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.

Fluid flow enhancing devices disclosed herein are adapted to enhance flow of fluid through subsurface watershed conduits, for example, culverts, drainpipe and the like. Such fluid flow enhancing devices advantageously enhance watershed runoff functionality in subsurface watershed conduits by altering watershed flow from a parabolic flow pattern to a rotational flow pattern while still accommodating fish passage requirements. This change in flow pattern beneficially provides turbulence that disrupts and flushes debris out of the subsurface watershed conduits. This disruption and flushing establishes a passive cleaning functionality within the subsurface watershed conduits that serves to clean the subsurface watershed conduits after suitable upstream water delivery event (e.g., heavy rain, controlled water release, etc.). In doing so, these fluid flow enhancing devices overcome one or more shortcomings associated with subsurface watershed conduits in a manner that overcomes drawbacks associated with conventional design and in-use considerations for such subsurface watershed conduits.

A fish ladder includes a channel with first and second sidewalls spaced apart at a channel width distance. Each of a first plurality of side-baffles is attached to the first sidewall and each of a second plurality of side-baffles is attached to the second sidewall. Each side-baffle extends a predetermined distance into the channel. A first slot opening width distance from a tip of each one of the first plurality of side-baffles across the channel and perpendicular to the second sidewall substantially equals a second slot opening width distance from a tip of each one of the second plurality of side-baffles across the channel and perpendicular to the first sidewall. A side-baffle spacing distance from a tip of each one of the first plurality of side-baffles and perpendicular to a corresponding one of the second plurality of side-baffles located upstream substantially equals the first and second slot opening width distances.

A runner for a hydraulic turbine configured to reduce fish mortality. The runner includes a hub and a plurality of blades extending from the hub. Each blade includes a root connected to the hub and a tip opposite the root. Each blade further includes a leading edge opposite a trailing edge, and a ratio of a thickness of the leading edge to a diameter of the runner can range from about 0.06 to about 0.35. Further, each blade has a leading edge that is curved relative to a radial axis of the runner.

The present disclosure relates to a floatable island and to the use of a floatable island, the floatable island comprising at least one layer, and the layer has a structure containing grains, the grains consisting of an expanded mineral material.

Disclosed is a system and method for transferring fish past a barrier between an upper and lower body of water, including an inlet conduit 11 connecting the upper body to a transfer chamber 13 adjacent the lower body, a delivery conduit 15 connecting the transfer chamber 13 to a level above the surface of the upper body, a valve 12 between the inlet conduit and the transfer chamber, and a gate 14 between the transfer chamber 13 and the lower body. The inlet conduit 11 holds sufficient water so that, once the gate 14 is closed and the valve 12 is opened, fish in the transfer chamber 13 are transported with the water in the transfer chamber through the delivery conduit 15 to an outlet 16.

Aspects of the present disclosure involve hydraulic systems and methods for altering a flow of a body of water, such as a river, channel, and/or other flowing or uncontained bodies of water. In one aspect, a hydraulic system provides a velocity barrier for the impedance of aquatic organism migration. More particularly, the velocity barrier may be adapted based on the swimming capabilities of one or more aquatic organisms to impede migration. The aquatic organism may be one or more species of fish, such as species sea lamprey (Petromyzon marinus). The example implementations shown and described herein reference the restriction of the sea lamprey. However, it will be appreciated that other aquatic organisms could be restricted by the presently disclosed technology, for example, with different hydraulic targets depending on swimming capabilities.

Fluid flow enhancing devices disclosed herein are adapted to enhance flow of fluid through subsurface watershed conduits, for example, culverts, drainpipe and the like. Such fluid flow enhancing devices advantageously enhance watershed runoff functionality in subsurface watershed conduits by altering watershed flow from a parabolic flow pattern to a rotational flow pattern while still accommodating fish passage requirements. This change in flow pattern beneficially provides turbulence that disrupts and flushes debris out of the subsurface watershed conduits. This disruption and flushing establishes a passive cleaning functionality within the subsurface watershed conduits that serves to clean the subsurface watershed conduits after suitable upstream water delivery event (e.g., heavy rain, controlled water release, etc.). In doing so, these fluid flow enhancing devices overcome one or more shortcomings associated with subsurface watershed conduits in a manner that overcomes drawbacks associated with conventional design and in-use considerations for such subsurface watershed conduits.

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.

A runner for a hydraulic turbine configured to reduce fish mortality. The runner includes a hub and a plurality of blades extending from the hub. Each blade includes a root connected to the hub and a tip opposite the root. Each blade further includes a leading edge opposite a trailing edge, and a ratio of a thickness of the leading edge to a diameter of the runner can range from about 0.06 to about 0.35. Further, each blade has a leading edge that is curved relative to a radial axis of the runner.