both sides of these stretches show some sign of water damage.

Your contractor shouild have anticipated this and prepared shoulders of an
erosion resistant type. You should call him and express your concerns politely
and firmly. A job like that is rather amateurish at best.
In our area it is common to put down shoulders of "road pack", which is crushed
limestone with all the fine stuff left in and even added to. Ir sets up almost
like concrete and makes a firm road base for driveways and highways. You may be
able to find simi;ar materials, so check with any gravel/materials supply
outfits for more info specific to your area. Good luck.

Joe