The challenge In Himalayan sub-basins climate change and socioeconomic development put pressure on water resources which are vital for domestic use, industry, agriculture, electricity generation and the natural environment. Under these pressures, a business-as-usual approach is no longer suitable, and Indian authorities and wider stakeholders are calling for more integrated, inclusive, and transformative pathways for the basin`s future through sustainable surface water management.

Judicious allocation of water for various uses is crucial especially when future climate change projections show declining trend in water resources availability. This necessitates improved water management in the reservoirs by enhancing the decision-making capabilities of the relevant stakeholders from a climate change perspective.

The impact of climate change on glaciers has significant consequences on the downstream water availability. In central Himalayan River Basins, a large portion of streamflow contribution comes from monsoon rainfall during the summer season. However, during dry seasons, there is a significant input from snow and ice melt to the river discharge. Understanding the behavior of the Himalayan glaciers and their contribution to water supply is one of the major challenges for the scientific community. IWRM is crucial for stainable management of freshwater resources, addressing current and future demands for drinking, sanitation, agriculture, industrial, power generation and other uses, particularly in view of anticipated climate change impacts such as increased variability in seasonal rainfall and growing incidence of droughts and flash floods.

Our approach and interventions The Swiss support in surface water management refers to the SCA-Himalayas project through initiatives in Madhya Pradesh and in Uttarakhand. In Madhya Pradesh the project supported the water management of reservoir operations. A Climate Change-Decision Support System (CC-DSS) for Rani Avantibai Sagar (Bargi) Dam was developed to assess and optimize water availability through simulations combining different scenarios, adaptation measures and adjusting reservoir operation rules. The CC-DSS is based on various model interactions between climatic and hydrological parameters and considers requirements for water storage and supply for irrigation, industry and drinking and other uses such as flood control, power generation and navigation. The CC-DSS can simulate historical and future conditions, supporting planning and operation management of multi-purpose reservoirs. In addition, a Water balance modelling of Rani Avantibai Sagar (Bargi) Dam was carried out i) to estimate water demand for irrigation, domestic water, hydropower generation and commercial use, ii) to estimate water supply deriving from the reservoir and canals and iii) to assess the impact of surface and ground water management for various scenarios. A guideline document on water resources management for reservoir catchments using the CC-DSS was prepared and it was launched by the Water Resources Department, Government of Madhya Pradesh.

In Uttarakhand the Swiss supports focus on IWRM in Bhagirathi Basin to support planning process through glacio-hydrological modelling, water allocation modelling and the elaboration of an IWRM plan and a DSS: For the entire Bhagirathi Basin and for Din Gad catchment (covering Dokriani glacier) within Bhagirathi Basin, glacio-hydrological models – using the Spatial Processes in Hydrology (SPHY) model – were developed to assess the impact of climate change on glaciers, snow-melt, and runoff, and future water availability. The results of the glacio-hydrological model feed into a water allocation model WEAP (Water Evaluation and Planning) to analyze how different runoff components propagate in the larger sub-basin and to assess the impacts of climate change, socio-economic development and climate change adaptation measures for water supply and demand. The results in combination with contributions from state departments and local stakeholders are shaping the development of an IWRM plan

Collaboration with key partners The CC-DSS for the reservoir in Madhya Pradesh was developed with and for the Water Resources Management Department of the Government of Madhya Pradesh. The activities on IWRM are carried out in close collaboration with the nodal agency – State Environment Conservation and Climate Change Directorate of Uttarakhand. The technical implementation partners are FutureWaters and University of Utrecht from the Netherlands, University of Geneva, TERI and BOSS Webtech.