Floods
How we manage floods
Glenorchy City Council has a flood early warning system for the Glenorchy CBD and surrounding area. During extreme weather events, this system will provide us with advanced warning of an impending flood and allow us to take action to minimise the impact of flooding from Humphreys Rivulet and Barossa Rivulet, which flow through the city centre.
Is my property in a flood-prone area?
Glenorchy has produced detailed maps based on the results of previous flood studies conducted for areas in teh city at risk of flooding
You can check your address to see if your property may be impacted by flooding using our interactive flood map, below.
You can also view a PDF version of our flood maps here (PDF – 52mb file)
Please note that this only provides an estimate give of the possible flood risk at your property. Your property may still be at risk of flooding in a severe event, even if it is not shown on the maps. If you are worried about the future flood risk at your property, you can also seek your own expert advice.
You can learn more about our flood studies and what it means for you by downloading our Flood Map Information and FAQs document, below (PDF):
How you can prepare for floods
To learn more about what you can do before, during and after floods, please visit the State Emergency Service website.
If a significant flood impacts our city, Council will implement its Emergency Management Plan and work with other emergency services to minimise the impacts as much as possible.
Glenorchy Flood studies
Flood studies and mapping help guide Council’s decisions around planning for new developments, identifying potential mitigations options and ways to improve stormwater infrastructure and community safety.
In 2021, Glenorchy City Council released updated flood maps for the entire urban area following months of research and modelling completed by Council engineers. This will allow Council to improve stormwater infrastructure, guide planning and prepare residents for future flood events. You can view the study below.
Flooding can affect most areas, but some areas carry a higher flood risk than others. To help you understand the degree of flood risk near your property or future development site, Glenorchy City Council has decided to map flood prone areas in the municipality. The mapping provides an indication of the likely flood prone areas only and should be read in conjunction with the Flood Maps Information and FAQ document.
This assessment of flood risk is based on past flooding records, expert opinion, as well as computer modelling about where flooding might occur in the future. We are using as much material as we currently have available, based on our current knowledge and resources. The flood study does not cover rural catchment areas.
Stormwater System Management Plan
Under the Urban Drainage Act 2013, Council must develop a Stormwater System Management Plan (SSMP) for the urban areas of its municipality.
The aim of the SSMP is to comprehensively address flood behaviours within the Glenorchy municipal area. The SSMP will work to foster a deep understanding of flood impacts in present and future scenarios and to align with the requirements of the Urban Drainage Act 2013.
View the SSMP and attachments below:
- GCC Stormwater System Management Plan – April 2024
- Appendix 1 – Critical Event Maps
- Appendix 2 – Inundation Depth Maps
- Appendix 3 – Inundation Hazard Maps
- Appendix 4 – Economic Impacts of Flooding Maps
- Appendix 5 – Flood Mitigation Option Maps
- Appendix 6 – Glenorchy CBD Stormwater System Management Plan
Stormwater
Stormwater generally means rainwater that runs off surfaces such as lawns, roads, roofs, car parks, driveways, patios and natural ground surfaces. Under the Urban Drainage Act 2013, runoff water is defined as water which has been concentrated by means of a drain, surface channel, subsoil drain or formed surface. This means runoff generated from natural surfaces, such as grassed lawns and gardens is not regulated by Tasmanian law.
Our role
We are responsible for maintaining all the public stormwater systems in the municipal area, including public stormwater mains, manholes and pits, and regulating private drainage.
If a property has roof gutters, downpipes, subsoil drains and stormwater drainage that are not connected to our stormwater system, then we may request that it is connected to our stormwater drainage system, if available and practical to do so.
To report an issue with our stormwater infrastructure please get in touch.
Your role
It’s important that residents play a part in keeping our waterways healthy and functioning:
- You must ensure any stormwater within your property from hard areas, including roofs and driveways, is collected and drained appropriately.
- You must maintain any private stormwater system on your property, including downpipes, gutters, private stormwater pipes, and gully pits, in a good operational condition.
- You are not permitted to construct a barrier (dam, levy etc.) that interferes with the natural path of stormwater.
- You are not permitted to divert or change the natural flow of stormwater.
- You are required to control stormwater associated with any construction work which takes place on your property.
- You must keep the natural watercourses and overland flow paths free of debris regardless if there is a drainage easement on your property, and free of obstructions to allow runoff passing through your property in a safe manner and to minimise any potential damage.
Discharging stormwater
Stormwater collected from a property can be discharged by the following points of discharge, subject to our approval. Generally, there is only one discharge point for each lot:
- to a kerb and gutter discharge point
- where the lot falls away from the street and there is a stormwater pipe or similar provided with an approved connection point to a public network, then the property must discharge to that drainage network
- if the above aren’t possible, you can look at disposal onsite (soakage trench) or pressured flow via a pump station. However, these approaches require our approval.
Please note: it is illegal to direct or discharge stormwater onto a neighbouring property.