The bridges over our lake drain culverts continue to create some issues for us. Sections of the galvanized pipes used in creating the spillways have rusted in the bottom which allows water to get under the pipes and move the gravel which was filled around the pipes at installation years ago. As the gravel under the pipe erodes, the gravel which is over top of the pipe then drops down to the bottom creating potholes in our asphalt cart/walk paths. During the heavy rain last week we had another episode on #15. Our repairs since last fall which have been at least 2-3 have included concrete which is being pored into the holes which will reduce the amount of erosion around the top of the pipe. This will also keep our surface from breaking open and exposing small to moderate caverns below.
Lady as usual inspecting the work that needs to be accomplished for the day. The hole on the left is almost all the way down to the bottom of the pipe in depth. The hole on the right was a repair we made early last fall before we started to include concrete as our fill material. It was only about 1' deep.
Picture does not give the depth perception I wanted but you can see it is only about 1'foot wide but it dropped down at least 3-4'.
The repair completed and patched back over with asphalt.