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Interior of home that has been retrofitted to be resilient to flooding

Retrofitting your home for flood resilience

  • 7:00pm - 8:30pm
  • Online
    Australia

  • Free – registration required
05/19/2021 7:00pm 05/19/2021 8:30pm Australia/Melbourne Retrofitting your home for flood resilience Online Melbourne Water [email protected]

Event Details

We held a free online information session to find out more about the new Flood Resilient Guide to Retrofitting Your Home.

Man and woman bail out flooded home with buckets
Image credit: Penny Stephens, The Age

This easy-to-follow guide has been developed by Melbourne Water for homeowners who have experienced flooding and want to reduce the impacts of future flood events. Through retrofitting, it’s possible to save costs in the long term by avoiding temporary relocation and repairs.

This webinar's purpose was to help you:

  • Understand what a flood resilient home is
  • Find out the different approaches to retrofitting, including some examples of flood resilient homes
  • Find out the issues relating to home insurance and flooding and what you need to discuss with your insurance agency
  • Find out what steps you can take to prepare for flooding and how to find your local flood information 
     

 

Attendees also have an opportunity to ask industry and government experts questions about retrofitting your home and preparing for flooding:

Questions about the Elster Creek Catchment partnership and flood management in Greater Melbourne

Q: In his presentation James showed how the minimum acceptable height of houses located in flood-prone areas in Brisbane increased from nine to 11 metres over a couple of years. Will the minimum acceptable height for renovations and new builds also be assessed and/or increased in the catchment?

A: Fortunately in the Port Phillip Bay area we are not subject to such extreme tides or potential flood levels as the Brisbane area, but in a changing climate and increasingly urbanised city we understand that flood levels and flood extents are predicted to change.

The minimum floor level for renovations is dependent on the size of the extension, and these floor levels are specified in the DELWP Guidelines for Building in Flood-prone Areas. For new builds, Melbourne Water sets the floor levels which are based on the most recent flood modelling data for each catchment. This includes freeboard above the flood level. The data used is regularly updated through Melbourne Water’s ongoing flood information program. This enables tangible flood damages to buildings and their contents to be avoided or reduced.

Q: What influence can Melbourne Water have on Victorian State planning laws so that new developments, both small and large, in the Elster Creek Catchment and other parts of Melbourne are constructed according to water sensitive urban design principles (i.e. permeable surfaces, minimum percentage of unsealed surfaces and retention basins, etc.)?

A: As the question suggests, provisions for water sensitive urban design in development are set by the Victorian State Government, but Melbourne Water has input into these provisions in various ways.

In key major precinct developments Melbourne Water is leading stormwater harvesting and WSUD opportunities with partners, and across the region directly invests and provides partner grants to help to embed water sensitive urban design into new developments. Melbourne Water has had input into the update of the Precinct Structure Planning (PSP) guidelines due for release soon. Those updated guidelines will improve stormwater outcomes further by setting higher standards of design and development in relation to climate resilience and adaptation, including integrated water management practices, and consideration of climate change impacts on drainage systems. We also engage with the Victorian Planning Authority early in the planning process for specific developments to help identify opportunities to achieve better outcomes for water and the environment, through integrated water management. EPA released the Draft urban stormwater management guidance in late 2020 for industry feedback. The guidance document introduces flow and infiltration standards for new development, and Melbourne Water has been working with the EPA on this release.

 

At a more local scale, there are a number of actions within the Elster Creek Flood Management Plan that relate to making sure this balance is met:

Action 5 – Investigate incentives or funding mechanisms for landholders to reduce impacts on local catchment by reducing runoff and increasing permeability. Action 7 – Seek authorisation from the minister of planning to prepare a planning scheme amendment to update the extent of the Special Building Overlay (SBO) to reflect more recent flood mapping data within Glen Eira. Action 9 – Establish a catchment baseline for permeability and set targets to increase permeability in both the private and public realm. Include consideration of future development into permeability target setting.

Q: What are Melbourne Water’s most current flood levels for the catchment?

A: Melbourne Water provide the 1% Annual Exceedance Probability (AEP, a 1 in 100 year event in the old language) for the whole of the greater Melbourne region, and this information is regularly updated on a rolling basis.

Flood information at a more granular level (e.g. 2% AEP, 5% AEP) can be developed by either councils or Melbourne Water, and organisations work closely together to prioritise updating that flood information. Like Melbourne Water’s region-wide modelling, local catchment modelling is undertaken on a regular and rolling basis, with priorities usually determined by rate of development or other local-scale changes to the area. All that information comes together periodically in the development overlays administered by councils, which consider both Melbourne Water and council mapping.

