This is a talk that was given at the Tyndall Centre in October 2018. It talks about the Western Cape Water Supply System (WCWSS) specifically covering the reconciliation of supply and requirement. The presentation also covered the 2015-17 drought, three of the driest years since 1951, exploring the progressive depletion of storage and demand management. The talk also covers how day zero was avoided, supply augmentation, irrigation supply and domestic response in CapeTown.