In this study, HARC was able to collate information not previously considered (e.g. photos, recollections from on-site engineers). And applied our experience in dam break modelling and consequence assessments to update the potential loss of life (PLL) estimates. The output of the project removed the need for North East Water to undertake a planned, expensive upgrade of McCall Say Dam, and provided a new direction on how to minimise the societal and individual risk posed by the dam.