Not from Las Canas
The sand that you are seeing in Cabarete has not been coming from Las Canas. My understanding at this time is that there is a new, legal sand mine that is not on or near a beach.
The interesting part about this whole saga is that there have always been several good (and ecologically sound) mines/quarries in the area... certain people did not want to pay the mine owners for the sand, though, and preferred to get it free from the beach.
In the end, the truck drivers (who are not paid all that much to begin with) make the same amount of money - the people who own the businesses do lose some of their profits when buying from a mine. it's a small price to pay for saving our beaches, though.
-Mark