Rubber dam hydraulics:
Hydraulic design of inflatable flexible membrane dams
by Hubert CHANSON (
M.E., ENSHM Grenoble, INSTN, PhD (Cant.), DEng (Qld), Eur.Ing., MIEAust., IAHR Member, 13th Arthur Ippen awardee
The University of Queensland, School of Civil Engineering, Brisbane QLD 4072, Autralia

Hydraulics of rubber dams


Rubber dams are long tubular-shaped fabrics placed across channels, streams and weir crest to raise the upstream water level when inflated. The membrane is a multi-layer fabric made of synthetic fibre which may be rubberised on one or both sides, and possibly coated with plastic film. The fabric is quite flexible and yet exhibits very large resistance characteristics. The inflatable flexible membrane dams (IFMD, or rubber dams) were developed in the early 1950s. In open channels, they are used to divert water for irrigation, for raising existing dams, for flood controls. Other applications include remedy measure to prevent dam overtopping and control of chemical spills in streams. Inflatable dams can be filled with water, air or both. The present trend suggests an increased use of air-filled membranes because they can be deflated or inflated more rapidly, and they are little affected by freezing conditions. Characteristic dimensions cover typically lengths of about 100 m with specially-made membranes up to 200-m wide, dam heights usually less than 5-m but some special designs might be up to
10-m high. The membrane is usually deflated for large overflows. It is however common practice to allow small spillages over the inflated dam. During overflows, vibrations might result from fluid-structure interactions (e.g. OGIHARA and MARAMATSU 1985), and the instabilities might damage and destroy the rubber membrane. Several failures were experienced (e.g. CHANSON 1996). In practice, a deflector (i.e. fin) is installed on the downstream face of the rubber dam to project the nappe away from the membrane, hence preventing rubber membrane vibrations.

Hydraulics of rubber dams

Overflow of inflated rubber dams is characterised by an accelerating nappe which adheres to the membrane wall. Hydrodynamic and fluid-structure instabilities may develop and must be avoided. Current design techniques include the installation of a fin (or deflector) in the upper quadrant of the rubber dam, to deflect the flow away from the flexible membrane wall. Laboratory experiments and theoretical calculations demonstrate that the optimum location of the deflector is 30 < f < 60 degrees (CHANSON 1998a,b). Further a proper ventilation of the nappe is essential (CHANSON 1996).
The hydraulic design of rubber dam is still embryonary because of the large number of intervening parameters and processes. In practice physical modelling is strongly recommended.

Detailed photographs

Photo No. 1 : Bedford weir (Qld, Australia) : 195-m long 1.45-m high rubber dam installed in 1997. Inspection of the inflated dam with deflector in 1997 (Courtesy of Queensland Rubber Company).
Photo No. 2 : Bedford weir (Qld, Australia). Overflow of the inflated rubber dam in 1998, view from downstream (Courtesy of Queensland Rubber Company).
Photo No. 3 : Tucombil weir (Nsw, Australia) : 61-m long, 1.8-m high water filled rubber dam installed in the 1980s and dimantled in the early 2000s. The weir was built on the Tucombil canal to prevent tidal effects (i.e. salt intrusion) between the Richmond river and the Evans river systems. During large flood events, the weir was to be deflated to reduce flooding effects in the Rcihmond river catchment. First rubber dam built by Queensland Rubber Company. Fully-inflated weir on 2 Nov. 1997.

Basic references

+ ANWAR, H.O. (1967). "Inflatable dams." Jl of Hyd. Div., ASCE, Vol. 93, No. HY3, pp. 99-119.
+ CHANSON, H. (1996). "Some Hydraulic Aspects during Overflow above Inflatable Flexible Membrane Dam." Report CH47/96, Dept. of Civil Engineering, University of Queensland, Australia, May, 60 pages (ISBN 0 86776 644 1). (PDF file at UQeSpaceOrder Hard Copy.
+ CHANSON, H. (1998). "Hydraulics of Rubber Dam Overflow : a Simple Design Approach." Proc. 13th Australasian Fluid Mech. Conf., Melbourne, Australia, 13-18 December, M.C. THOMPSON & K. HOURIGAN Ed., Vol. 1, pp. 255-258. (PDF file at UQeSpace)
+ OGIHARA, K., and MARAMATSU, T. (1985). "Rubber dam : Causes of Oscillation of Rubber Dams and Countermeasures." Proc. 21st IAHR Congress, Melbourne, Australia, pp. 600-604.


