The Use of Water Tanks for Fire Fighting in Australia
Because many parts of Australia are deemed to be fire-prone areas, Federal, State and local governments and local Rural Fire Authorities have mandated the inclusion of fire-fighting tanks in rural and semi-rural areas, according to the fire risk profile of each area. Mains water may not be available, as in rural areas, or even if available, may fail due to fire damage.
Building approvals in rural and semi-rural areas are dependent on meeting requirements for water storage for fire-fighting as outlined by their local council and rural fire authority. In Victoria, 10,000 litres is the minimum requirement for fire-fighting water storage, while in some areas of New South Wales it is 22,000 litres for a large rural lifestyle lot of ranging in size from 10,000 2m to more than 1 hectare. In Queensland on the Sunshine Coast, the minimum requirement for a semi-rural property is set at 20,000 litres for fire-fighting and 40,000 litres for household use.
Concrete and metal tanks are more appropriate for use as fire-fighting tanks, although polyethylene tanks may be considered as an alternate source of water provided they have approved fire protection. Tanks to be used for fire-fighting generally have larger outlets than tanks for normal garden or household use.
New Australian Standards (AS) for fire-fighting tanks were developed in 2012 and manufacturers of fire-fighting tanks must conform to these standards such as (AS) 2304-2011. One of these requirements is that special liners have to be used in fire-fighting tanks. Tank fittings should be metal and not plastic. Underground tanks should have an access hole of at least 200 mm which allows a tanker to refill straight from the tank.
Water storage sources used to fight fires are either “dedicated” (DWS) or “static” (SWS). Dedicated means that the water is only used for fire-fighting and therefore issues of water quality are not important. A static water source can be an additional rainwater tank for household use, a swimming pool or a dam. Landowners are usually asked to display a clearly visible sign at the entrance to their property, approved by their local fire authority, indicating what water source or sources they have and where it is located.
Water sources for fire-fighting need to be fast flowing and to have fittings which are both fire-resistant and able to be quickly connected or disconnected. For these reasons, fire-fighting tanks need a Storz fitting and Vortex plates or Vortex inhibitors. Storz fittings were invented by Carl August Guido Storz in Germany in 1882 and have interlocking hinges and flanges which enable fast and simple connection and disconnection and which provide a strong water-tight seal. They are used in most fire-fighting situations in Australia and internationally. In areas served by the Rural Fire Service in NSW, a Storz fitting of 65 mm must be fitted at the lowest suction point on the tank. In other areas of Australia, local fire authorities determine what size the Storz fitting should be.
Installing a Vortex inhibitor in the outlet of a water storage tank prevents the build-up of turbulence which would reduce the flow speed of the water. There are several different types of Vortex inhibitors and some tank manufacturers have developed their own.