The lake to the right of the fifth green is gone, and in its place is a growing natural sandy area. You can see it to the left of the above picture, which was taken from behind the fifth green looking back toward the tee box.
Here is the before picture:
The dune will serve as a waste area and an obstacle for approach shots, and it will also separate the fifth green from the seventh tee box and fairway.
Below is an example of the kind of natural sandy areas players will encounter throughout the course: