Moonah – Derwent Park flood guide

Flooding information for areas between Barossa Creek and New Town Rivulet, including Moonah, Derwent Park, Lutana and West Moonah.

Moonah Derwent Park flood mapping showing 1pc AEP inundation

During a major flood event in Hobart and Glenorchy, flooding from minor waterways and heavy rain may inundate parts of Moonah and Derwent Park. Only small areas of Lutana and West Moonah are likely to be inundated. Moonah and surrounding areas are likely to be isolated for some hours as waterways to the north and south flood major routes.

It is important you understand what a flood can look like in your area so you can be prepared. You are likely to have a flood that causes significant damage in the area at least once in your lifetime.

Glenorchy and Hobart areas are prone to flash flooding, depending on how rain falls across Kunanyi/ Mount Wellington. This means there can be little warning before waterways flood. There can also be stormwater run-off in other places if there is heavy rain. This can be difficult to predict.

Flooding may isolate some areas for up to 6 hours but more likely for just a few hours. You should prepare for short-term isolation plus power or telecommunications outages.

Some key roads may be flooded. Traffic is likely to be congested. Travel may be difficult or impossible. If you are safe at home or wherever you are at the time, it is usually best you stay there until the flooding goes down. If you need to leave during a flood, make sure your route safe. 

Go to tasalert.com.au or listen to ABC local radio 936AM for warnings and advice.

Are you at risk of flood?

Example past local flood events include:

  • May 2018 – The Southern Tasmanian Extreme Weather Event caused flooding around Hobart. There was 236mm of rain on Kunanyi/ Mount Wellington. 
  • April 1960 – About 200mm of rain over 3 days and caused damage across Hobart.
  • June 1947 – Two separate flooding events impacted the Glenorchy area.

What should I do to be prepared?

  • Check the map to see whether your home or business is at risk of being flooded. If it is, you should have a plan for leaving during a flood event. During a flood event, go to TasALERT or listen to ABC local radio to find out about evacuation centres or other places to shelter. 
  • Check if you can safely get to your home, work, or school during a flood. If you need to leave during a flood, make sure your route is safe or leave early before floodwaters rise.
  • Prepare your home or business to minimise possible flood damage.
  • Prepare a Home Emergency Plan.
  • If you have a business in the area, you should have a plan that covers flooding.  Business Tasmania can help– see www.business.tas.gov.au/manage_a_business/ .

Floods like the one shown in the map or worse will occur again. No two floods are the same.

If you live in a low-lying area or near a watercourse, your house may flood. Even if your home is safe, you may need to detour around flooded areas or your road access may be cut. Never drive into or enter flood waters. Roads and bridges may be washed out or unsafe. Avoid travel during floods.

Knowing what to do can save your life and help protect your property. Having a Home Emergency Plan is one of the best ways to prepare. Decide on weather and rainfall triggers for when to act.

To see map information in more detail, go to the Hobart City Council’s website.

Bureau of Meteorology Forecasts, Warnings, and Observations

Whenever heavy rain is expected in an area, the Bureau issues

  • a Flood Watch
  • Severe Weather Warning and/or
  • Thunderstorm Warning for heavy rainfall that may lead to flash flooding.

The time between the warning and heavy rain falling can vary from an hour to 24 hours or more. It is best to act on the warnings from the Bureau of Meteorology rather than wait for local flooding alerts.

Tracking Rainfall on Kunanyi/ Mount Wellington can help predict flooding around Glenorchy and Hobart.

The Mt Koonya Radar is useful to see when and where heavy rainfall is falling. 

Understand the warnings and key information

Keep aware of what is happening around you. Check forecasts, observations and warnings regularly.

 Advice (Yellow): an incident has started. There is no immediate danger. Stay up to date in case the situation changes. 
Watch and Act (Orange): There is a heightened level of threat. Conditions are changing and you need to start taking action now to protect you and your family
Emergency Warning (Red): An Emergency Warning is the highest level of warning. You may be in danger and need to take action immediately. Any delay now puts your life at risk. 
Community update (Blue): Specific information and updates for affected communities regarding a particular event or incident.
Incident (White): an incident is the initial occurrence of an event before it becomes an emergency warning. As soon as an incident is reported, TasALERT published basic information including the type and location of incident.

Flood levels around Moonah/ Derwent Park

While no two floods are the same, the following table shows what may happen if there is flooding around Moonah and surrounding areas. Even if your property is not flooded, you need to think about access.  The rainfall amounts below that might cause such an event are examples: other levels of rainfall can cause flooding depending on

  • how heavy it is
  • how long the rain lasts
  • how wet the ground is beforehand
  • how full dams are, and
  • where the rain falls.

A Minor Flood (less than 5% chance of happening in a year (Annual Exceedance Probability – AEP)

For example, up to about 68mm over 6 hours on Kunanyi/ Mount Wellington and/or about 50mm around Glenorchy.

May flood

  • some low-lying areas and parklands,
  • some sections of the of the intercity cycleway and
  • foreshore areas at high tide.

A Moderate Flood (above a 5% and below a 1% chance of happening in a year)

For example, between 69-86mm in 6 hours on Kunanyi/ Mount Wellington or between about 50-65mm at Glenorchy.

May flood areas of Brooker Highway, Main Road near Springfield Road and some other low-lying roads.

May impact some low-lying properties to above floor height.
There is likely to be flooding to the north and south around Glenorchy and Hobart, leading to very congested traffic.

A Major Flood (a 1% chance or less of happening in a year in the current climate)

For example, more than about 87mm in 6 hours or more on Kunanyi/ Mount Wellington and/or more than 65mm around Glenorchy.

