Flood Bags absorb, contain and divert problem floodwater to help protect your property from the dangers of flooding. They activate when wet and require no sand. Each bag absorbs 4 gallons of water, swells to 32 lb. and expands up to 3-1/5" high in 10 minutes. This compact and lightweight flood control is quick and easy to deploy. Inner absorbent turns to gel and creates a barrier. Flat uniform shape allows easy stacking. Stack in brick and pyramid formation. Leave bags in place for ongoing protection. No additional tools or supplies are needed to set up this type of flood control. Bags are safe, nontoxic and nonhazardous. When you no longer need them, you can discards them into your regular trash.