Editing Jetty (section)

==At lagoon outlets==
[[File:Private jetties near the mouth of the Nambucca River, NSW.jpg|thumb|Private jetties near the mouth of the [[Nambucca River]], New South Wales, Australia|alt=]]

A small tidal rise spreading tidal water over a large expanse of [[lagoon]] or inland backwater causes the influx and efflux of the tide to maintain a deep channel through a narrows no longer confined by a bank on each side, becomes dispersed, and owing to the reduction of its scouring force, is no longer able at a moderate distance from the shore effectually to resist the action of tending to form a continuous beach in front of the outlet. Hence a [[Shoal|bar]] is produced that diminishes the available depth in the approach channel. By carrying out a solid jetty over the bar, however on each side of the outlet, the tidal currents are concentrated in the channel across the bar, and lower it by scour. Thus the available depth of the approach channels to [[Venice]] through the [[Malamocco]] and [[Lido di Venezia|Lido]] outlets from the [[Venetian Lagoon]] have been deepened several feet (metres) over their bars by jetties of rubble, carried out across the [[Intertidal zone|foreshore]] into deep water on both sides of the channel.

Other examples are provided by the long jetties extended into the sea in front of the entrance to [[Charleston, South Carolina|Charleston]] harbour, formerly constructed of [[fascine]]s weighed down with stone and logs, but subsequently of rubble stone, and by the two converging rubble jetties carried out from each shore of [[Dublin Bay]] for deepening the approach to [[Dublin]] harbour.<ref name="EB1911" />

Jetties have the adverse effect of endangering Surf Culture as a whole with their ability to destroy surf breaks.<ref>{{Cite web |last=Journal |first=Men's |date=2019-12-05 |title=Surfing’s endangered and extinct waves |url=https://www.mensjournal.com/travel/endangered-waves |access-date=2024-12-16 |website=Men's Journal |language=en}}</ref>