Managing Tidal Inlets

Jonathan Akin French (11012 Bittersweet Court, Ellicott City, MD 21042, USA)

Article ID: 850


Sandy inlets are in a dynamic equilibrium between wave-driven littoral drift acting to close them, and tidal flows keeping them open. Their beds are in a continual state of suspension and deposition, so their bathymetry and even location are always in flux. Even so, a nearly linear relationship between an inlet’s cross-sectional flow area and the inshore tidal prism is maintained - except when major wind and/or runoff events act to close or widen an inlet. Inlet location can be stabilized by jetties, but dredging may still be necessary to maintain a navigable channel. Armoring with rock large enough to resist erosion can protect an inlet bed or river mouth from excessive storm flow erosion.  Armoring can also be used as a stratagem to close inlets.


Inlet; Littoral drift; Shields parameter; Tidal prism; Cobble armoring; Coastal

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[9] French, J.A, and B.M. Harley, “Tidal Dam Closure in Singapore,” presented to the Hydraulics Group, Boston Society of Civil Engineers, 1985.



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