Japanese to English Tech/Engineering Environment & Ecology Levee systems

I'm looking for an appropriate way to describe this type of levee, that juts out into the main channel of a levee to slow down flow. Here's a picture of a 横堤:

http://www.1061.org/pages/levee.jpg

It comes with a caption reading:
一時的に水の流下を遅らせる機能をさらに高めるため、『横堤』が作られています。

I'm sure there's a better term than "Sideways levee".

宜しゅう。