Ouvrages du Libron, Hydraulic structure on Canal du Midi in Vias, France

Ouvrages du Libron is a fixed sluice-gate structure where the Libron River crosses the Canal du Midi at Vias, near Agde. The riverbed splits into two channels, each crossing the canal through six gates opening into six sluice bodies, with a protected area 30.5 m long between them. Each sluice is formed of three wall sections, and the sluice beds lie almost level with the canal's surface.

Engineer Urbain Maguès designed this structure in 1855 to replace an older pontoon system. It represented an important step forward in French water engineering of that era.

The Libron's bed was split into two channels so each could be crossed separately, letting a boat wait in the 30.5-metre protected area between them while the nearer channel was closed. The six sliding gates and stone sluice walls of 1855 still stand beside the canal, and the river's flash floods of up to twenty a year remain the reason for the arrangement.

The works stand where the Libron meets the Canal du Midi at Vias, near Agde. The river bed splits into two channels, each crossing the canal through six gates around a protected area 30.5 m long. The stone bridge with its rounded arches and dark metal railing carries the towpath over the structure.

The Libron's bed was lowered to almost the level of the canal's surface, so the sluice floors lie nearly flush with the water. The river is split into two channels, each crossing through six gates and six sluice bodies, with a protected area 30.5 m long between them. A boat waits while the channel ahead is closed, then crosses.