I have recently signed a contract for a property in a flood affected area in Brisbane but have discovered the below information.
Equitable access requirements for new development on flood effected land is as follows
1. Maximum 100mm inundation in a q20 event,
2. Maximum 300mm inundation in a q100 event
3. Depth velocity criteria for emergency exit for vehicle and pedestrian is 0.6.
The best results for the potential development site are follows.
1. Q20 256mm
2. Q100 = 386mm
3. DV 1.1
Would love to hear from anyone with any ideas or potential solutions for this site
MozalFreckleBlocked@freckleJoin Date: 2012Post Count: 1,681
Fish farming? aquatic center?TerrywParticipant@terrywJoin Date: 2001Post Count: 16,190SeanWilsonParticipant@seanwilsonJoin Date: 2013Post Count: 26
What do you mean by these numbers, that you are looking at 400mm inundation max if you are flooded?
Just build the house on stumps… As long as you are 100mm above the Q20 or Q100 flood levels you will typically be fine. Call me and I can talk to my certifier about it, or click on my sig and contact me through there.
You can definately still get stuff done on 'flood affected' sites though.
Thanks all for your responses.
Sean, I guess building on Stumps should be okay. The main concern is the Depth velocity ratio. The maximum allowed is 0.6M and for this property, its 1.1m. What this basically means is that is the height of flood water gets more than 0.6m, it will knock you over with the force.
Any further advice/comments ?RPIParticipant@rpiJoin Date: 2012Post Count: 308
What sort of development, this will greatly change the outcome.
In an estate development you can use the roads to collect water, swales to catch it and detention pits to retain it. 400m block with a house on it is a very different story.
This is a 1000 sqm block near Toombul shopping centre and I was intending to build 4 pack townhouses on this property.RPIParticipant@rpiJoin Date: 2012Post Count: 308
Infor from floodwise report below.
Overland Flow Path
Minimum Ground Level (AHD) 2.8 m ARI (Years) %chance Level(AHD_)
Maximum Ground Level (AHD) 4.0 m 5 20% 3.7 m
Defined Flood Level (DFL) 5.0 m 20 5% 4.3 m
Defined Flood Level Source CREEK/WATERWAY 50 2% 4.6 m
Minimum Habitable Floor Level N/A 100 1% 5.0 m
Flooding may also occur from: STORM TIDE, OVERLAND FLOW