Hydrostadium, créateurs en eau vive, stade d'eau vive, espace d'eau vive, parcours d'eau vive, canoë, kayak, hydrospeed, rafting, tubbing, hot dog, barge d'eau vive, vague à surf, passe à poissons et canoës, filiale EDF, obstacles mobiles omniflots...

Hydrostadium and its ingénieurs worked on all the projects that are presented hereafter.

Specific fish passes

The pass consisting of successive basins

The successive basin pass is a very old principle which means that we have a lot of feed-back.

The principle of this pass is the division of the difference in height by the installation of successive basins in a row. The dimensioning of each basin depends on the requested energy dissipation related to the specimen of the migrating fish. One of the advantages of this type of fish pass is the high flexibility regarding the upstream and downstream water level.
Lifts for fish

Migrating fish can get over high dams thanks to these lifts for fish. One of the main difficulties in the concept of the fish lifts is the fact that the fish must be « captured » in a cage.

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Specific 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.

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Combined passes

Destruction of a dam

The destruction of a dam although a very simple solution is very difficult to do. Most of the time built several centuries ago, each dam is the basis of an ecological balance between several elements such as the stability of the upstream river banks and the level of the water table.... The decision to destruct a dam can only be based on important hydraulic and environmental studies. This definitive solution is the most satified one only from an intellectual point of view.
The creation of an opening

The creation of an opening which is an intermediate solution results in the allmost entire preservation of the ecological and hydraulical balance created by the dam. Once more, the greatest difficulty consists in the dimensioning and positioning of the opening in order to ensure over a large period the passage of canoes and kayaks and preserve the balance of nature at the same time. Attention must be paid in particular to the fact that the opening won't create dangerous currents at a certain flow. Most of the time the openings are situated away from the river banks to avoid any phenomenon of erosion due to the water speed and the countercurrents. The fact that these openings are situated away from the river banks emphasizes the difficulty to locate them from a boat.
Slides with wooden or polythene speed-reducers

The most important advantage of this type of slides is the possibility for certain fishes to migrate up- AND downstream.
Successive passes before a dam

This solution is perhaps the right compromise between the destruction and the maintain of the dam. The dividing up of the waterfall into several smaller successive falls downstream the principal dam makes that this pass can be easily integrated into the landscape of the existing construction. Following the form of the dams, the indentation and their dimensioning, this type of pass helps not only fish to migrate but also makes it possible for canoes and kayaks to get over the dam.