Barrage de La Tache, Granite dam in Renaison, France.

Barrage de La Tache is a granite dam located in Renaison that holds a large reservoir of water. The structure features massive granite walls that taper progressively from the foundation upward, creating a distinctive tapered profile.

The dam was constructed between 1888 and 1891 to supply drinking water to the city of Roanne in the Loire department. It was built during a period when water storage infrastructure became increasingly vital for urban development.

The dam takes its name from the La Tache site in Renaison. Its reservoir is used for fishing, with pike, carp and perch among the species found there. The structure stands as a landmark of late 19th-century water engineering in the Roanne area.

The dam lies in the commune of Renaison, in the Loire department, and the reservoir it holds can be seen from the surrounding roads. The crest is 221 m long and only 4 m wide, so the walkable top is narrow; the base spreads to 47.50 m. Access to the structure itself depends on the operator's inspection and maintenance work.

The dam's crest is only 4 m thick, while its base measures 47.50 m, giving the granite wall a pronounced batter. Behind it the reservoir holds 3,600,000 m³ of water, drawn since the 1890s for Roanne's drinking supply. The 221 m crest walk shows how the masonry narrows from valley floor to top.