A lot of our fertile rural land is flood prone and different councils will have different policies regarding building within what is often referred to as the 1 in 100 year flood level. Essentially if you’re building a shed in a recognised flood prone area there are a few additional steps to complete that you may not have previously needed to do.
We shall use the methods applied by several councils on the NSW North Coast as an example on how things often work when it comes to building on flood prone land.
If your shed would normally be an exempt farm building under 200 m2 and, if it is being built within a flood prone area or the 1 in 100 year level then it requires a Development Application as well as a Flood Certificate from your shed supplier’s engineer or from a local engineer.
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 they decide if any additional toughening of the engineering is required 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.
If in any doubt, check with your local council. Your local shed supplier should also have an intimate knowledge on what needs to be done to build a shed in your local flood prone areas. Effectively, in flood zones there is no such thing as an exempt shed.