This commentary paper examines our local expert engagement methodology that we developed to understand water supply issues as well as to inform the direction of our action research conducted in Dhulikhel, a small town in Nepal. Through three years of field-based research at Dhulikhel, our inquiry uncovered a range of data ‘gaps’ and emergent as well as long-term conflicts around increasingly scarce water resources. To respond to this gap and contribute to inclusive water management, we developed and used a local expert engagement method, through which we were able to pool and mobilise a rich repertoire of hybrid knowledge from a range of local experts in Dhulikhel and others from nearby towns. The method of expert engagement was simultaneously linked to deliberations among local water stakeholders concerned with water supply management. Based on the lessons from this work, we argue that rich local expertise exists in water management and policy in Nepal, one that transcends the dichotomy between indigenous and scientific knowledge. We also show that as formal scientific knowledge becomes hybridised in different ways, this creates an important and actionable opportunity for advancing local science-policy processes to support water security agendas across the country.