Today, water is the most valuable commodity on earth as compared to other natural resources; while oil, for instance, could be replaced by other sources of energy, there is no substitute for water .
It is the most widely distributed substance on the planet; about three-fourth of it contains water . Only 2.53 percent of it is freshwater, while the rest is salt. Out of the world’s total freshwater resources, about two-thirds is locked up in ice caps and glaciers. So, whatever amount is available for human consumption, it is drawn from lakes, rivers, aquifers (groundwater) and rainfall runoffs.
Water is a necessary ingredient for the survival of civilisation, as for one thing, it is for agricultural development. Imagine the amount of water required to sustain a world of seven billion people. This means that the basic use of water is for the production of food.
According to the UN Food and Agriculture Organisation (FAO), “agriculture is the largest user of water in all regions of the world, except Europe and North America.” Out of the total, nearly 70 percent of water is consumed for food production, 20 percent for industry and 10 percent for domestic use. For example, water required to produce food  amounts to 2,000-5,000 litres per person per day; whereas, for the basic human needs including drinking, only four litres per day is needed.
More so, the preference for a higher tier on the food pyramid by the privileged few entails an extravagant use of water and energy resources. It takes 13,600 metric tons (15,000 US tons) of water to produce a ton of beef in comparison to only 900 metric tons (1,000 US tons) for one ton of grain to be produced (c.f. Professor William T. Pennington and Cech), stressing the need for food habits to be grossly tailored to meet the available water and human needs.
Of the total water available in Pakistan, 96 percent is used for agriculture. While the quantity of water for Rabi crops like wheat fell below the much needed 34 MAF after the 2010 floods, according to some estimates, starting July 26 that year, 1,400,000 cusecs of water crossed Sukkur - the highest level ever during the last 66 years of independence. Consequently, drinking water for humans and livestock became scarce, which reminded one of the quote:“ Water , water everywhere, but not a drop to drink.”
According to an estimate, some 800,000 cusecs of water on the average flow through the Sukkur Barrage en route to the Arabian Sea. Since the first wave of the floods, 95.4 MAF,  flowed to the sea vis-à-vis 34 MAF, an amount equivalent to the storage capacity of five Kalabagh dams  discharged annually to the sea. According to a report, the Water Apportionment Accord 1991, however, envisaged a release of 10 MAF for the Indus Delta.
While public concern about ravages of floods looms large, the fear of droughts due to severe lack of water reservoirs in Pakistan cannot be overemphasised. But for the idea of small dams and diversion projects advocated by experts (Dr Zafar Altaf and Dr Zakir Hussain) over the years, if the aerial seeding of forest lands initiated by President Ayub Khan had been carried on, it could have made a significant difference to the problems of water and energy shortages in the country.
Besides this, while India continues to construct hydro projects on Chenab and  Jhelum rivers, Pakistan is not taking up the Kalabagh Dam project despite the fact that it was agreed and approved more than 60 years ago; what to talk  about the importance of small dams (mill dams)  and the acute shortage of water faced by the country, in the wake of recurrent floods and climate change.
With population and global warming on the increase a big decline in the world’s water supplies is expected in coming years (World Water Development Report 2008), Pakistan would have a difficult time without large reservoirs like Kalabagh Dam.
The writers are ex-director NIAB and professor of Environmental Science, GCUF, and lecturer respectively.