A manually operated needle dam-type weir near Revin on the Meuse, FranceNeedle dam in the Reuss in Lucerne, SwitzerlandNeedle dam near Louisa, KY in the United States
A needle dam is a weir designed to maintain the level or flow of a river through the use of thin "needles" of wood. The needles are leaned against a solid frame and are not intended to be water-tight. Individual needles can be added or removed by hand to constrict the flow of the river, forming a sluice.
Whitewater forms in the context of rapids, in particular, when a river's gradient changes enough to generate so much turbulence that air is trapped within the water. This forms an unstable current that froths, making the water appear opaque and white.
Lake Lucerne is a lake in central Switzerland and the fourth largest in the country.
A weir or low-head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level. Weirs are also used to control the flow of water for outlets of lakes, ponds, and reservoirs. There are many weir designs, but commonly water flows freely over the top of the weir crest before cascading down to a lower level. There is no single definition as to what constitutes a weir.
A sluice is a water channel containing a sluice gate, a type of lock to manage the water flow and water level. It can also be an open channel which processes material, such as a river sluice used in gold prospecting or fossicking. A mill race, leet, flume, penstock or lade is a sluice channeling water toward a water mill. The terms sluice, sluice gate, knife gate, and slide gate are used interchangeably in the water and wastewater control industry.
The Reuss is a river in Switzerland. With a length of 164 kilometres (102 mi) and a drainage basin of 3,426 square kilometres (1,323 sq mi), it is the fourth largest river in Switzerland. The upper Reuss forms the main valley of the canton of Uri. The course of the lower Reuss runs from Lake Lucerne to the confluence with the Aare at Brugg and Windisch.
The Shetucket River is a tributary of the Thames River, 20.4 miles (32.8 km) long, in eastern Connecticut in the United States.
The English River Thames is navigable from Cricklade or Lechlade to the sea, and this part of the river falls 71 meters (234 feet). There are 45 locks on the river, each with one or more adjacent weirs. These lock and weir combinations are used for controlling the flow of water down the river, most notably when there is a risk of flooding, and provide for navigation above the tideway.
A canal pound, reach, or level, is the stretch of level water impounded between two canal locks. Canal pounds can vary in length from the non-existent, where two or more immediately adjacent locks form a lock staircase, to many kilometres/miles.
Floodgates, also called stop gates, are adjustable gates used to control water flow in flood barriers, reservoir, river, stream, or levee systems. They may be designed to set spillway crest heights in dams, to adjust flow rates in sluices and canals, or they may be designed to stop water flow entirely as part of a levee or storm surge system. Since most of these devices operate by controlling the water surface elevation being stored or routed, they are also known as crest gates. In the case of flood bypass systems, floodgates sometimes are also used to lower the water levels in a main river or canal channels by allowing more water to flow into a flood bypass or detention basin when the main river or canal is approaching a flood stage.
The Cotter River, a perennial river of the Murrumbidgee catchment within the Murray–Darling basin, is located in the Australian Capital Territory, Australia. The Cotter River, together with the Queanbeyan River, is one of two rivers that provides potable water to the Canberra and Queanbeyan region.
The Tuckasegee River flows entirely within western North Carolina. It begins its course in Jackson County below Cullowhee at the confluence of Panthertown and Greenland creeks.
A flash lock is a type of lock for river or canal transport.
The Ross River is a river in North Queensland, Australia. The 49-kilometre (30 mi) long river flows through the city of Townsville and empties into the Coral Sea. It is the major waterway flowing through Townsville and the city's main source of drinking water.
The Engelberger Aa is a river in Switzerland. It rises west of the Surenenpass in the Canton of Uri, flows through the valley of Engelberg (Obwalden) and Nidwalden. At Buochs it flows into Lake Lucerne and is therefore a tributary of the Reuss, which drains the lake.
Hertford Castle Weir is a weir located in Hertford near to Hertford Castle and next to Hertford Theatre.
The Ware River is a 35.4-mile-long (57.0 km) river in central Massachusetts. It has two forks, its West Branch, which begins in Hubbardston, Massachusetts, and its East Branch, which begins in Westminster, Massachusetts. The Ware River flows southwest through the middle of the state, joins the Quaboag River at Three Rivers, Massachusetts, to form the Chicopee River on its way to the Connecticut River.
The Staines Reservoirs are two large pumped storage reservoirs sitting to the east of the King George VI Reservoir near Heathrow airport in Surrey within the Colne Valley regional park. The village of Stanwell is mainly to the north east, and the town of Staines is to the south.
Sunbury Lock is a lock complex of the River Thames in England near Walton-on-Thames in north-west Surrey, the third lowest of forty four on the non-tidal reaches. The complex adjoins the right, southern bank about 1⁄2 mile (0.80 km) downstream of the Weir Hotel.
Northmoor Lock is a lock on the River Thames in Oxfordshire, England, on the northern bank about a mile from Northmoor.
Three Mills Wall River Weir is a weir on the Bow Back Rivers, in Mill Meads in the London Borough of Newham, England, near to Three Mills. It was built in 2009, when the Bow Back Rivers were refurbished to make them a key feature of the Queen Elizabeth Olympic Park, and maintains water levels through much of the park in conjunction with the Three Mills Lock and sluice on the Prescott Channel.
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