Flood in Pakistan

The intensity of the localized rainfall was fantastic – four months worth of rainfall had fallen in just a couple of days. Some areas in Northern Pakistan received more than three times their annual rainfall in a matter of 36 hours. Gushing quickly down the tributaries into the Indus River, the rainwaters gave rise to floods of catastrophic proportions. Given the immensity of the downpours, some flooding was inevitable. Yet rivers are essentially channels to drain out water; being one of the largest rivers of the world, the Indus should have been able to carry out the excess waters into the Arabian Sea which it joins near Karachi. Why could the river not flush out the excess waters? This is where human intervention – in terms of water resource planning and infrastructure development – played an important role in the floods.

To increase the area under irrigation in Pakistan, more and more of the waters of the Indus River have been diverted in recent decades into nearby farms. Many of these farms are owned by the richer farmers who have, with state support and over the years, built levees or embankments along the river to protect their farms from the occasional floods. It is not only the Pakistani government but local councils and water resource planning authorities in all the countries in South Asia which have supported such ‘straight-jacketing’ of rivers. Yet each human interference into a natural river system has its consequence: when excessive amounts of water are drawn out of its channel, a river channel becomes less efficient and loses its ability to quickly move the water. When levees are built along the banks, the sediments get deposited on the river bed, which gradually rises above the surrounding plains. Not only does this enhance the flood risk, the levees standing as walls also make it difficult for the floodwater to return back into the channel once it has spilled over.