Dry leaves weigh much less than gravel, so it’s possible to use the vacuum on them. However, you must test this out and make sure you have the vacuum switched to the lowest setting. Avoid using the vacuum on pebbled driveways, since pebbles are very light and may get suctioned up, which can damage the vacuum. If the vacuum starts to suction up the gravel, stop using it and remove the leaves by hand or carefully rake the area.