Adelaide Hills Flood Management DPA
Current best practice in terms of flood management is to minimise threats to life and property by restricting development on land subject to inundation by a 1-in-100 year flood. While this can be applied relatively easily to a 'greenfield' site, the imposition of this policy within existing townships is not as simple.
The situation in the Adelaide Hills is further complicated by the fact that, historically, townships were usually located alongside creeks and rivers to ensure a reliable water supply and to take advantage of productive alluvial soil. Because of this, several townships or parts of townships are situated on land which is subject to flooding. It has only been in more recent times that the extent of the 1-in-100 year flood has become apparent and has been able to be accurately mapped.
With these issues in mind, URPS was commissioned to prepare a Flood Management DPA which would strike a balance between protecting life and property while also allowing appropriate development within flood prone areas. This was achieved by restricting land division and higher density housing on flood prone land while at the same time introducing guidelines for additions to dwellings and outbuildings. A particular challenge was the drafting of policies to control building activities such as fences, garden sheds and retaining walls which do not normally require development approval.