A weir / w ɪər / 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 water level. Weirs are also used to control the flow of water for outlets of lakes, ponds, and reservoirs.

Mar 9, 2019 · A weir is a small dam built across a river to control the upstream water level. Weirs have been used for ages to control the flow of water in streams, rivers, and other water bodies. Unlike large dams which create reservoirs, the goal of building a weir across a river isn’t to create storage, but only to gain some control over the water level.

Dams, weirs, and barrages are hydraulic structures built across rivers or streams to manage water flow and meet various water management needs. Although they serve similar purposes, there are distinct differences between them based on their design, function, and impact.

Roller dams are a type of weir, or a dam that is designed to allow water to flow over the top in continuous action. They are used on rivers or other such moving bodies of water where erosion damage is undesirable, yet likely to occur.

A drop structure, also known as a grade control, sill, or weir, is a manmade structure, typically small and built on minor streams, or as part of a dam's spillway, to pass water to a lower elevation while controlling the energy and velocity of the water as it passes over.

A weir is a small barrier built across a stream or river to raise the water level slightly on the upstream side; essentially a small-scale dam. Weirs allow water to pool behind them, while allowing water to flow steadily over top of the weir. [2]

Weir, any control or barrier placed in an open channel to permit measurement of water discharge. The latter may be computed from a formula expressing the discharge in terms of crest length of the weir, depth of flow above the weir, weir geometry, and other factors.

Aug 9, 2007 · A weir is a small overflow-type dam commonly used to raise the level of a river or stream. Weirs have traditionally been used to create mill ponds in such places. Water flows over the top of a weir, although some weirs have sluice gates which release water at a …

Dams and weirs are both structures built across rivers or streams to control the flow of water. However, there are some key differences between the two. Dams are typically larger and more complex structures, designed to store water and generate hydroelectric power.

Feb 9, 2024 · A Weir is a smaller structure used to control flow, while a barrage is a larger dam-like structure built for water storage and diversion. What is the function of a weir? Weirs regulate water flow, prevent flooding, measure flow rates, aid navigation, and control sediment transport.