The inverted siphon

An inverted siphon is a conduit carrying a liquid between two reservoirs with different water levels, in which the pipe pressure would be larger - to much larger - than atmospheric. In the inverted siphon, the liquid flows from the upper to lower reservoir. The inverted siphon may be used to carry water supply, sewage or stormwater under streams, roadways, or some depression in the ground. Shallow inverted siphons are sometimes called culverts. The flow in an inverted siphon is driven by gravity.
The inverted siphon design was used in Antiquity, for example along the Roman aqueducts at Aspendos (Turkey) and Gier (France).
The inverted siphon is sometimes called improperly a siphon. The expression is incorrect, because a siphon is a pipe connecting two reservoirs of different water levels, in which the liquid pressure in the pipe would locally become less than atmospheric.
The operation of inverted siphons and siphons constitute a basic application of fluid mechanics to open channel hydraulics, hydraulic structures, and aqueducts. This is further discussed in a number of relevant RUclips video movies in the same channel at: { / @hubert_chanson }.
 
Hydraulic Engineering and Applied Hydrodynamics in Hubert Chanson RUclips channel { / @hubert_chanson }
Fundamentals of open channel hydraulics [Playlist]
Advanced hydraulics of open channel flow [Playlist]
Hydraulic structures [Playlist]
The Equation of Conservation of Mass in Fluid Mechanics { • The Equation of Conser... }
Equation of conservation of energy in fluid mechanics { • Equation of conservati... }
The siphon { • The siphon }
The air-regulated siphon spillway
Acknowledgements
Late Dr Jean BURDY
Ms Ya-Hui CHOU
References
BURDY, J. (1979). "Lyon. Lugdunum et ses Quatre Aqueducs." Dossiers de l'Archéologie, Séries Les Aqueducs Romains, Vol. 38, Oct.-Nov., pp. 62-73.
BURDY, J. (2002). "Les Aqueducs Romains de Lyon." Presses Universitaires de Lyon, Lyon, France, 204 pages.
STREETER, V.L., and WYLIE, E.B. (1981). "Fluid Mechanics." McGraw-Hill, 1st SI Metric edition, Singapore.
ORTLOFF, C.R., and KASSINOS, A. (2003). "Computational Fluid Dynamics Investigation of the Hydraulics Behaviour of the Roman Inverted Siphon System at Aspendos, Turkey." Jl of Archaeological Science, Vol. 30, pp. 417-428.
CHANSON, H. (2004). "The Hydraulics of Open Channel Flow: An Introduction." Butterworth-Heinemann, 2nd edition, Oxford, UK, 630 pages (ISBN 978 0 7506 5978 9).
NOVAK, P., MOFFAT, A.I.B., NALLURI, C., and NARAYANAN, R. (2007). "Hydraulic Structures." Taylor & Francis, London, UK, 4th edition, 700 pages.