The device, comes to solve the problem of the Spanish rivers by the absence of migratory fish in dams, salmon, sea trout, shadles, sabogas, lampreys, eels, etc. The ascent of the fish is achieved by the mechanical actuation of an endless screw or Archimedes, located in an adapted channel, which, turning on its axis clockwise, allows water to be raised from the rivers including the existing fish in the bank. The descent of the fish is achieved by the passage of water with the fish through the screw. The passage induces an anti-clockwise rotation in the screw that is used to generate electricity. The sale of electricity allows investments to be financed for the environmental effect essential for compliance with current legislation and the provisions of the 2015-2021 Hydrological Plans, at no cost to the concessionaire of the exploitation nor the Spanish state.

The device for the migration of aquatic animals has a channel body with an upstream end and a downstream end as well as a longitudinal axis. The bottom of the channel body is provided with a cover layer made of natural bottom substrate and/or debris material and has a ridge running along the longitudinal axis. Plate-shaped lamellae are arranged in the channel body transversely to the longitudinal axis of the channel body. The lamellae have a downwardly open lower cut-out, which is limited at the top by a transverse element, wherein the cross-sectional area of the lower cut-out is dimensioned in such a way that the ridge of the cover layer may be accommodated in the lower cut-out. The upper edge of the transverse element has a preferably curved contour, which is inclined towards the centre of the channel and defines a lower boundary of an upper cut-out of the lamellae extending upwards from the transverse element.

A precast dam structure includes at least two precast segments coupled together via linkages and a flow path structure. The flow path structure defines a flow path having an intake port and a draft port and is associated with at least one of the at least two precast segments. The flow path structure is configured to provide a change in flow direction, either internally or externally, from the at least one of the at least two precast segments.

A fish pass system includes a helical blade having an outside diameter and an inside diameter extending between a first side of the helical blade and a second side of the helical blade. The inside diameter controls a flow of water flowing in a direction from the first side to the second side, and the inside diameter defines an open center of the fish pass system. Fish traveling in an opposite direction to the direction of the flow of the water pass through the fish pass system by riding in a space between helical blades as the helical blades are rotating, and fish traveling in the direction of the flow of the water pass through the open center of the fish pass system by swimming or moving over the inside diameter of the helical blades.

An apparatus for guiding fish through a body of water having a water flow includes one or more hydrofoil element oriented in the body of water to produce an asymmetric flow field that has a fast, low turbulent flow on one side of the element and a slow, high turbulent flow on the other side of the element. Positively rheotactic fish have a preference for one side versus the other and so are guided in a desired direction. Systems and method that utilize the apparatus can be used to guide fish away from infrastructure such as dams, locks, levees, flood weirs, and other diversion points.

The present disclosure discloses a water-replenishing fishway with an adaptively-adjusted floating dock, comprising: a fishway body, wherein the bottom of the fishway body is rotationally connected with a floating dock structure, an auxiliary swimming structure is arranged inside the fishway body, and an adjusting structure used to adjust the auxiliary swimming board of the auxiliary swimming structure is arranged on said floating dock structure. The present disclosure can adaptively adjust the angle of the fishway body and auxiliary swimming board and effectively assist the fish's migration.

Migrating fish often want to travel between different bodies of water, which may be positioned at different heights. To overcome these heights, water passages may be used that provide a water path at a slope over which a fish is able to swim up. A compact housing is provided by allowing a water guide over which the water flow flows to rotate around an axis parallel to gravity in a helical shape. The fish lock may be provided with a resting chamber which comprises a volume of water with a low flow velocity. Sensors and a controller may be provided to control a flow rate of the water through the fish lock according to for example the type of fish passing through the fish lock and an administrator may monitor the fish lock at a distance and may be contacted in case of malfunction.

A method is provided for the artificial erosion of dammed bodies of water, wherein an average grain size distribution of sediments in the dammed body of water is determined across the ground surface of the dammed body of water. A sediment requirement for downstream water is determined, and as a result, at least one displacement of the sediments in the dammed body of water into the downstream water takes place in accordance with the sediment requirements for the downstream water. Advantageously, requirements regarding at least the quantity and grain size of the sediment for the downstream water are determined.

A precast dam structure includes at least two precast segments coupled together via linkages and a flow path structure. The flow path structure defines a flow path having an intake port and a draft port and is associated with at least one of the at least two precast segments. The flow path structure is configured to provide a change in flow direction, either internally or externally, from the at least one of the at least two precast segments.

Disclosed is a floating river module that has at least one buoy to float also the other parts of the module, the other parts including an at least partly sub-merged vertical wall element being solidly attached to the buoy, the vertical wall element including a horizontal keel element. Also disclosed is a floating river system formed from such modules for guidance of fish.