A portable ground deployed flood barrier for the protection of a structure against tidal or ground surface flooding provides a lower cylindrical ground tube placed on the ground against the structure base, an upper cylindrical float tube and an intermediate sheet material attaching between the ground tube and the float tube which is presented as folded but readily spread vertically as the flood waters rise, causing the float tube to rise to the water level while leaving the ground tube in contact with the ground surface forming a water proof barrier for the structure against the flood waters.