Implementation of an integrated approach for the diagnosis of river weirs: study of the Cère, Jordanne and Authre rivers in the Cantal region

Abstract

This paper describes the integrated approach used for inspecting small weirs on three rivers in the department of Cantal. They were small, low-drop weirs (1 to 4 meters), most of them stone masonry constructions. These weirs, some several hundreds of years old, were constructed for field irrigation or to supply water for mills. Due to lack of maintenance they are now deteriorating at an alarming rate after successive river flooding. The local authorities were concerned about the situation and called for a study of all the weirs. Over and above the simple civil engineering inspection required at the start of the analysis, considerations undertaken finally incorporated the various hydraulic, hydrobiological and heritage aspects surrounding the existence and operation of the weirs. The study established a hierarchy of priority classes for work to be done, which, together with a multi-criteria analysis, led to the establishment of a programme for renovating the 20 most critical of the total of 160 weirs.