The gravel wash-in will likely be the biggest problem for you. I live near Ithaca, NY which has a lot of parks with dammed creeks for swimming holes. Beautiful places! Each spring they have to re-excavate out the holes for swimming, removing a LOT of material. Some years the parks remain closed as the swim holes will be overflowing with gravel and completely plugged.

Two of the better-known parks there:
http://parks.ny.gov/parks/151/details.aspx
http://parks.ny.gov/parks/135/details.aspx