ISLAMABAD: Trap­p­ed sediment has robbed roughly 50,000 large dams worldwide of an estimated 13 to 19 per cent of their combined original storage capacity, and total losses will reach 23 to 28 per cent by 2050, latest UN research warns.

The global loss from original dam capacity foreseen by mid-century – from 6,300 billion to 4,650 billion metric cube in 2050.

UN University’s Canadian-based Institute for Water, Environment and Health applied previously-determined storage loss rates to large dams in 150 countries to forecast cumulative reservoir storage losses by country, region, and globally.

The United Kingdom, Panama, Ireland, Japan and Seychelles will experience the highest water storage losses by 2050 – between 35pc and 50pc of their original capacities – the study shows.

Asia’s 43 countries are home to 35,252 large dams, making it the world’s most heavily dammed region. The region is home to 60pc of the world’s population and water storage is crucial for sustaining water and food security.

The reservoir storage loss in Pakistan has been estimated to 7pc by up to 2022, 12pc by 2022-30, and 18pc by 2030-50.

In 2022, the region is estimated to have lost 13pc of its initial dam storage capacity.

Published in Dawn, January 12th, 2023