Road Elevation Strategy for Vehicular Mobility under Kapila River Flash Flood Risks near Mallanamule Mutt of Nanjangud, India

Background: NH-766, a critical inter-state corridor in southern Karnataka, experiences recurrent flooding along a 1-km stretch near Mallanamule Mutt due to Kapila River overflows triggered by Kabini Dam releases. This repeated inundation disrupts commuter movement and industrial logistics, underscoring the need for targeted, flood-resilient road infrastructure interventions. Objective: The study aims to identify low-lying regions along the NH-766 near Mallanamule Mutt and assess the feasibility of raising the land and road surface to mitigate future flash flood impacts. Methods: Field visits were conducted to document flood conditions and identify the inundated 1-km road stretch through photographic evidence. Additionally, Google Earth Imagery was used to analyze ground conditions and flood extents during flashflood events recorded between 2017 and 2021. Results: Flooding of 3-5 ft occurred along the road section during Kabini Dam discharges as low as 50,000 cusecs, causing recurrent traffic disruption. Results show that elevating the road by at least 9 ft above observed flood levels along the 1-km stretch between South India Paper Mills Ltd and Mallanamule Mutt is the most cost-effective measure to ensure uninterrupted transport. Conclusion: Raising the road surface along the vulnerable stretch of NH-766 can significantly reduce future flood-related disruptions and enhance transport resilience. The findings provide a practical basis for policymakers and planners to formulate effective flood management and infrastructure adaptation strategies for sustainable inter-state connectivity.