The 1983 Spanish floods were a natural disaster that occurred between 26 and 27 August 1983 in northern Spain, particularly in the Biscay region, where the Aste Nagusia – the Bilbao city festival – had been taking place. The flood resulted in significant damage to property and caused the deaths of 34 people, with another five unaccounted for. The flood led to preventive measures being put in place and the redevelopment of Bilbao's riverside.