Canoe and kayak passes
Flat-bottomed slides made of concrete or polythene
A flat-bottomed slide has an aspect of play in it as it is a real aquatic slide. The main difficulty for the concept is the right positioning in the river. In fact, the downstream water outlet must be 40 to 50 cm lower than the level of the entrance channel. These slides generally have the basket-handle form. It is not possible for fish to migrate upstream.
By-pass rivers
The by-pass river forms the link between a point upstream the dam where boats disembark and the point downstream the dam where the re-embark.