Inverted siphon
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines a culvert as: 'A covered channel or pipe which prevents the obstruction of a watercourse or drainage path by an artificial construction.'
In relation to inverted siphons (or sag culverts), it suggests that: ‘Culverts may form part of a in inverted siphon, which is a conduit that allows water to flow beneath and obstruction and ‘uphill’ again without mechanical pumping… It is a misnomer as there is actually no siphonic action, the flow being carried under a pressure head.’
See also: Siphon.
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