I've heard they've done it in the past by not dredging the sandbar obviously and not making it flat when the refill it as well as using the right type of sand.
they never park the barge right on the bar & pull sand from there onto the beach. the barge is frequently located miles offshore, pulling sand off the bottom & then sending it through a pipeline to the beach. the ACoE doesn't take the time to a proper analysis of the type of sand it's parking the dredge over to do these projects. sand is sand, they think. the local, surfable bars are destroyed by the flattening of the beaches as they are expanded eastward. even assuring a proper grain match won't prevent that from happening in the short term. so again i'll ask-how do you propose replenishing the beaches w/out dredging?