Definitions for "Jetties"
Manmade structures consisting of stone, earth, or timber embankments projecting into the water on one or both sides of a channel. Their primary purpose is to prevent the accumulation of current-borne silt in channels, but they may also act to some degree as a breakwater. Jetties are often built on both sides of the entrance channel to the mouth of a river or to a tidal harbor to concentrate and restrict the direction of the current, thus tending to increase the depth of water over the bar.