Reply affidavit on behalf of Secretary, Department of Water Resources, River Development and Ganga Rejuvenation, Ministry of Jal Shakti in the matter of news item titled "Ganges Brahmaputra basins to feel impact of climate change: Report" appearing in the Millennium Post dated March 21, 2024. The report was in response to the NGT order, June 22, 2024.

The news article talked about the alarming impact of climate change on South Asia's major river basins, including the Ganges, Indus and Brahmaputra. It was also mentioned that the indiscriminate discharge of sewage and industrial waste has severely polluted the water posing significant risks to both human health and the environment. It also said that the monsoon season, critical for replenishing water resources, now brings devastating floods while dry seasons worsen water scarcity.

The Ministry of Jal Shakti in November 15, 2024 had filed a reply affidavit which mentioned the project report on snow and glacier changes and their impacts on melt runoff in Himalayan basins prepared by the National Institute of Hydrology on March 2022. The concluding part of the report talked about the amplified hydrological impacts under higher emissions, with intensified rainfall events and accelerated glacier retreat driving future water availability. The report emphasized the urgent need for climate mitigation to prevent severe reductions in snow cover and to manage the increasing variability in water resources.

The Intergovernmental Panel on Climate Change (IPCC) assessment reports elaborated about the effect of temperature increase and glacier retreats in the Indian Himalayan basins. The study titled "Snow and glacier changes and their impacts on melt runoff in Himalayan basin" was conducted for research purpose for analyzing the climate change impacts on Himalayan basin and to test the applicability of spatial process in hydrology (SPHY) model for separating the different runoff components.

Baspa river is a major tributary of Satluj river and out of the total basin, around 18-20 per cent area is covered by glaciers and permanent snow covers. Therefore, the Baspa basin was selected to analyze the effect of snow and glacier changes and their impacts on melt runoff components. The glaciers showed a noticeable change in the glacier area in the Baspa basin.

The findings of the study showed that the contribution from glacier melt runoff has been found to reduce, while snow melt contribution has increased in past years due to changes in glacier and snow covers in the Baspa basin. In this study, the spatial process in hydrology (SPHY) model was explicitly tested to separate the snowmelt and glacier melt runoff contributions from the total runoff as previously the separation.

National Institute of Hydrology, Roorkee under the Centre for Cryosphere and Climate Change Studies has started working on different glaciers in Indian Himalayan regions such as Gangotri glaciers, Triloki glaciers and Milam glaciers to analyze the glacier changes and their impacts on melt runoff.