Tokyo floodgates to protect from typhoon surges.

Floodgates are adjustable gates to control water flow in stream, reservoir or levee systems. They may be designed to adjust flow rates in sluices and canals, or to set spillway crest heights in dams. Or they may be designed to stop water flow entirely as part of a levee or storm surge system. Image File history File links Download high resolution version (1024x768, 326 KB) Floodgates, Tokyo. ... Image File history File links Download high resolution version (1024x768, 326 KB) Floodgates, Tokyo. ... Image:Tokyo nightview. ... This article is about weather phenomena. ... Running Stream The primary meaning of stream is a body of water, confined within a bed and banks and having a detectable current. ... A lake is a body of water surrounded by land. ... A levee, levée (from the feminine past participle of the French verb lever, to raise), floodbank or stopbank is a natural or artificial embankment or dike, usually earthen, which parallels the course of a river. ... A sluice is a water channel that is controlled at its head by a gate. ... Categories: Water-transport stubs | Canals | Water transport ... Spillway of Llyn Brianne dam in Wales A Spillway is a structure used to provide for the controlled release of flood flows from a dam or levee into a downstream area, typically being the river that has been dammed. ... Scrivener Dam, Canberra Australia, was engineered to withstand a once-in-5000-years flood event A dam is a barrier across flowing water that obstructs, directs or retards the flow, often creating a reservoir, lake or impoundment. ... Graphic illustrating storm surge. ...

Types of floodgates

A sluice gate on the Harran canal.

A floodwall gate at Harlan, Kentucky.

• Bulkhead gates are vertical walls with movable, or re-movable, sections. Movable sections can be lifted to allow water to pass underneath (as in a sluice gate). Designs with removable sections allow water to pass over top and historically used stacked timbers to set the dam's crest height. Some floodgates in large levee systems slide sideways to open for various traffic. Miter gates are used in ship locks and usually close at an 18° angle to form an approximate arch.

Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... The Southeastern Anatolia Project (Turkish: Güneydoğu Anadolu Projesi) or GAP is the dam/irrigation project consisting of a series of 21 dams on the Tigris and Euphrates rivers primarily to be constructed in the south eastern region of Turkey. ... Image File history File links Floodgate, floodwall source:http://www. ... Image File history File links Floodgate, floodwall source:http://www. ... A sluice is a water channel that is controlled at its head by a gate. ... Canal locks in England. ...

A hinged crest gate during installation.

Fish belly flap gates at the Scrivener Dam, Canberra.

• Hinged crest gates, are wall sections that rotate from vertical to horizontal, thereby varying the height of the dam. They are generally controlled with hydraulic power.

Variations;

• flap gate
• fish-belly flap gates
• Bascule® gates
• Pelican® gates

Image File history File links Floodgate, spillway crest, bascule, installation source:http://www. ... Image File history File links Floodgate, spillway crest, bascule, installation source:http://www. ... Download high resolution version (1024x768, 150 KB)formerly Image:Srivener Dam Canberra-01JAC.jpg Scrivener Dam, Canberra 2004 - Photo taken by John Conway and released under the GFDL File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Download high resolution version (1024x768, 150 KB)formerly Image:Srivener Dam Canberra-01JAC.jpg Scrivener Dam, Canberra 2004 - Photo taken by John Conway and released under the GFDL File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Hydraulically powered cylinders are visible on this excavator. ...

Tainter gate diagram.

Tainter gates and spillway.

• Radial gates are rotary gates consisting of cylindrical sections. They may rotate vertically or horizontally. Tainter gates are a vertical design that rotates up to allow water to pass underneath. Low friction trunnion bearings, along with a face shape that balances hydrostatic forces, allow this design close under its own weight as a safety feature.

Image File history File links LgRadialGatefigc4-6. ... Image File history File links LgRadialGatefigc4-6. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Image File history File links Download high resolution version (2400x1800, 703 KB) Tainter gates (floodgates), Timothy lake dam, Mount Hood National Forest. ... Image File history File links Download high resolution version (2400x1800, 703 KB) Tainter gates (floodgates), Timothy lake dam, Mount Hood National Forest. ... This article needs to be cleaned up to conform to a higher standard of quality. ... (Steam Engine) A gudgeon on each side of an oscillating steam cylinder, to support it. ... A bearing is a component used to reduce friction in a machine. ... Fluid pressure is the pressure on an object submerged in a fluid. ...

Drum gates are are controled with valves.

Drum gates on a diversion dam.

• Drum gates are hollow gate sections that float on water. They are pinned to rotate up or down. Allowing water into or out of their flotation chamber adjusts the dam's crest height.

