_____             surface area contact


The above figures are approximate! The figures are calculated based on non-flexible material such as steel....because flexible barriers bow out they will contact more ground surface, accept more water and therefore will weigh more than the figures stated above.

While ground surface contact and volume/weight of water is much higher for rectangular barriers, it may not be necessary to completely fill the barriers with water.....the decision to do so will depend upon the judgement of those setting up the barrier considering the anticipated height and velocity of the on-coming floodwaters; in many cases barriers can for example, be filled 2/3 their stated height or less with water, with the balance of the barrier filled with air.

Air filling can be accomplished from a variety of sources....leaf blower, shop vac even a hair dryer (separate heat and fan switches with the heat shut off). The advantage of partial air filling is that the target barrier height can be achieved much more rapidly than by filling solely from a garden hose.

Do not exceed recommended height for the barriers regardless of whether filled by air or water! 


surface area contact

                                                                                                   Ground Surface Contact           Volume/cubic Inches            Weight of Water                           

                                                                                                                                                                                                               (in pounds) 

12 inch high cylindrical barrier @ 12.5 ft. length                                 4-5 inches                              16,971                                      613

12 inch high Rapid Barrier @ 12.5 ft. length                                          18 inches                              32,400                                   1,420

20 inch high cylindrical barrier @ 25 ft. length                                     6-7 inches                              94,248                                   3,406

20 inch high Rapid Barrier @ 25 ft. length                                             28 inches                             180,000                                   6,502

42 inch high cylindrical barrier @ 25 ft. length                                     16-18 inches                         415,800                                15,021

42 inch high Rapid Barrier @ 25 ft. length                                                 63 inches                          793,800                                28,677

Ground Surface/Volume Comparisons


Cylindrical Barriers and the Rapid Barrier System