What is a voluntary purchase: As the title implies it is the voluntary offering and purchasing of flood prone property in particularly hazardous locations, where it may not be feasible or economic to mitigate the effects of flooding. After a property has been purchased it is removed or demolished and the land is rezoned to a flood compatible use (DIPNR, 2005).
Improves community access and recreational use:
Voluntary purchase generally improves community access and recreational use. Why? The property that is bought and removed is now public land that may be suitable for walking, cycle paths, parks, sporting fields and more recently community gardens.
Does not disadvantage individual members of the community:
Voluntary purchase generally does not disadvantage individual members of the community. Why? As the title implies the property is purchased at an equitable price (priced without the impacts of flooding being considered) and only when it is voluntarily offered. However, some neighbourhoods may become disjointed as resident’s offer their houses for purchase while one individual in the middle does not.
Provides safety to the community during flooding:
Voluntary purchase increases safety to the community during flooding. Why? The properties that are identified for voluntary purchase are particularly vulnerable to high hazard flood flows. This can cause significant risk to life to both the residents and emergency management personnel that try to rescue the residents. In addition the purchased property can be utilised to store or convey water which can reduce flood impacts to other areas.
Raises community awareness and understanding of the local flood risk:
Voluntary purchase does not generally raise community awareness and understanding of the local flood risk. Why? In the short term the community may know why that property has been removed however, in the longer term the land is usually seen as its current use i.e. parkland and not as a flood reminder.
Does not threaten local plants and animals and their habitat:
Voluntary purchase generally does not cause negative environmental and ecological impacts. Why? The removal of a property can create opportunities for the re-establishment of riparian vegetation, which can improve habitat for local plant and animals.
Does not cause water quality issues:
Voluntary purchase does not generally have negative water quality impacts. Why? As noted above, the removal of a property can create opportunities for the re-establishment of riparian vegetation that can create a buffer for urban pollutants improving the water quality of the stream or river.
Initial Costs (i.e design/construction) require minimal council expenditure:
Voluntary purchase generally have major initial costs to council Why? The acquisition of a single property costs the market rate. If a whole street is deemed high hazard and eligible for voluntary purchase, then this can become a costly venture for Council if they all offer their properties for sale. The NSW state government generally provides some assistance for the purchase and demolition of properties built prior to 1984.
Requires minimal ongoing council expenditure after implementation:
Voluntary purchase requires minimal ongoing costs to council post demolition. Why? Maintenance generally involves up keep of the land i.e. mowing.
Reduces flood damages to the community:
Voluntary purchase reduces flood damages to the community. Why? The removal of a high hazard flood prone property reduces the repetitive damages caused by flooding to both the property that is removed, and surrounding properties both upstream and downstream.
Does not cause negative flood impacts to other areas (both upstream and downstream):
Voluntary purchase and the subsequent removal of the property has the potential to cause adverse flood impacts to other areas. Why? As the property is removed it can increase the speed at which floodwater travels to downstream areas. This occurs as the property is no longer there to obstruct and slow down floodwater. However, it must be noted that the removal of the property increases the flood storage area which can offset the floodwater flows.
DIPNR (2005). Floodplain Development Manual: the management of flood liable land. NSW Department of Infrastructure, Planning and Natural Resources. Sydney, Australia.