Within the Elster Creek Catchment, the most recent overlays for the councils within the catchment include: Port Phillip in 2016, Bayside in 2019, and Kingston in 2005. Glen Eira has recently updated flood information for the whole municipality and an update to the planning scheme will follow. It is important to note, however, that there is more current flood information for some local catchments within municipalities as their own flood modelling programs continue. 

To complement the information ‘owned’ by the different agencies, however, there is also a deliverable in the Elster Creek Flood Management Plan to create a flood baseline and flood risk reduction targets for the whole catchment, cutting across council boundaries. This resource will help the community access the most up-to-date flood information more easily. The due date for that deliverable is end of next financial year (June 2022), and when ready will be available through council and MW channels.

Q: Has the Elster Creek Catchment partnership considered establishing a council flood program for homeowners in areas that are flood-prone like the one that James mentioned that Brisbane City Council has? Have you considered a CRC study of Elwood with regards to a redesign of local streets and houses (e.g. permeable laneways)?

A: Flood management responsibilities in Melbourne differ to the arrangements in Brisbane, making investment in individual properties by agencies a different proposition. From Melbourne Water’s perspective, flood mitigation programs are a direct outcome of legislative obligations to minimise flooding and flood damage outlined in the Water Act (1989) Section 202. The delivery of programs must be both efficient and prudent and consider a range of criteria to decide if a flood mitigation solution is feasible. One of the criteria is that the flood solution must provide value to multiple beneficiaries and not an individual household, as such the program being delivered in Brisbane would not meet Melbourne Water’s criteria.

That said, Melbourne Water is seeking to expand the current program to identify new strategies and flood solutions that may be more effective in some locations. This involves a more flexible innovative approach to flood mitigation that addresses the increasing challenge of flooding from climate change and urban development.

The Elster Creek catchment partners are investigating how to increase permeability within the catchment following research led by City of Port Phillip into options and relative effectiveness for different conditions and scales across that municipality. That research is feeding into setting permeability targets for the whole catchment, being led by Glen Eira in the coming year.

Q: Good planning should surely include reduced upstream high-density development resulting in more stormwater run-off for flood-prone areas. Has there been any consideration for this across broader metropolitan Melbourne.

A: The referrals process for new developments – where developers and other builders are required to submit designs for review and comply with conditions set by authorities including councils and Melbourne Water – is in place to manage exactly this kind of issue. The criteria for new development is no net increase in flood effects downstream, and given councils and Melbourne Water will be impacted by issues of flood management if that criteria is not met we collectively make every effort to be clear in those conditions. In practice any new impervious area will change the flow of water and some impacts cannot be predicted, so we work with the best available information and set development conditions to balance supporting a growing city and mitigating flood risk.

Increasing agency experience with overseeing the implementation of Clause 53.18 in the Victorian Planning Provisions – introduced in 2018 to “ensure that stormwater in urban development, including retention and reuse, is managed to mitigate the impacts of stormwater on the environment, property and public safety…” – new stormwater volume management guidelines being developed by the EPA, and regular updating of flood information across catchments are all mechanisms to support getting that balance right across our region.

 

 

At a more local scale, there are a number of actions within the Elster Creek Flood Management Plan that relate to making sure this balance is met:

 

 

 

Questions to Sarah Stephen (SES)

Q: Does the SES work with local government to develop their flood plans, including evacuation points, immediate assistance for evacuees, etc.?

A: The SES manages the development of the municipal emergency response plans for councils, which includes plans for managing flood emergencies. SES also input information into Flood Management Plans developed by councils and Melbourne Water on local flood hotspots and particular challenges within local communities.

The SES have also developed local flood guides for the community, and have a program of proactive doorknocking in areas that are prone to flooding to educate and increase the community’s preparedness for flood.

(For the Elster Creek Catchment, Vic SES publish Local Flood Guides for Elwood and Glen Eira.)

Questions to James Davidson (JDA CO)

Q: Is James aware of other cities and/or state have adopted similar models to The Flood Resilient Homes Program?

A: Homeowner subsidy for retrofitting works has only been rolled out in the Brisbane city council area at this stage, but a guide has also been produced for Gold Coast, Logan, and Bundaberg Council areas.

Port Macquarie and Resilience NSW are working on a similar initiative, but that program is still in its infancy.

Q: Re: retrofitting a home where the original rooms are double brick and the newer section is on a slab, there are numerous vents under floor, plus entries for pipes for hydronic heating. Water entered from beneath both in 1989 (to a few centimeters) and 2011 (near the top of our gumboots). Are there any suggestions on how to cover the many gaps under floor levels in homes?

A: Sarah: Sandbags are a good option. You also need to make sure that you cover all the little holes, not just the larger ones. For example, in the toilet place a sandbag in a plastic bag to prevent sewage backflow, place a sandbag over the shower drain, and against vents outside the home.

