An apparatus for creating a surfing wave in a body of water. An apparatus for the purpose of efficiently producing a variety of surfing waves having a repetition rate and size suitable for surfing. The waves are generated using a controlled up and down motion of mechanical plungers in a way that allows the control of the shape and therefore surf characteristics of the wave. A linear array of plungers is used so that they interact in different ways with bathometry of the body of water and can be changed to further alter the surfing characteristics of the waves. The motion of the individual plungers can be adjusted so that effects of different wave travel distance to the bathometry can be compensated for consistent wave characteristics.

Aquatic curtain devices and methods for forming waterway channels and reducing waterway maintenance are disclosed. Each curtain device comprises an elongated float and an elongated flexible curtain depending from a first side of the elongated float. The curtain has a bottom end with a weight extending along the entire length of the elongated float. The float is configured to be sufficiently buoyant to support the curtain in an upward direction. Each curtain device is configured for the curtain to remain in a substantially taut state when in use and accommodate fluctuations in water levels, such that the elongated weight remains on the bottom of the waterway while the elongated float remains on the surface. Artificial channels are constructed by selecting the length of the elongated float to achieve the desired channel dimensions using two or more curtain devices positioned along a desired path in a waterway.

The invention relates to a canal control system for controlling the water level or water flow in a canal system (2), comprising: (a) a centralized master controller (20), (b) a local slave controller (30), (c) a wireless communication system between the centralized master controller and the local slave controller, (d) a (fixed) reference point (8) or (movable) marker (11) relating to the water level in the canal system, and (e) an adjustable actuator (9) in the canal system, such as agate or pump, whereby the local slave controller comprises a mobile device (13) capable of displaying a human-readable instruction which an operator can act upon to set the adjustable actuator. The operator takes a picture of the water level and/or of the setting of the adjustable actuator. The data of the picture is used for updating a mathematical model of predictive control of the canal system and for calculating the setting of the present actuator and for determining which actuator is to be visited next by the operator.

An Herodotus machine, or bottom-source, up-stair, hybrid pump and step lock system, includes synchronized reciprocating cross-gate displacers with commonly synchronized gates and floating body movers; specifically including a sequence of ascending adjacent step locks separated by gates with reciprocating gears on axles aligned over respective gates. A chain over each reciprocating gear has a displacer on each end, with one displacer in the upper lock and the other displacer in the lower lock. Rotating first, the downstream displacer descends to raise the lower lock water level, while the upstream displacer rises to lower the upper lock water level, and vice versa on the reverse gear rotation. Displacers are sized such that water levels in alternate pairs of upper lock and lower lock are made the same. The gate is then opened and a watercraft can be transferred from the lower lock to the upper lock or vice versa.

An Herodotus machine, or bottom-source, up-stair, hybrid pump and step lock system, includes synchronized reciprocating cross-gate displacers with commonly synchronized gates and floating body movers; specifically including a sequence of ascending adjacent step locks separated by gates with reciprocating gears on axles aligned over respective gates. A chain over each reciprocating gear has a displacer on each end, with one displacer in the upper lock and the other displacer in the lower lock. Rotating first, the downstream displacer descends to raise the lower lock water level, while the upstream displacer rises to lower the upper lock water level, and vice versa on the reverse gear rotation. Displacers are sized such that water levels in alternate pairs of upper lock and lower lock are made the same. The gate is then opened and a watercraft can be transferred from the lower lock to the upper lock or vice versa.

This device serves to improve water quality under gravity flow conditions. The water quality treatment device traps floating debris with replaceable netting, it contains oil spills and settles sediment in self-cleaning settling cells above a collection bunker inside a chamber. The device directs the water below the inclined cells, through the inclined cells, or over the inclined cells, depending on the inflow intensity. All inflowing water enters the net cavity and the net is supported by the inclined cell assembly. The pollutant collection surfaces are overlapping each other and aligned with the water flow direction. A hinged baffle with orifices controls the flow rate through the inclined cells. The netting is replaceable when filled with debris through an access opening in the ceiling of the chamber. The sediment bunker is cleaned through access openings in the ceiling from the chamber inflow side and the exit side.

Coverings for structures which can be installed in the ground are known. In order to lock the covering on the structure, closures are known which comprise a snap bolt which is designed in such a way and is mounted movably on the covering (20) against the force of a spring device in such a way that, during closing of the covering (20), the snap bolt is forced back and snaps in behind a counterbearing (14, 14) fixed to the structure in a closure position. To simplify the arrangement and also to improve durability, it is proposed that the snap bolt is mounted in a housing (40) which can be fastened in a housing receptacle of the covering (20).

A bulkhead system and a method of implementing such a bulkhead system in relation to a dam are disclosed herein. In one example embodiment, such a method includes providing a plurality of bulkhead sections assembled together as a bulkhead assembly, and coupling first side, second side, and bottom assemblies respectively to a first end, second end, and bottom surface respectively of the bulkhead assembly. Further, the method includes causing a first of the bulkhead sections to receive a respective amount of ballast within an internal cavity therewithin, receiving water pressure at an upstream surface of the bulkhead assembly such that the bulkhead system is forced against the dam and substantially sealed in relation thereto, and operating to counteract the water pressure and thereby prevent or limit the flow of water past the dam, where the operating is performed at least in part by the side assemblies and bottom assembly.

An apparatus for holding back, and diverting, fish in bodies of water by the arrangement of parallel cables (S) braced between two or more abutments (W), wherein the distance between the cables is small enough to prevent fish from swimming through the apparatus.

An apparatus for holding back, and diverting, fish in bodies of water by the arrangement of parallel cables (S) braced between two or more abutments (W), wherein the distance between the cables is small enough to prevent fish from swimming through the apparatus.