A sluice is a water channel that is controlled at its head by a gate. A sluice gate is traditionally a wooden or metal plate that slides in grooves in the sides of the channel (Slurry Wall).
Sluice gates are commonly used to control water levels and flow rates in rivers and canals.
They are also used in wastewater treatment plants and to recover minerals in mining operations, and in watermills.
Water regulation occurs by changing the overall area of possible free water flow.
Sluices are mobile walls made of wood or metal reinforced with horizontal bars that is guided vertically on a purpose built frame.
A slurry wall is a technique used to build reinforced-concrete walls in areas of soft earth close to open water or with a high ground water table. This technique is typically used to build diaphragm (water-blocking) walls surrounding tunnels and open cuts, and to lay foundations. A trench is excavated to create a form for each wall. The trench is kept full of slurry at all times. The slurry prevents the trench from collapsing by providing outward pressure, which balances the inward hydraulic forces and prevents water flow into the trench. Reinforcement is then lowered in and the trench is filled with concrete, which displaces the slurry.
A gatehouse, or valve house for a dam is a structure housing sluice gates, valves, or pumps (in which case it is more accurately called a pumping station). Many gatehouses are strictly utilitarian, but especially in the nineteenth century, some were very elaborate.
Sluice gates can be maneuvered manually, with cranks, gears, mechanically, with electrical motors or by hydraulic pistons.
Numerous types of sluice gates are available, the most common of which are the flap sluice gate, vertical rising sluice gate, radial sluice gate, rising sector sluice gate, needle sluice, etc.