Here we shall use the methods applied by several councils on the NSW North Coast as a guide on how things often work and what to expect when looking to build a shed in Flood prone areas.
Sheds being built within a flood prone area or the 1 in 100 year level usually require a Development Application as well as a Flood Certificate from your shed supplier’s engineer or from a local engineer. This includes Farm Sheds that are often classed as Exempt Development…in flood prone land they often require a DA still.
For a Flood Certificate the engineers look at historical and projected flood data and compare it to the engineering and where you will place the shed and decide if any additional toughening of the engineering is required or not to ensure that shed is likely to withstand inundation and impact from debris during a flood.
Generally all sheds above garden shed size in flood prone areas require DA approval.
Your local shed supplier should have an intimate knowledge on what needs to be done to build a shed in your local flood prone areas.