Inflatable dams made of rubber sheets were used for the regulation of rivers. For one span of the biggest inflatable dam 1700 m(2) rubber sheets were necessary. Depending on the waterlevel one or more woven materials are used as reinforcing material. The up to now used normal weirs are more expensive than the inflatable dams. One important objective of a research and development project is to elaborate material specifications for future rubber dam constructions. Standard specimens were removed from the top plate of the rubber sheets. Material tests were performed with regard to tensile strength, tearing resistance, ageing, compression set resistance to cold, resistance to ozone, hardness and abrasion resistance. A testing facility was designed for investigating the built-in condition of a rubber sheet used for an inflatable dam. With regard to the risks of possible vandalism, investigations on the resistance of rubber sheets to injuries caused by stabs and shots were performed.