What is a Sluice?

A sluice is a channel, natural or human made, controlled with a gate and used to direct water to a desired location. Sluices can be used for water control, materials processing, and energy generation. Their use is quite ancient, as numerous works of art document, and discussions of using sluices can be found in ancient texts from around the world discussing engineering practices.

The sluice consists of a long channel, allowing water to flow in a given direction when the gate is released. The gate can be controlled on site or remotely and may be designed in a number of different ways to control the flow of water through the channel. Brick, concrete, wood, and metal can all be used in the construction of artificial channels, while natural channels may be enhanced with digging and artificial linings to make them more even in size and shape.

Sluices usually need to be maintained, whether they appear in nature or are created artificially. Screens may be used to keep debris out of the channel and periodically the water may need to be stopped to allow people to enter the sluice and clean it out, removing silt and other materials, as well as checking for damage to components and replacing them if necessary. Failure to perform basic maintenance on a regular basis can result in problems.

One use for a sluice is in controlling the flow of water to prevent flooding and other problems. Dams commonly utilize sluices and they can also be seen around areas prone to sudden floods of water. The sluices can be used to hold and redirect water. Another use can be seen with devices like waterwheels, where a sluice is used to direct water to the wheel to keep it turning consistently. The wheel can generate electricity or directly power something like a millstone.

In materials processing, one of the most famous uses of these devices is in gold mining, where gravel is poured into the sluice and washed with water to flush out fine particulates, including gold, allowing them to be collected. Many mining communities also employed sluices to move logs along waterways to their final destination, taking advantage of the natural flow of water instead of hauling the timber with oxen or horses. Some examples can still be seen in use in some communities and they are also stored in museums and facilities interested in maintaining historical artifacts of interest.