Many areas of Main Road, Albert Road, Hopkins St, Charles St, Springfield Avenue, Derwent Park Road, Brooker Highway and surrounding areas at risk of flooding – see maps for details.

Many properties at risk of flooding to floor height or above – homes and businesses.

Unless there is an emergency or you are not safe where you are, you should shelter where you are during a flooding event.  Floods around Hobart rarely last more than a few hours. Traffic is likely to be very congested. Listen to ABC local radio or go to TasALERT for advice.

Overview of flood prone areas from New Town Rivulet to the Bridgewater Bridge

Know your risk, get ready, reduce risk where you can, connect with others, stay alert and act safe.

Before a flood

1. Know your risk

Flooding often happens in Tasmania and can cause widespread and significant damage. In the past 200 years there have been 78 flood related deaths in Tasmania. This guide is to help you understand flood risk in your area.

2. Prepare your household

Have an emergency plan that covers storms and floods

Thinking about what you would do in a storm or flood means you are more prepared and everyone is safer. Have an emergency plan that everyone in your household understands. There are checklists to help you think through your plan – see the SES website or Red Cross Rediplan.

Check your plan regularly and test it by everyone in the household thinking through a flooding scenario that may affect your household.

Prepare an Emergency Kit

Ready to Go

Battery powered radio and torch, spare batteries

Important information, such as your emergency plan

A list of emergency numbers

Food and water

First aid kit

Rubber or strong leather gloves

Pack when needed

Warm clothes, sturdy shoes or boots

Medicine, glasses or other essential items

Mobile phone and phone charger

Pet food and anything else they need

Photos and special keepsakes

Important documents, for example
– insurance papers
– passports and
– birth certificates

Regularly test batteries in radios and torches.

3. Reduce your risk from flooding where you can

  • Think about storms, flooding and other hazards when buying, maintaining or developing property.
  • Trim or remove trees and branches overhanging your home, business or near powerlines on your property.
  • Keep your gutters and drains clear.

4. Connect with others

Know your neighbours and get involved in your community.  A connected community is a safer and more resilient community in an emergency and can help everyone recover better afterwards. Check that family and neighbours are safe and aware of what’s happening.

During

5. Keep up to date

Keep aware of what is happening around you. Check forecasts, observations and warnings regularly. 

6. Act Safe

  • Supervise children.
  • Prepare for possible power, water or internet outages.
  • Check your emergency kit is ready to go.
  • Keep clear of flooded areas such as drains. NEVER walk, play, ride or drive in floodwater. You can’t always see what is under the water or how deep or fast-moving the water is. It is easy to be swept away and drown in as little as 20cm of fast-moving water. Flood water can be dangerous.

When your home may be flooded

  • Put household items up high to minimise possible damage.
  • Turn off the electricity and gas if it is safe to do so. 
  • A great way to stop sewerage flowing back into your home is to place sandbags inside plastic bags and use them to block toilets and cover drains and sinks.
  • Leave while you can get out safely.

If you need to evacuate

  • Follow the advice from SES / Tasmania Police.  
  • Take your emergency kit. 
  • Go to friends or family in a safer place or an evacuation centre. 
  • Let others know where you have gone.

Look after your animals

You are responsible for your animals in an emergency. If you have pets and other animals it will take you longer to evacuate in a flood or other emergency. Move livestock from flood prone areas well before flood waters may rise.  For more information see

Avoid travelling during and after storms

  • Do not go sightseeing. Sightseers delay emergency services and cause accidents.
  • Watch out for hazards such as
    • water over roads
    • damaged powerlines
    • landslides
    • damaged roads
    • falling trees or roofing iron.
  • Never drive through flood waters. Most deaths and rescues in floods are from people driving through flood waters.
  • Drive slowly and turn your headlights on roads not affected by flood waters.

After

  • Keep listening for ABC Local Radio updates, road re-openings, community meetings, etc.
  • If you left your home, do not return home until SES or Tasmania Police tell you it is safe to do so.
  • Be aware of road hazards, such as mud or debris on the road, damaged roads/bridges and crews working on clean-up and repairs.

If your home has been damaged

  • Stay at ground level while checking for damage. Be careful of fallen trees, broken glass, loose roofing or other hazards.
  • Wear strong boots, gloves and protective clothes. 
  • Use a torch, never use matches or candles inside flood affected buildings. 
  • Boil all drinking water until you are told the tap water is safe again.
  • Do not turn on it is tested by a licensed electrician or gas fitter for safety.
  • If your home is damaged and you need to stay somewhere else, take your emergency kit and pets with you
  • Take photos of any damage if safe for you to do so and contact your insurance company.
  • Supervise children.
  • Check neighbours are okay.

For further information go to www.ses.tas.gov.au

Staying informed and further information

Current warnings (TasAlerts) alerts.tas.gov.au

Bureau of Meteorology bom.gov.au/tas/warnings

Emergency Broadcasters ABC 936AM

TAS SES Social Media

  • facebook.com/sestasmania
  • twitter.com/sestasmania

SES – Preparing for Flood Emergencies

Glenorchy City Council                                            6216 6800

National Relay Service (NRS)

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Disclaimer

The maps show potential flooding risks from consistent levels of rainfall across catchments, such as a 1% Annual Exceedance Probability (AEP).  In flooding events, rainfall is likely to be more inconsistent across a catchment, so these flood maps should be considered indicative only.  The mapped areas of flood risk show higher probability of inundation. Other areas have lower probability of flooding, but in severe and rare events (rarer than 1%AEP), other lower areas may be also at risk of inundation.

The information in this guide is current at the date of publication. While every effort has been taken to ensure the validity and accuracy of the data presented, the State Emergency Service does not take responsibility for data error or omission. Please see the standard Tasmanian Government’s Copyright and Disclaimer Statement for more details.