Thank you for providing your feedback and telling us your experiences.
We wanted to understand more about our community’s experience with flooding and rising water levels. Your experiences and feedback are being measured against the Bureau of Meteorology's historical rainfall data to better understand what weather patterns have the most significant impact on our city.
Council is also in the final stages of developing flood maps for the municipality. Your experiences will provide further valuable information to support this.
Climate change is having an impact on Victoria’s rainfall levels.
Flooding and rising water levels are a natural occurrence
across Victoria as a result of this, and all Councils have a role to play in building
their community's resilience. This role is shared with water authorities,
emergency services and other government bodies.
Inner-city areas like Yarra tend to be prone to flooding and rising water levels as water can’t be absorbed into the ground easily and the topography of the area limits the way stormwater can move overland. This impacts the way our city develops, future infrastructure needs and how public spaces are designed.
Over the last few years, Yarra City Council has undertaken the following work to build Yarra’s resilience against flooding. This includes:
- maintaining the existing drainage network
- undertaking periodic inspections
- regularly cleaning pits and pipes
- proactive planning of capital or renewal work
- monitoring rainfall data and undertaking flood analysis
- boosting community preparedness through education
- identifying and upgrading critical drainage assets
As an additional preventative measure, we’re looking to implement planning controls that will ensure future developments are better designed to avoid the impacts of overflow in our stormwater network created during a severe storm.
These will be informed by a series of flood maps that are being finalised in partnership with Melbourne Water and guided by the best practice approach benchmarked against other Councils.
What is flooding?
Flooding and rising water levels are a natural occurrence across Victoria and all Councils have a role to play in building their community's resilience. This is in partnership with water authorities, emergency services and other government bodies.
Flooding can be influenced by a number of factors including;
- severe rain events which are being amplified by climate change
- land topography
- capacity of the drainage system
- the extent that water can be absorbed into the ground
In a Council context, flooding is defined as a natural yet persistent gathering of stormwater that disturbs the intended use of infrastructure and properties.
In Yarra when we discuss flooding it most often refers to overland flow flooding. Find out about overland flow flooding and the other types of flooding below.
Overland flow is run-off that travels over the land during heavy rainfall events.
Overland flow can be unpredictable because it is affected by localised rainfall and urban features such as stormwater pipes, roads, fences, walls and other structures. The actual depth and impact of overland flow varies depending on local conditions, but it generally occurs quickly and for short durations.
Creek flooding happens when intense rain falls over a creek catchment. Run-off from houses and streets also contributes to creek flooding. The combination of heavy rainfall, run-off and the existing water in the creek causes creek levels to rise.
River flooding happens when widespread, prolonged rain falls over the catchment of a river. As the river channel reaches capacity, excess water flows over its banks causing flooding. River flooding downstream can occur hours or days after the rainfall has finished. River flooding may coincide or exacerbate flooding in adjacent creeks and tributaries and may itself be exacerbated by higher than normal high tide conditions.
Storm tide flooding happens when a storm surge creates higher than normal sea levels. A storm surge is caused when a low-pressure system or strong onshore winds force sea levels to rise above normal levels. The impact of a storm tide or storm surge is increased during high tides and king tides and can affect low-lying areas close to tidal waterways and foreshores.
Tidal flooding is the temporary inundation of low-lying areas and streets during high tide events, such as at full and new moons. The highest tides of the year may be known as king tides. Areas connected to the foreshore and tide-affected areas of the river, tidal creeks and other waterways are susceptible.
