Identifying the cause of the auxiliary spillway chute failure at Toddbrook dam, UK

When the auxiliary spillway chute at the Toddbrook dam, UK, failed on 1 August 2019, 1500 people were evacuated downstream as a precaution. The dam had recently undergone a safety inspection, so an independent governmental inquiry panel was established to explore what had gone wrong and what lessons could be learned. The author was a member of the inquiry panel, charged with the specific task of identifying the cause of the failure. This paper explores the background to the work carried out and the reasoning behind the eventual conclusions.