To block an opening or surround a building, lay out a single length of tubing where you want to erect the flood barrier, and fill it with water.
If the water flow from your municipal water system is too low, or you're filling a large section of tubing, you can speed up the process by pumping pond water, pool water or even flood water into the tubing by using a pump.
Keep the water in by turning up the ends of the tubing. The ends don't need to be sealed, but they must be secured in the up-turned position.
Use heavy objects that don't float to keep the tube from rolling, sliding or shifting. These might include sandbags, concrete blocks or another section of tubing. On unpaved areas, you can drive stakes in the ground to keep the tubing in place. The tube can rest against a strong board placed across an opening.