Jetties

A jetty is defined as a non-permeable structure, oriented normal to the base­line.

You can create a new groyne clicking on the ‘New jetty’ button.

You have to define the position and the bypass length of the jetty. The posi­tion of the jetty is defined by the position of the tip. The bypass length defines the section length at the tip of the jetty where longshore bypass of sediment occurs despite the presence of the structure.

Jetties as such are usually fairly long structures, and diffraction phenomena due to jetties are included in the calculation of coastline evolution.

Jetties cannot be positioned behind Offshore breakwaters.

Figure 5.16        Definition of jetty