For a survival shelter I have gone to a simple, cheap, and tough system that consists of circular storm pipe 1 meter round by 2.5 meters long and only $220 each. Set on a 4 degree angle on a hillside, with top end sealed and covered in earth. Simply slip in the open end, and wait for the fireworks to stop. I've used these pipes to put a road over a creek, and was impressed to see the contractor driving a 20 ton truck over them with only 300 mm of dirt on top. The contractor said they are so strong you could run 50 tons over them. It's the egg shell principle.
Offered by Darryl.
One could build a one person slanted tube with the top sticking barely out of the ground. Possibly on the side of a hill. Cap off the top with a inwardly opening hatch. At the last minute add in some supplies. Tie or strap them down to the bottom of this tube. Get in with extra clothes on to help act as padding. Sit at the bottom on your supplies with knees and/or feet against the other side and your back to the lowest side of the tube. A safety belt with a cushioned seat and back could be bolted to this lower side to hold the back of the body to the wall of the tube.
Offered by Mike.
Supplies in the back strapped down, heavy pad on the floor along with straps to the floor to hold me. Ride it out laying down. In the side of a hill above where I estimate water to accumulate/runoff. Cap on the outward end, opening inward and a shovel as part of the supplies. Just have one or more culvert's delivered and bury them by hand. Excuse for the culvert(s) is to dig a shallow water well.
Offered by Ron.
I desided to research this subject a little.Thompson Culvert have good info. I still think this might be a good solution if it was covered with a layer of
earth and waterproofed.
Offered by Liai.