Flood planning for apartment buildings

To start with, bring your community together and ask whether there are people who can help because you may not know they are living there until you ask; you’d be surprised what knowledge you have within your ranks.

Then reach out to skilled people who have been through a flood event and have some experience. As individuals though, they have to be cautious because they don’t want to take on liability, so at some point you may have to engage a professional such as a structural engineer.

Consider joining Resilient Kurilpa Apartments Network Facebook Group to reach out to our broader apartment community.

How can you get the Body Corporate to justify the cost of things like generators, pumps, and flood barriers, particularly if your building only experienced minor flooding and only lost power for a couple of days in the last flood?

1. Share Resilient Kurilpa’s short film on preparing apartment communities for flood events.

2. Get informed about flood awareness. Use the Brisbane City Council Flood Awareness Map. It’s going to give you at least a 1% annual exceedance expectation probability. So, in terms of risk management, as long as you’ve got a starting point for what level you’re trying to deal with, then you can have the conversation with the Body Corporate.

3. Refer your committee to the Kurilpa Flood Library to learn about the height and extent of past floods such as the 1841 flood, the 1893 flood, and the 1974 flood. As well as projections of future floods disasters.

4. Discuss the likelihood and risks your apartment community are comfortable with. It wouldn’t be hard for a 2011 flood event to happen again, which was a metre higher than one 2022 flood. In 2011, sewers stopped working and some apartments lost power for 10 days. The estimated damage to Riverpoint apartments was $1 million. People with low mobility were trapped in the seventh story for a week. So there was a great cost in terms of psychological impacts.

5. Discuss the financial benefits of mitigating your risks earlier. Different buildings have different impacts and in the case of Riverpoint, they raised money from the community and had some insurance wins and reinvested that money back into the property so they don’t have to deal with those issues of stress and loss in the future.

   Each building is different so residents need to understand their building and what’s at risk, then they can formulate a plan of how they’re going to mitigate those risks and put some percentages of likelihood against those to establish a funding plan.

6. Ask a member of another body corporate to share their flood mitigation experiences in your next body corporate meeting.

For example, which ones are safe? Does being on the hospital grid mean outages won’t affect me?

It’s been difficult to get information out of Energex, but we of know that Montague Road is more resilient than Riverside Drive from Dornoch Terrace. Being on a hospital circuit may not mean you are less vulnerable because there are transformers in various locations. Energex will close down a circuit based on the lowest point in that circuit, i.e. the point that is most at risk of shorting out. But the supply for Dornoch Terrace comes down very close to the ferry, which may mean that circuit will be turned off, but there needs to  be more information supplied.

Engage your fellow residents. The body corporate acts on behalf of residents, so they are accountable to the residents. Share Resilient Kurilpa’s short film to help people understand the importance of flood planning.

Organise a discussion for residents and the body corporate committee around what the issues are and what you could do to mitigate them.

If they’re not willing to act there are measures you can take. You can vote them out and create a new body corporate. There is a formal complaints process through the Commissioner for Body Corporates if you feel the body corporate are not acting in the interests of the residents or have not acted appropriately.

Individuals have unique risks in flood events. In some scenarios, residents have opted to moved to protect their safety and health.

The Kurilpa Flood Library is a good starting point. There are great resources and links there. Get familiar with local knowledge and try to understand the risks first.

Understanding your building and how it performs or reacts to a flood is key. Just don’t go too fast. People have invested in what they think are the appropriate measures to mitigate flooding and it’s not been a good investment.

The two events were very different. 2011 was an alluvial flood event, while 2022 was more about local rainfall, which affected stormwater drains creating a double whammy; that’s why it happened so quickly.

The 1974 flood was caused by two cyclones in one week over a wide area. That’s part of the problem with forecasting based on historical events. Every flood has variables and they are becoming harder to predict. What forecasters focus on is “What is the river doing in this event? How high is it? How fast is it rising? What is the forecast out where it’s going?” Some residents may choose not to look at historical data, but rather focus on what the river is doing.

On the Council’s Flood Awareness Map you can turn on Overland Flow Mapping, which shows an overland flow path that runs down the valley between Boundary Road and Hardgrave Road and goes through just behind the shops at the intersection of Vulture and Boundary Streets. There are a number of streets that cross it where the streets are higher than the houses. There is a stormwater drain that goes through there and when the drain’s capacity is exceeded the water goes overland. The houses in that area are affected by overland flow, which is a flash-flooding event in the local catchments and has nothing to do with the river.

Paul Granville’s article on the Resilient Kurilpa blog traces all the different water courses, creeks, gullies, and swamps across the peninsula.