James: In new builds, it is the builder’s job to make the sure the vents are at the right height and any other inlet points are covered; check that they have done this.

Also a good idea to install non-return valves at certain points that need to let water out but not in.

But overall it may be better to protect the whole home and dry proof around the edge and the outside walls. This prevents water coming into the property to begin with. Check out the Flood Resilient Homes Guide for ideas on how you can do this.

Q: What are your top tips for renters to prepare their homes for flooding?

James: Any structural changes to the home rely on a conversation between renters and landlord/agency, which can be tricky. Easiest step is for renters to ensure they have the appropriate contents insurance, and check the owners have appropriate insurance for flood damage for the house itself (to help expedite repairs if necessary).

Webinar participant: Regarding retrofitting, we have explored at more temporary measures for flood proofing our home, like sealing tapes around floors and windows, fitting covers over under-floor air vents, and utilising self-inflating flood sacks. These measures are temporary but can be effective and are much cheaper than more permanent measures.

Questions to Tom Davies (ICA)

Q: Do people who own homes in flood-prone areas have any recourse with regards to increasing insurance premiums when new builds in the area are constructed in a way that reduces permeability and increases water runoff and therefore the risk of flooding in the area?

Q: What are your top tips for making sure your insurance is adequate for flooding?

A: Know your risk. Don’t buy a home in a flood prone area. Make an emergency evacuation plan (refer to SES information). Look at what you can do to retrofit your home. Have a conversation with your insurer to see about discounts on premiums if you’ve retrofitted.

Finally, don’t necessarily rely on finished floor levels as detailed on your house plans. They may be incorrect. Floor level surveys can also assist to establish actual levels and enable you to prepare better.

Who is the webinar for?

This session was designed for anyone with an interest in flood-resilient design, and especially people living in and around the Elster Creek Catchment in properties prone to flooding. If you live in the cities of Bayside, Glen Eira, Kingston or Port Phillip, your home may be in the flood-prone Elster Creek Catchment, which has always been prone to flooding. Climate change and increasing urban development will add to these challenges, with more severe and frequent storms and more hard surfaces like roofs and roads generating more stormwater runoff.

For an indication of whether your property has a high flood risk, see if your property has a Special Building Overlay by searching for your address on the VicPlan website. However, flooding is a complex issue and properties outside these areas may be liable to flooding now or in the future.

Presenters

James Davidson
Principal Architect, JDA Co and co-author of the Flood Resilient Guide to Retrofitting Your Home

James Davidson has lectured worldwide and has run studio, urban and residential design workshops in the Netherlands, UK and the USA. In addition to being the principal at JDA, James holds a Doctorate in Architecture with a primary focus on architectural anthropology, which he continues to develop in JDA’s practice work. He is also a previous director of Emergency Architects Australia, where he led their 2011 Queensland Floods relief project.

Over the course of the last decade James has become Australia’s leading flood-resilience architect. He has written the Flood Resilient Building Guidance for Queensland Homes for the Queensland State Government, the Flood Resilient Home Building Design Guideline for the Gold Coast City Council and is currently managing the roll out of the Flood Resilient Homes Program for the Brisbane City Council, which is the largest flood resilience built environment project to date in Australia.

Tom Davies
Climate Change Special Advisor, Insurance Council of Australia

Tom Davies has a special interest in transforming the economy and society to one that is ecologically sustainable. Having worked across industry and consulting Tom is now leading the Special Risks, Climate Change for the Insurance Council of Australia and is charged with developing and implementing a "Climate Change Action" strategy on behalf of the Insurance Industry. The role draws upon the insurance industry's expertise and resources to contribute focused and coordinated action to address climate change.

The Insurance Council of Australia (ICA) is the representative body of the general insurance industry in Australia. Its members represent approximately 95 percent of total premium income written by private sector general insurers. Insurance Council members, both insurers and reinsurers, are a significant part of the financial services system. The ICA has established a Climate Change Action Committee and a role to implement a strategy on behalf of industry.

Sarah Stephen
Acting Community Resilience Coordinator, Victoria State Emergency Service

Sarah Stephen has been working within the Emergency Management sector for over seven years – across a range of organisations. As a Community Resilience Coordinator with Victoria State Emergency Service, she works in a team that collaborates with VICSES Units, local councils, community members and other stakeholders to support communities to prepare for, respond to and recover from emergency events.

This free information session is brought you by Melbourne Water and the cities of Bayside, Glen Eira, Kingston and Port Phillip. It is part of a holistic approach to reducing flood risk in Elster Creek Catchment through the collaborative implementation of the Elster Creek Catchment Flood Management Plan.