When you put in your culvert, did they mention concreteing the sloped ends? When I put in one 4 years ago, they said I would have to concrete the sloped ends to their specs. I put in the culvert, covered with dirt, and have not yet done the concrete. I don't live there yet, but my neighbor (who I bought the property from) said they have stopped by his place a couple times asking when the ends were going to be concreted. He just told them it wasn't his anymore and he didn't know. I thought I had heard that they did not require concrete anymore, but haven't been able to confirm that. Mine would be the only one within miles any direction that had concrete.