The Indus basin which has sustained civilizations across millennia, presents new challenges to the people and states of the region. The way these challenges are addressed will shape the economic future of the people who share the Indus waters. Let us identify on the basis of the latest evidence, the nature of the water problem at hand.
Three hard facts have emerged: First, the per capita annual water availability in the Indus Basin has declined from 5,121 cubic meters in 1962 to 1,396 cubic meters in 2011. Given the fact that the internationally recognized minimum water requirement per capita per year is 1700 cubic meters, the current water availability in the Indus Basin is substantially below the minimum requirement level. The total annual river flow of the Indus Basin has declined from 119 million acre feet in 1960 to 113 million acre feet (MAF) in 1997. The rate of decline accelerated in the subsequent period of 1998 to 2011 with the annual flow of rivers in the Indus Basin falling to 102 MAF by 2011. In the case of Chenab the average annual flow has declined by 12 percent over the period 1960 to 2011 while in the river Jhelum it has declined by 17 percent. The decline in river flows could quite possibly be due to the lower precipitation in Jammu-Kashmir and Himachal Pradesh which constitute the water shed region of these two rivers. However careful research is required to quantify the various factors explaining the rather sharp decline in the river flows of the Indus Basin. In any case the declining river flows and increased seasonal fluctuations in these flows create the imperative for Pakistan to improve its water management and increase water use efficiency. At the same time collaborative efforts by India and Pakistan for forestation and management of the water sheds could slow down the increased sedimentation of rivers which reduces the life of dams downriver. Reforestation in the water shed could also prevent devastating flash floods downstream during heavy downpours in the catchment areas.
Second, the monsoons have shifted from the eastern part to the western part of what is Pakistan today while the timing is delayed compared to the past. At the same time there is reduced glacial melt in August a month in which glacial melt historically was high. The increased variability in the timing and location of monsoons as well as the change in the temporal pattern of glacial melt will further accentuate the observed shortages of water in the Indus Basin during planting seasons. It is therefore crucial for the people and government of Pakistan to realize the fact that Pakistan has shifted from being a water surplus to a water scarce country and this scarcity is likely to get worse in the decades ahead. This has urgent implications for policy and public action to improve the irrigation efficiency as well as the water use efficiency.
At the moment out of every 100 million acre feet of water pulled out from the rivers for irrigation, 63 million acre feet are lost during transportation before the water reaches the farm gate. It is necessary therefore to line canals wherever possible and to construct concrete water courses. The application of water on the farms is also highly inefficient due to lack of land leveling, and wastage of water during its flow to the root zone of the crop. An institutional framework for incentivizing farmers to improve on farm water management is required. The actions to be incentivized and supported through extension services are the use of laser leveling, drip irrigation and replenishing the organic matter in the top soil so as to reduce the water requirement per acre. It may also be worth considering a change in the cropping pattern towards less water intensive crops.
The third important dimension of water scarcity is the imperative to improve the extremely low water use efficiency in the Indus Basin. In the case of the top five food producers in the world (Brazil, China, France, Mexico and USA) the water use efficiency is USD 23.8 per cubic meter of water used. In the case of the Indus Basin, water use efficiency is as low as USD 3.34. This suggests the need to devote greater farm area to high value added farm products such as fruits, vegetables, flowers, inland fisheries, livestock and dairy products.
Facing the challenge of water shortage in the Indus Basin requires new initiatives in public policy and inter-state co operation.