This is sometimes called "beach replenishment". It's popular with owners of beach front houses, but the cost-effectiveness of moving all that sand is questioned.[1]

There's an amusing case on this. If the U.S. Government widens a beach by adding sand, is the new land public property? The U.S. Supreme Court said yes, much to the annoyance of some beachfront property owners.[2] If you want to extend your own beach, buy your own sand.

[1] https://granthshala.com/jersey-shore-beach-widening-is-a-was...

[2] http://www.cnn.com/2010/CRIME/06/17/scotus.property/index.ht...