Water-intake structures divert water from a river or channel for the purposes of water supply, hydroelectric power and irrigation. Engineers consider many factors when designing water intake structures. Historically, water diversion has focused on large-scale structures. In recent years, environmental concerns have resulted in smaller and medium-size structures, such as weirs and sluice gates.
Lateral Intake Structure with Damming
Lateral intake structures are typically designed using weirs. The most common design uses a diversion structure, along with a weir. The weir, usually oriented perpendicularly across the river, provides a way to partially dam the water in a river. The damming effect allows the water to be held at a constant level, so an intake structure can effectively divert water. Intake structures are usually one or more sluice gates and open channels.
Lateral Intake Structure Without Damming
The application of lateral intake structures without damming is suitable for rivers with a small amount of flow, up to two cubic meters per second. To determine if a lateral intake structure is necessary without damming the water, detailed precipitation, streamflow and geomorphology data may need to be analysed.
Bottom Intake Structure
Also called Tyrolean intake, bottom intake structures are used on straight reaches of river, where the water contains very little suspended particulate matter. To design a bottom intake structure, it is first necessary to construct a collection canal beneath the river bottom, and cover it with a screen.
Overhead Intake Structure
Commonly used for energy production on large rivers, overhead intake structures consist of inlets arranged in a series of piers. Larger flows require larger intake structures, so it becomes critical to design adequate energy dissipation structures downstream of the diversion, so the stream channel does not erode.