Flood prevention methods.

Pakistan estimates the total losses from its recent floods in 2022 could be as high as $40 billion, affecting millions and killing more than 1,730 since mid-June.

Pakistan has about 145 million acre-feet (MAF) of water per annum, out of which, freshwater losses per annum to the sea in the form of floods is about 30MAF, about 15-20 per cent of annual water production in the Indus basin.

Groundwater accounts for more than half of all irrigation requirements, but there is clear evidence that groundwater is being over-exploited through about more than one million Tubewells, according to a 2005 World Bank Report.

The cost of installing tubewells in areas where the water-table depth is more than 24 meters is seven times higher compared to those areas where the water-table depth is around six metres, and the same is true with the increase of energy consumption for groundwater exploitation.

Canals can be constructed to divert floodwaters to rivers that can accommodate surplus flows, increasing groundwater levels as well as irrigable areas

A feasible, sustainable solution is the underground conservation of flood waters of the Indus Basin, improving the quality of water as well as its quantity. Of course, we need floods, monsoons and glacial meltwater supply because our whole irrigation system depends upon it for irrigation, especially sailaba, or runoff farming, among the oldest forms of irrigated agriculture.

But Pakistan needs 'safe' floods that do not produce disasters downstream. One methodology that can be adopted is to define safer flood peaks at different barrages of all our main rivers and, if needed, go for new barrages.

Floodwater diversion canal sites can be selected with the help of remote sensing geographic information systems using topography, soil strata and geology data. Using the flow of gravity, these sites can divert disastrous flood waters for maximum groundwater water recharge.

On the basis of present and past surface water data, modelling should be done to divert disastrous flood water optimally from rivers such as Indus and Chenab to accommodating ones such as Jhelum, Ravi, Satluj, and Beas.

According to the Pakistan Council of Research in Water Resources, as a result of the Indus Water Treaty, Pakistan successfully completed the gigantic project of Indus Basin Replacement Works. It was the biggest irrigation project (Rs124bn) in the world at that time, completed within ten years. Through this project...