India’s river interlinking projects are changing monsoon patterns, may worsen water stress: study

For four decades now, India has put its weight behind river interlinking projects that transfer excess water from one river basin to the other — a $168 billion answer to a swelling water stress crisis. A new study published in Nature Communications, however, challenges these claims: many hydro-linking projects in India and globally are altering monsoon cycles, disturbing complex hydro-meteorological systems, which in turn “may worsen the water stress across the country, making the interlinking projects ineffective or possibly even counterproductive,” it says. The logic behind inter-basin water transfers tracks with mathematical concepts of surplus and deficit: excess water is routed from “donor river basins” to “recipient” dry regions ; if a maximum of water is kept on land, and does not flow into the Arabian Sea or Bay of Bengal, India’s growing water demand could be met. However, the study questions the merit of these claims, arguing that reduced precipitation “can dry rivers post-monsoon, augmenting water stress across the country and rendering interlinking dysfunctional.” Activists and environmental experts have advocated for policymakers to evaluate the impact — how groundwater, land-atmosphere feedback, local ecosystems, monsoon patterns respond to inter-basin water transfers or other projects that alter the natural flow of rivers.