Just be very careful not to use anything that could become a "missile" that the mower could project out and hurt someone.
My folks have a huge area on both sides of their culvert that is "rip-rap'd" with stone. This serves to both reduce erosion and to ensure no mowers can get near the actual culvert. But then, the county performs mowing operations along their roadway, and they only go out from the edge of the gravel about 1 mower width. They perform these operations regularly - at least once every 5 years (or less).