flows could be stored rather than raging through the floodplains of Sindh and Punjab causing immense damage to life and property.

And finally we could generate hydropower. Various studies over the years have concluded that the hydropower potential of the Pakistani river systems is of the order of 100,000 megawatts. Even if we were to do half of this we would have enough to meet our own needs and export some 30,000 megawatts to our neighbours.