Inflatable_rubber_dam
Inflatable rubber dams are cylindrical rubber fabrics placed across channels, streams and act as a weir or dam to raise the upstream water level when inflated. The membrane is a multi-layer fabric made of synthetic fibre (usually nylon) and rubberised on one or both sides. The fabric is flexible and yet exhibits good wear-resistance characteristics. A layer of stainless steel mesh or ceramic chips can be embedded in the surface layer to reduce or prevent vandal damage.
The inflatable flexible membrane dams (IFMD, rubber dams, tiger dam[1]) were developed in the 1950s by Norman M. Imbertson of the Los Angeles Department of Water and Power and were originally called fabridams.[2] They are installed in stream and river beds, generally being bolted into a concrete foundation. They are used to divert water for irrigation, temporarily raising existing dams, flood control, water retention for aquifer recharge, reducing or preventing salt water intrusion into fresh water areas, protect low-lying coastal areas from tidal flooding, enabling fish passage past diversion works, by deflation, and for sewage retention/separation during flood events.[3]
Inflatable dams can be filled with water, air or both. They typically span about 100 m, with dam heights usually less than 5 m. The membrane is usually deflated for large overflows, but it is common to have a small nappe over the inflated dam.[4]