+  CHANSON, H. (1997). "A Review of the Overflow of Inflatable Flexible Membrane Dams." Aust. Civil/Struct. Engrg Trans., I.E.Aust., Vol. CE41, No.2 & 3, pp. 107-116 (ISSN 0819-0259). (PDF file at UQeSpace) (Download PDF file)
+ CHANSON, H. (1998). "Use of Rubber Dams for Flood Mitigation in Hong Kong. Discussion." Jl of Irrigation and Drainage Engrg., ASCE, Vol. 124, No. 3, pp. 181-182 (ISSN 0733-9437). (PDF file at UQeSpace) (Download PDF File)
+ CHANSON, H. (1999). "The Hydraulics of Open Channel Flows : An Introduction." Butterworth-Heinemann, Oxford, UK, 512 pages [ISBN 0 340 74067 1]
+ CHANSON, H. (2004). "The Hydraulics of Open Channel Flows : An Introduction." Butterworth-Heinemann, 2nd edition, Oxford, UK (ISBN 0 7506 5978 5).
+ CHANSON, H. (2006). "Minimum Specific Energy and Critical Flow Conditions in Open Channels." Journal of Irrigation and Drainage Engineering., ASCE, Vol. 132, No. 5, pp. 498-502 (doi:10.1061/(ASCE)0733-9437(2006)132:5(498)) (ISSN 0733-9437). (PDF file) (PDF file at UQeSpace). Closure: Journal of Irrigation and Drainage Engineering, ASCE, Vol. 134, No. 6, pp. 883-887 (DOI: 10.1061/(ASCE)0733-9437(2008)134:6(883)) (ISSN 0733-9437). (PDF file at UQeSpace).
+ CHANSON, H., and MONTES, J.S. (1998). "Overflow Characteristics of Circular Weirs : Effect of Inflow Conditions." Jl of Irrigation and Drainage Engrg., ASCE, Vol. 124, No. 3, pp. 152-162 (ISSN 0733-9437). (PDF file at UQeSpace)(download PDF file)
+ DAKSHINA MOORTHY, C.M., REDDY, J.N., and PLAUT, R.H. (1995). "Three-Dimensional Vibrations of Inflatable dams." Thin-Walled Struct., Vol. 21, pp. 291-306.
+ DUMONT, U. (1989). "The Use of Inflatable Weirs for Water Level Regulation." Intl Water Power & Dam Construction, Vol. 41, No. 10, Oct., pp. 44-46.
+ SHEPHERD, E.M., McKAY, F.A., and HODGENS, V.T. (1969). "The Fabridam Extension on Koombooloomba Dam of the Tully Falls Hydro-Electric Power Project." Jl Instn. of Eng., Australia, Vol. 41, pp. 1-7.
+ TAKASAKI, M. (1989). "The Omata Inflatable Weir, at the Kawarabi Hydro Scheme, Japan." Intl Water Power & Dam Construction, Vol. 41, No. 11, Nov., pp. 39-41.

Rubber dam manufacturers

Trelleborg Queensland Rubber (formerly Queensland Rubber Company) (Australia)  515 Zillmere Rd, Zillmere, Brisbane QLD 4034, Australia
Fax: (61 7) 32 63 49 12 Url:
Satujo (France)
Bridgestone (Japan)
Rubena (Czech)
Hydroconstruct (Austria)
Superior Dam LLC (USA)


Hubert CHANSON thanks the following people for their help : Professor C.J. APELT, Brisbane, Australia; Mr W.H.BOYCE, Brisbane, Australia; Queensland Rubber Company.


