Sand Backpass & Bypass
Sand Backpass involves catching sand as it is washed off a beach and returning it to the beach where it came from.
Sand is most often captured at inlets and passes such as Longboat Pass and New Pass.
Sand ByPass is the same process except here the sand is bypassed around an inlet or pass and posited on the next beach along the natural littoral sand movement.
In both cases the sand is not allowed to accumulate in the channels. The sand is either returned to the beach of origin or another beach. In the case of Hillsboro Inlet in Broward County, Florida sand is bypassed southward using a jetty to trap the sand at the inlet and a small shallow draft dredge to transport the trapped sand to the next beach which would otherwise be adversely affected by the Hillsboro Inlet jetty.
Miami-Dade County in 2008 legislated funds for the construction of sand back pass projects. The Hillsboro Inlet sand bypass program has been functioning for decades.
Sand Back Pass and Bypass projects are designed to resolve two beach erosion issues - sand loss from beaches near inlets and passes and silting-in of the channels with that sand. Sand bypassing and back passing are continuous ongoing projects. The cost per cubic yard of reclaimed sand at Hillsboro Inlet is less than one dollar. Compare this to the ten plus dollars per yard for the most recent nourishment on Longboat Key and the looming twenty to forty-five dollars a yard for our next scheduled maintenance.
Another aspect of continious beach management is that the beaches are always in peak condition whereas periodic nourishment begins a process of beach loss that is more rapid during the years just after nourishment. The rate of sand loss diminishes over time as the shoreline tries to reach equilibrium.