The challenge Flash floods refer to flood events that occur within a short time frame and are often associated with cloudbursts particularly during monsoon season or also by GLOFs. With the effects of climate such events tend to increase in intensity and frequency. Due to the short time frame such events are difficult to predict, and can be highly destructive in the mountainous context due to mobilized material such as stones, trees, rubble etc.

In Himachal Pradesh, in Kullu district at least 66 floods have occurred since 1965. Also, Uttarakhand and neighbouring states reported massive losses in 2010 and 2013 due to floods, flash floods, landslides and cloudburst events. Such incidents affected disproportionately the socially and economically disadvantaged and marginalized people. With the expansion of settlements there is an increasing number of buildings and public infrastructure (e.g., schools, hotels, roads and hydropower projects) which are constructed in hazard-exposed areas.

Our approach and interventions SDC’s interventions related to management of flash floods mainly focus on Kullu district in Himachal Pradesh. This area has been identified as one of the most exposed and vulnerable areas in the frame of the projects IHCAP and SCA-Himalayas. The following activities have been carried out:

• General assessments of floods, GLOFs, landslides, snow avalanches
• GLOF risk assessment on houses, roads and agricultural land at tehsil level of Himachal Pradesh
• Analysis of flood events and gauge stations (concluding that 70% of infrastructure elements are in high to very high flood risk zones).
• Preliminary early warning system (EWS) design for Parvati Valley considering three hotspots
• Detailed project report (DPR) entitled “Reducing Glacial outburst and flood risk in Parvati Valley” with the following key components: Monitoring and field studies, GLOFs and flood hazard zonation, participatory vulnerability mapping, EWS development, capacity building, integration to a district Disaster management Plan, monitoring and experience capitalization.
• In 2022/23 the DPR has been amended by the following elements: Extension of baseline data (incl. recent flood events), estimation of regional flood quartiles, GIS-based modelling and hydraulic modelling, creation of a database with infrastructure assets at risk.

These results are summarized in the following documents:

• Synthesis Report: Climate Vulnerability,
• Hazards and Risk: An Integrated Pilot Study in Kullu District, Himachal Pradesh
• Science brief: Flood risk and early warning systems
• DPR: Reducing glacial outburst and flood risk in Parvati Valley

Collaboration with key partners The assessments and modelling were done by a Swiss organizations (Geotest, University of Geneva, University of Zurich). The DPR was elaborated in close collaboration with the Indian partner CTRAN. The initiatives in Himachal Pradesh were done in close collaboration with the state government of Himachal Pradesh, namely the State Council for Science, Technology and Environment (SCST&E).