Quick Dam Water Dams - 2.5" Height - Orange - 12 / Carton Water Dams quickly absorb and gel water, swelling to create a barrier to control leaks and spills. Compact, water-activated dams swell and gel when wet. They are lightweight, quick and easy to deploy. Each one expands to 2.5" high in minutes to contain, control and divert problem water. Long, continuous lengths are perfect for wraparound protection. Durable knit keeps inner gel contained. Water dams can be left in place for maintenance or discarded into regular trash.