Quite obviously the raised Archimede houses can take on any flood. Even when the flood rises beyond the shell's lower edges, the tightness of the envelope will keep the water out. In cases where the water level is expected to rise much higher, we recommend a style of stilts developed to extend out, allowing floatation to take over. For tsunami shelters, a breakaway system allows the entire house to float away, tethered to a chain anchored to the ground. In this manner, the house is more capable of dealing with the floating debris that could  impact the shelter negatively if it was fixed in one place.