What is a voluntary house raising: As the title implies it is the voluntary house raising of property in low flood hazard areas of the floodplain. House raising typically involves using hydraulic jacks and beams to raise a house typically a few meters off its foundations and allowing a new non-liveable area to be built underneath from which the house now sits on. The purpose of voluntary house raising is to reduce flood related damages to that property and as such reduce the stress and post trauma of flooding (DIPNR, 2005).
Improves community access and recreational use:
Voluntary house raising does not improve community access and recreational use. Why? The property that is raised is private property and located on private land and as such creates no improvement to community access and recreational use.
Does not disadvantage individual members of the community:
Voluntary house raising may disadvantage individual members of the community. Why? Voluntary house raising in typical construction methodologies may limit access to mobility impaired individuals as stairs are utilised to get to the new occupiable floor level. In addition, the raising of properties may cause neighbourhood tensions as one property is raised potentially reducing the views of another property.
Provides safety to the community during flooding:
Voluntary house raising may provide safety to the community during flooding. Why? The properties that are raised particularly in flash flood environments may create a refuge for vulnerable individuals if designed accordingly. Generally however, voluntary house raising is undertaken to protect property damages and not people, and should be treated that way during emergency management responses as fires can occur, the utilities generally cease operation, and vermin enter properties creating potentially life threatening situations. As a result, they can provide a false sense of security and increase risk to life.
Raises community awareness and understanding of the local flood risk:
Voluntary house raising may improve the community awareness and understanding of the local flood risk. Why? In the short term the occupants and nearby residents are generally reminded of the potential flood heights in the local community however, over the longer term this may be forgotten.
Does not threaten local plants and animals and their habitat:
Voluntary house raising does not cause negative environmental and ecological impacts. Why? The raising of a property generally does not threaten local plants and animals as the works are usually within the footprint of the existing dwelling.
Does not cause water quality issues:
Voluntary house raising generally does not cause negative water quality impacts. Why? The raising of a property generally does not adversely affect the nearby stream or rivers water quality as the works are undertaken with strict building controls.
Initial Costs (i.e design/construction) require minimal council expenditure:
Voluntary house raising generally has a minor initial costs to council Why? The house raising of a single property typically costs around $60,000 to $100,000. Of this Council and the NSW State Government may pay a portion. Raising homes with slab-on-ground construction can however, can skew costs significantly as lifting methodologies become more complicated as either the entire slab is lifted or the house is detached from the slab and lifted. Sometimes if this is the case, it may be more economically feasible to demolish the house or raise the floor within the house, moving the living space to an upper story.
Requires minimal ongoing council expenditure after implementation:
Voluntary house raising requires no ongoing costs to council. Why? The raised house is the responsibility of the property owner.
Reduces flood damages to the community:
Voluntary raising can reduce flood related annual average damages to the community. Why? The raising of flood prone houses when other alternatives are not feasible or justifiable can reduce the repetitive damages caused by flooding and as such can be economically justified in some cases.
Does not cause negative flood impacts to other areas (both upstream and downstream):
Voluntary house raising generally does not adverse impacts to other areas. Why? The property is usually raised within the footprint of the existing dwelling and as such has usually has no adverse impacts in comparison to the existing dwelling.
DIPNR (2005). Floodplain Development Manual: the management of flood liable land. NSW Department of Infrastructure, Planning and Natural Resources. Sydney, Australia.