Causes and impact of the 2081 Flood of Sunkoshi River in Khurkot, Golanjor Rural Municipality, Sindhuli, Nepal

Abstract

Nepal’s steep topography and monsoon-dominated climate make it highly vulnerable to floods and flash floods. In 2081 B.S., a catastrophic flash flood struck Khurkot, at the confluence of the Sunkoshi and Tamakoshi rivers in Golanjor Rural Municipality, Sindhuli, and affected more than 500 families. This study was done to find the natural and human-induced causes of the flood, its socio-economic, infrastructural and environmental impacts, and ways to reduce future risk. A mixed-methods design was used. A household questionnaire survey was carried out with 150 respondents, and 19 problems associated with the flood, together with their causes, effects and mitigation measures, were ranked using the Relative Importance Index (RII). Field observation, a focus group discussion with community members and an in-depth interview with a technical expert of the rural municipality were also carried out. The results show that the biggest problem is weak coordination in disaster response and relief distribution (RII 0.88), followed by destruction of roads and transportation network (RII 0.87), loss of agricultural land and crops (RII 0.86) and riverbank erosion causing land loss (RII 0.85), while illegal riverbed extraction was ranked lowest (RII 0.71). The strongest cause of weak coordination was the absence of a clear inter-agency command and communication protocol (RII 0.83). Heavy monsoon rainfall, uncontrolled extraction of sand and gravel, removal of riverbank vegetation and inadequate flood protection structures were found to be important causes behind many of the impacts. Field observation showed that nearly 90 percent of the cultivated land in the affected belt was inundated, buried or swept away. The study suggests a single disaster coordination authority, stronger embankments and flood-resilient roads and bridges, better drainage, regulation of riverbed extraction, riverbank bioengineering, and an early warning system with community preparedness training.