The construction of the Baells reservoir Historical milestone · Cercs, Berguedà, Barcelona Image of Cercs, not of the place itself. The Llobregat reservoir, completed in 1976, regulates the flow and supplies a good part of the Barcelona area. Its filling flooded inhabited settlements at the bottom of the valley and forced the Alt Berguedà road to be diverted. 1976 Photo: Unknown author (Public domain) What to see and do in Cercs