Designed in 1880 by the chief engineer of the Ponts-et-Chaussées Édouard Caméré and inaugurated in 1887, the Poses-Amfreville dam (Eure) is above all the first navigation dam after the river estuary subject to the influence of the tides. With a length of 235 metres, it has 7 passes of about 30 metres and its head varies between eight and one metre. The dam links the two banks of the Seine via the pedestrian bridge. It consists of a dam and two locks: one 220 m long and the other 140 m long.)
In 1990 a hydroelectric power station was built to exploit the head of the dam. It is attached to the dam on the left bank and is equipped with 4 vertical axis turbines representing an installed power of 8 MW. It was inaugurated in 1992.
The hydroelectric power station is equipped with a fish pass to ensure the free movement of fish, and thus to cross the dam.
The dam and its locks were built between 1878 and 1881. The dam is of the movable spillway type, with the water passing over the movable structure. It consists of steel beams and concrete cladding. It was developed by the chief engineer of bridges and roads, Edouard Caméré, and built under the direction of engineer Clerc. It was inaugurated on 3 July 1887. At the time, it was the dam with the highest reservoir (5.35 m) and the highest waterfall (4 m). It raised the level of the Seine by almost 1.20 m upstream of the dam. During the construction work, the confluence of the Andelle River was moved about 100 metres downstream.