Explain the concept of 'peak water' and discuss its implications for India's water and food security.

'Peak water' is the point at which river flow, temporarily swollen by accelerated glacier melt, stops rising and begins an irreversible decline. ICIMOD's HI-WISE assessment projects that water availability in the Hindu Kush Himalaya will peak around mid-century and then fall [1] — making today's apparent abundance a deceptive prelude to scarcity for India.

Understanding the concept

• Two phases: warming first pushes melt-fed discharge above normal; once the ice store shrinks past a threshold, flows decline permanently. On current emissions pathways 80% of HKH glacier volume could be lost by 2100 [1].
• Unlike drought, the loss is of a stored buffer, not of rainfall — hence irreversible on human timescales.
• The rising limb is also the hazard limb: surplus meltwater fills moraine-dammed lakes. The Central Water Commission monitors 902 glacial lakes, and Wadia Institute inventories list 1,266 lakes in Uttarakhand (2015) and 958 in Himachal Pradesh (2018) [2].

Implications for water security

• The Indus, Ganga and Brahmaputra contain the bulk of the region's glaciers, and about 1.65 billion people downstream depend on these flows [1].
• Melt matters most in the lean pre-monsoon season; a post-peak decline cuts precisely the dry-season flow that drinking water and hydropower firm capacity rely on.
• Dams and canal commands are 50–100-year assets being sized on a temporary meltwater bulge, risking stranded capacity.
• Being transboundary, altered flows raise sharing frictions with upstream and co-riparian states [1].

Implications for food security

• Indus-Gangetic rabi irrigation draws on lean-season flow; its contraction threatens the cropping calendar of India's grain heartland.
• Reduced flows and droughts are projected to jeopardise food, water and livelihood security, in a region where one-third are already food insecure [3].
• GLOFs episodically destroy terraced farmland, silt canals and displace mountain cultivators.

Peak water thus converts a climate signal into an agricultural and fiscal risk. Strengthening the National Mission for Sustaining the Himalayan Ecosystem [4], scaling the National GLOF Risk Mitigation Project beyond its four pilot states [2], curbing black carbon, and building storage and micro-irrigation can turn the pre-peak decades into an adaptation window — advancing SDG-6 and SDG-13 together.