 Construction commenced in 1959 , and the power station was opened by Queen Elizabeth II on 15 October 1965 . The concept was designed by Sir Edward MacColl , who died before it opened . The civil engineering works of the scheme were by James Williamson & Partners of Glasgow , and the main project contractors were William Tawse of Aberdeen and Edmund Nuttall of Camberley . Consultant electrical engineers were Merz & McLellan of Newcastle on Tyne . At the peak of the construction , there were around 4 @,@ 000 people working on the project . Thirty @-@ six men died in the construction of the power station and dam , and the cost of the scheme was GB £ 24 @.@ 5 million . 
