LESSONS FROM JOSHIMATH: HIDDEN WATERS

Subsidence of the pilgrim town of Joshimath in Uttarakhand in early January this year, and a month later, a village in Doda district of Jammu and Kashmir, served to highlight a crucial factor – our poor understanding of the springs, aquifers, permafrost and rivers that weave through the Himalayan mountains.

The Himalayas are aptly described as the “water tower” of Asia, recognising the quantity of ice and glaciers they hold. However, while the other sources of water, primarily springs and aquifers, are taken for granted by the local populace, the policymakers are guilty of not focusing enough on them. These have often been the principal water source for people living in mountain regions.

Even as environmental experts and activists have been raising the alarm on the “hidden waters” for some time, the dying springs of Himalayas grabbed attention only recently. One of the reasons attributed to Joshimath’s subsidence is the tunnel for a hydropower project that had punctured an aquifer. This has led environmentalists to warn of the impact of development projects on, not just rock and soil, but on the precious water sources that criss-cross the mountains.

A holistic ecological view of the entire mountain-water system needs to be understood, the experts say, adding that understanding the science of soil in retaining moisture is crucial. As global temperatures rise, the warmer the air gets, the more water it can hold.

However, soil that has been drier for longer absorbs less water. Thus, climate change results in lower aquifer recharge, despite the higher amount of rainfall in the shorter, wetter, seasons.

This lack of understanding of deeper, or hidden, water also plays a great part in the damage done by hydropower projects. Run-of-the-river projects are defended as being “ecologically benign”. But they divert up to 95 per cent of the river water and their cemented tunnels do not let water seep into the soil. While this impacts the water needed to replenish aquifers, it also deprives the entire mountain eco-system of water, so vital to maintain green cover and stabilize hillsides.

Landslides and subsidence are an obvious outcome.