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Hubert CHANSON is a Professor in Civil Engineering, Hydraulic Engineering and Environmental Fluid Mechanics at the University of Queensland, Australia. His research interests include design of hydraulic structures, experimental investigations of two-phase flows, applied hydrodynamics, hydraulic engineering, water quality modelling, environmental fluid mechanics, estuarine processes and natural resources. He has been an active consultant for both governmental agencies and private organisations. His publication record includes over 620 international refereed papers and his work was cited over 3,700 times (WoS) to 6,300 times (Google Scholar) since 1990. Hubert Chanson is the author of several books : "Hydraulic Design of Stepped Cascades, Channels, Weirs and Spillways" (Pergamon, 1995), "Air Bubble Entrainment in Free-Surface Turbulent Shear Flows" (Academic Press, 1997), "The Hydraulics of Open Channel Flow : An Introduction" (Butterworth-Heinemann, 1st edition 1999, 2nd editon 2004), "The Hydraulics of Stepped Chutes and Spillways" (Balkema, 2001), "Environmental Hydraulics of Open Channel Flows" (Butterworth-Heinemann, 2004), "Applied Hydrodynamics: an Introduction of Ideal and Real Fluid Flows" (CRC Press, 2009), and "Tidal Bores, Aegir, Eagre, Mascaret, Pororoca: Theory And Observations" (World Scientific, 2011). He co-authored two further books "Fluid Mechanics for Ecologists" (IPC Press, 2002) and "Fluid Mechanics for Ecologists. Student Edition" (IPC, 2006). His textbook "The Hydraulics of Open Channel Flows : An Introduction" has already been translated into Spanish (McGraw-Hill Interamericana) and Chinese (Hydrology Bureau of Yellow River Conservancy Committee), and the second edition was published in 2004. In 2003, the IAHR presented him with the 13th Arthur Ippen Award for outstanding achievements in hydraulic engineering. The American Society of Civil Engineers, Environmental and Water Resources Institute (ASCE-EWRI) presented him with the 2004 award for the Best Practice paper in the Journal of Irrigation and Drainage Engineering ("Energy Dissipation and Air Entrainment in Stepped Storm Waterway" by Chanson and Toombes 2002). Hubert Chanson edited further several books : "Fluvial, Environmental and Coastal Developments in Hydraulic Engineering" (Mossa, Yasuda & Chanson 2004, Balkema), "Hydraulics. The Next Wave" (Chanson & Macintosh 2004, Engineers Australia), "Hydraulic Structures: a Challenge to Engineers and Researchers" (Matos & Chanson 2006, The University of Queensland), "Experiences and Challenges in Sewers: Measurements and Hydrodynamics" (Larrate & Chanson 2008, The University of Queensland), "Hydraulic Structures: Useful Water Harvesting Systems or Relics?" (Janssen & Chanson 2010, The University of Queensland), "Balance and Uncertainty: Water in a Changing World" (Valentine et al. 2011, Engineers Australia). He chaired the Organisation of the 34th IAHR World Congress held in Brisbane, Australia between 26 June and 1 July 2011. He chairs the Scientific Committee of the 5th IAHR International Symposium on Hydraulic Structures to be held in Brisbane in June 2014.
 His Internet home page is He also developed a gallery of photographs website {} that received more than 2,000 hits per month since inception.

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Applied Hydrodynamics Tidal bores Applied HydrodynamicsEnvironmental hydraulics of open channel flowHydraulics of open channel flow (2nd edition)The Hydraulics of Stepped Chutes and SpillwaysThe Hydraulics of Open Channel Flow: an IntroductionAir bubble entrainment in turbulent shear flowsHydraulic design of stepped cascades, channels, weirs and spillways  McGraw-Hill InteramericanaFluid Mechanics for Ecologists 13th Ippen award (IAHR)