Sharp-crested weirs are control structures causing a defined backwater. Additionally, they are often used to determine the discharge of an open channel.
HM 160.30 contains four different plate weirs as sharp-crested weirs. The fundamentals of flow over sharp-crested weirs are demonstrated with the rectangular weir with optional aeration. The other weirs are typical measuring weirs with defined openings: the opening of the Thomson weir is triangular, the opening of the Rehbock weir is rectangular and for the Cipoletti weir, it’s trapezoidal.