Engineering and design making flood prone housing developments viable
LONDON: Advanced engineering and design are now making flood prone housing developments viable.
Commercial property developer Julian Ackad reckons he knows precisely the cost of how to build to meet the impact of the next big flood when it hits Lismore.
It’s $360,000.
The price tag includes engineering and design solutions he hopes will fortify a new service station his company has built in one of the lowest lying areas of a city smashed by flooding in 2022.
The managing director of Spectrum Retail Group said flood-proofing the service station would eat into the development’s profitability, but would ultimately make it a more attractive prospect to any future investors.
“I take the view that you are not just going to shift the whole town to another place,” Mr Ackad said.
“We need to all work on how we live in a safe way knowing that floods can, and will, come.
“We think it’s a very defensive asset, and is one example of a development that is very flood resilient.”
The service station site is located within the bounds of three water courses, all of which broke their banks during flooding that hit the Northern Rivers.
At the flood peak, the development site was 14 metres under water.
During the next flood event, water will flow into pits on the site and trigger automated concrete barriers that will pop up to protect the front of the shop from the impact of fast-moving water and debris.
Staggered slab concrete fencing around the site will also help slow the flow of water.
Staff will be trained to pull down metal shutters to protect the building’s windows and evacuate as soon as the city’s flood-warning system sounds.
As a safeguard, a flood refuge has been installed on the roof of the building.
With modern fuel tanks designed to prevent any water contamination, Mr Ackad said the service station could be open again within a day of floodwaters receding.
It is a vastly different scenario to the impact of the last floods on a number of the city’s service stations, which remain closed two years after the event.
“It’s responsible, it’s safer, people can feel as though this is the modern construction standard that commercial developers need to take in Lismore,” Mr Ackad said.
Educator John Stewart is another entrepreneur investing in the solutions needed to develop on the flood plain.
Mr Stewart is converting one of the oldest and largest buildings in Lismore’s central business district into a campus of his independent Living School.
The Brown and Jolly building has been inundated by many floods since it was built in 1900, with some of its original design features acknowledging the need to let light and air into its cavernous interior.
Mr Stewart and his architect Nici Long have embraced the inevitable flow of floodwaters through the building.
“We thought, let’s use this building to be part of the flood process because floods are horrible, traumatic, devastating but they also bring people together,” Mr Stewart said.
The design features hard surfaces throughout the ground floor that can be hosed out after a flood into an indoor rainforest.
The area will utilise the existing concrete slab and hardwood flooring originally cut from the region’s Big Scrub timbers.
Ms Long said opening the roof above the rainforest to sunlight would also allow the entire area to be decontaminated by natural ultraviolet rays.
Learning spaces and equipment that cannot get wet will be upstairs above the record flood height set in 2022, which continues to be regarded as a one-in-500-year event.
Ms Long said the last flood provided a blueprint for the parts of the building that could be retained, including the rainforest timbers and steel beams.
“We’re just trying to find passive systems, working with the environment instead of against it,” she said.
“A third of the world lives with flooding, where it’s an annual event, and they live with it in a sympathetic way.”
