[wil421]

The army corps of engineers killed Louisiana’s ability to create land by taming the mighty Mississippi River. The river used to change direction and spew sediment into the barrier islands. For the past 100 years the barrier island have been shrinking due to sediment loss.[1]

I saw a documentary recently about canals that will be used to direct sediment into the barrier islands before it reaches the Gulf.

>Until this USGS study was undertaken, environmental managers thought that the principal cause of barrier island erosion was rising sea level. Now, we know that both the longshore movement of sediment and the general absence of sand-sized sediment is the principal cause of the islands' instability. The sediments underlying coastal Louisiana are made up mostly of silts and muds which do not contribute to the building of beaches, dunes, and spits—geomorphic features associated with healthy barrier islands. In addition, long-shore currents redistribute the available sand from headland areas to embayments, depriving shorelines of much needed sand.

[1]https://pubs.usgs.gov/fs/barrier-islands/