Just spoke to Benz he is in BR and Talking to the Engineer in charge of fixing the canal wall its around 40 st for about 300 ft it took him awhile to convince the corps that his ideacould work Sounds crazy but think outside the box here
Lengths of sail cloth reenforced with rods of some sort that is say 20 to 30 feet longer than the hole connected to two winches than flown like a kite downstream amd winched into place to slow the water down just enough to allow the sandbags to be dropped in
This is not a joke iwill try to call him back to see if he is going to be hellicoptered in to town