Image File history File links Download high resolution version (747x626, 84 KB) Floodgate, drum Source:me, SVG available on request File links The following pages link to this file: Floodgate ... Image File history File links Download high resolution version (747x626, 84 KB) Floodgate, drum Source:me, SVG available on request File links The following pages link to this file: Floodgate ... A diversion dam is a type of dam that diverts all or a portion of the flow of a river from its natural course. ...

A roller gate on the Mississippi.

Clamshell floodgates

• Roller gates are large cylinders that move in an angled slot. They are hoisted with a chain and have a cogged design that interfaces with their slot.
• Clamshell gates have an external clamshell leaf design.

Image File history File links Floodgate, roller. ... Image File history File links Floodgate, roller. ... State nickname: Magnolia State Other U.S. States Capital Jackson Largest city Jackson Governor Haley Barbour (R) Official languages English Area 125,546 km² (32nd)  - Land 121,606 km²  - Water 3,940 km² (3%) Population (2000)  - Population 2,697,243 (31st)  - Density 23. ... Image File history File links Download high resolution version (1615x1345, 383 KB) Floodgate, clamshell, Arrowrock dam source: http://www. ... Image File history File links Download high resolution version (1615x1345, 383 KB) Floodgate, clamshell, Arrowrock dam source: http://www. ...

Floodgate valves

Discharge from a Howell-Bunger valve.

Valves used in floodgate applications have a variety of design requirements and are usually located at the base of dams. Often, the most important requirement (besides requlating flow) is energy dissapaion. Since water is very heavy, it exits the base of a dam with the enormous force of water pushing from above. Unless this energy is dissipated, the flow can erode nearby rock and soil and damage nearby structures. Image File history File links Download high resolution version (1200x900, 203 KB) Discharge from a Howell-Bunger valve, below Timothy lake dam, Mount Hood National Forest. ... Image File history File links Download high resolution version (1200x900, 203 KB) Discharge from a Howell-Bunger valve, below Timothy lake dam, Mount Hood National Forest. ...

Other design requirements are: operating pressure head, flow rate, wether the valve operates above or below water, regulating precision and cost. In fluid dynamics, head refers to the constant right hand side in the incompressible steady version of Bernoullis equation. ...

• Fixed cone valves, also known as Howell-Bunger valves, are designed to dissipate the energy from a water flow during reservoir discharge. They are a round pipe section with an adjustable sleeve gate and cone at the discharge end. Flow is varied by moving the sleeve away or towards its cone seat. The design allows high pressure water from the base of a dam to be released without causing erosion to the surrounding environment. Fixed cone valves are able to handle heads up to 1,000 feet.

• Hollow jet valves are a type of needle valve used for floodgate discharge. A cone and seat are inside a pipe. Water flows through an annular gap between the pipe and cone when it is moved downstream, away from the seat. Ribs support the bulb assembly and supply air for water jet stabilization.

• Ring jet valves are similar to fixed cone valves, but have an integral collar that discharges water in a narrow stream. They are suitable for heads up to 175 feet.

• Jet flow gate, similar to a gate valve but with a conical restriction prior to the gate leaf that focuses the water into a jet. They were developed in the 1940's by the United States Bureau of Reclamation to allow fine control of discharge flow without the cavitation seen in regular gate valves. Jet flow gates are able to handle heads up to 500 feet.

Scrivener Dam, Canberra Australia, was engineered to withstand a once-in-5000-years flood event A dam is a barrier across flowing water that obstructs, directs or retards the flow, often creating a reservoir, lake or impoundment. ... Look up Erosion on Wiktionary, the free dictionary Severe soil erosion in a wheat field near Washington State University, USA. Erosion is the displacement of solids (soil, mud, rock, and so forth) by the agents of wind, water, ice, movement in response to gravity, or living organisms (in the case... In fluid dynamics, head refers to the constant right hand side in the incompressible steady version of Bernoullis equation. ... A gate valve is a valve that opens by lifting a round or rectangular gate out of the path of the fluid. ... The United States Bureau of Reclamation (Formerly the United States Reclamation Service) is a division of the U.S. Department of the Interior which oversees water development projects in the western United States. ... Cavitation is the phenomenon where small cavities of partial vacuum form in fluid, then rapidly collapse, producing a sharp sound. ...

References

1. US Army Corps of Engineers, "Planning and Design of Navigation Dams", Engineering manual 1110-2-2607, 31 July 1995, Chapter 5, Overview of gate types (.1M pdf)

See also

• Canal lock

Canal locks in England. ...

External links

• A workshop for small floodgates by the State of New South Wales, 5.4 M pdf