Culverts, and head walls, require a lot of excavation, prior to installation. Excavation, of main arroyos, and waterways, requires a lot of preparation in the ground work before setting in the culvets,. Once culverts are set in place you must comact, the soil around the culverts, until the culverts, are completely covered. Then you must build the forms for the head walls, to accomodate the concrete pour. After the concrete pour you must strip the forms and backfill, and compact, the soils around the head walls,. After the compaction, is complete you can then add the surface cover to the new access drive way, for stability.
