Chapter 5 cont. Dams Inflatable rubber, or fabric and rubber, dams and tubes have been used for years as weirs to impound water for water supply and flood control. Inflatable dams were developed and first used in the 1950s in the Los Angeles area. They were typically inflated with water. Since that time, construction materials and control systems have been improved and features have been added, such as fins to reduce vibrations during overflow.
Air is now the preferred inflation medium.
The manufacturers report that there are about 1,900 of these dams worldwide, with 50 in the United States. Alameda County Water District's Rubber Dam No. 3 is a representative example of a modern inflatable dam. The dam impounds a 154 af reservoir for direct groundwater recharge and diverts flows into adjacent spreading grounds in former aggregate pits. The air-inflated dam is bolted to a reinforced concrete slab that was constructed across the stream channel.