The sandbags found in the Chunnel were placed there by DelDot. They were used to locate a gas line in preparation for the replacement of the culvert. No details available regarding said replacement. We have been granted permission to remove the sandbags.
If you're willing to help with the removal of the sandbags please visit this link and add your name to the list via a comment on the forums, thanks: http://trailspinners.org/forum/chunnel-sandbag-removal
UPDATE: If we find the bridge that is missing from the White Clay side we have permission to replace it. Someone please go find that bridge or build a suitable replacement.