Riverine and flash flooding information for communities around puthimiluna/ Great Oyster Bay on Tasmania’s East Coast

Draft version 0.2 May 2025 for community input – email ses@ses.tas.gov.au

To see the maps in more detail, see the Tasmanian Strategic Flood Maps.

Flooding from intense rainfall can cut the Tasman Highway in multiple places. This flooding could be

• deep
• impassable, and
• potentially dangerous. 

The Highway may also be cut in places to the north and south of this plan.  Inland alternative routes are

• also likely to be cut, and
• can be more isolated and dangerous.

Flood can isolate communities and properties along the coast for a short time. Waterways in the area are short, so flooding is likely to be for hours rather than days after rain stops.

The maps in this guide show the level of flooding that has a 1% chance of happening any year. You are likely to experience flooding such as that shown in the maps in your lifetime. Tasmanians need to prepare for flood events that may not happen often as well as the minor flooding they may have experienced.

Even if your home is not flooded you should prepare for

• isolation
• potential power and telecommunications outages.

The Tasman Highway may be cut in multiple places during a major flood event, depending on where the rain falls and how heavy it is. Travel in the area is likely to be difficult or impossible until roads are clear.

Floodwaters will likely isolate many areas along the East coast for a few hours at the most.  If you are safe at home or elsewhere, it is usually best you stay where you are until the flooding subsides. If you need to evacuate, you should leave early, before flood waters rise. Flood waters are likely to disperse quickly, once rain stops.

Check TasALERT.com or listen to ABC local radio for warnings and advice.

• Bicheno area: ABC Northern Tasmania 89.7 FM or 91.7 FM
• Swansea area: ABC Radio Hobart106.1FM or 936 AM
• Triabunna area: ABC Radio Hobart 90.5FM or 936 AM

Note areas outside township areas may lack mobile internet access and local radio coverage

Are you at risk of flood?

East Coast Lows can often bring intense rain that sometimes leads to flooding in areas along Tasmania’s East Coast.  Significant local flooding events happened in 2016, 2011, 1974, 1969, 1923, 1922, 1914, 1911, 1876, 1972 and 1870

What should I do?

• Check the map to see whether your home or business could flood.
• Assess your home or business and prepare it to minimise possible flood damage.
• Check if you can safely get to your home, work, or school during a flood.
• Prepare a Home Emergency Plan. See Get Ready for Emergencies – A guide for individuals and households to prepare for emergencies . 
• If you may be isolated and you must have access to services, you may need to evacuate early.

Bureau of Meteorology Forecasts, Warnings, and Observations

The Bureau issues a Flood Warning, Severe Weather Warning and/or Thunderstorm Warning for heavy rainfall that may lead to flash flooding whenever heavy rain is expected in an area. The time between the warning andheavy rain occurring can vary from an hour to 24 hours or more.

Whenever rain that may lead to flooding along the Swan River or Meredith River is expected, the Bureau will issue a Flood Watch – a “heads up” early advice of forecast weather that may lead to flooding. There are no formal warning levels for waterways in the area as the river systems are too short.

Rainfall Observations at places such as

• Bicheno
• Friendly Beaches
• Swansea, and
• Lake Leake

can indicate possible flood risks. Given the very short warning times, it is best to act on the BoM warnings rather than wait for any flood alerts during rainfall.

The Mt Koonya Radar is useful to be aware in real-time where heavy rain is falling for the areas south of Swansea.  Radar Rainfall estimates can also fill in gaps in areas where there are no rainfall stations. The North East of Tasmania is not well covered by BoM radar.

Understand the warnings and key information

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

• TasALERT.com
• your local ABC radio station or
• the Bureau of Meteorology’s website.

For more information see www.ses.tas.gov.au/warnings/ .

Flood levels

While no two floods are the same, the following describes what you can expect at different flood levels around the area. Even if your property is not flooded, you need to think about access. Different levels of rainfall can cause flooding depending on its

• intensity
• duration
• how wet the ground is beforehand, and
• where the rain falls.

Minor flooding can impact low-lying agricultural land. Livestock and equipment near waterways should be moved. There may be low level flooding across some roads, particularly (from North to South):

• Rosendale Road access to Apsley Gorge, parts of the Campground/ picnic area
• Tasman Highway
  • South of the Lilla Villa Bridge
  • North of Lake Leake Road
  • South of Springvale Road
  • North of Meredith River
  • Near Sandy Creek, Mayfield Beach
  • Near Trehawke Creek (Buxton River area)
  • North of Lisdillon Rivulet
  • South of Little Swanport River
  • Near Ravensdale Rivulet
• Lake Leake Road near Whelans Bridge
• Coles Bay Road East of the Tasman Highway junction (Apsley River)
• Glen Gala Road, Cranbrook
• Grange Road, Cranbook
• Some properties around Llandaff may flood, along with nearby property on Coles Bay Road. There are several low-lying properties along the Tasman Highway that are flood prone.

Major flooding

Rainfall of about the following amounts will cause major flooding in the area.  This level of rainfall has a 2% chance of happening any given year (based on rainfall records at Swansea up to 2016).

• 35mm in 1 hour
• 45mm over 2 hours
• 54mm over 3 hours
• 77mm over 6 hours
• 113mm over 12 hours

Key transport routes most likely to flood include (from north to south):

• Tasman Highway, many places, but particularly
  • Between Bicheno and Apslawn
  • Extended areas around Cranbrook
  • Near the Cygnet River, south of Cranbrook
  • North of Lake Leake Rd
  • Around the Wye River, south of Crossins Road
  • North of Meredith River
  • Near the mouth of Saltwater Creek, Swansea
  • Near Stony River, south of Swansea
  • Around Buxton River
  • South of Little Swanport River and north of Ravensdale
  • North and south of Triabunna.
• Rosedale Road – access to Apsley Gorge
• Coles Bay Road
  • Near the junction with Tasman Highway
  • Around the Friendly Beaches Road junction
  • Near Swanwick
• Old Coach Road river crossings
• Glen Gala Road, Cranbrook, extended areas
• Lake Leake Rd near Whelans Bridge
• Crossins Road
• Grange Road several places
• Swan River Road access to Dolphin Sands
• Esplanade area, Swansea, and some areas around Maria Road
• Freestone Point Road near the intersection with Tasman Highway

Aside from key routes prone to flooding, properties and some campsites in the area that are prone to flooding.  Of most concern (from North to South):

• Apsley Gorge waterhole access and campground
• Landaff riverside properties and some nearby properties on Coles Bay Rd
• Low lying areas northern parts of Swanwick, which may also be impacted by coastal inundation
• Cranbrook properties near Glen Gala Rd, Grange Rd, Springs Road and Tasman Highway
• At Swansea, Saltwater Creek may flood
  • Maria St
  • several properties on River Street, and
  • the Esplanade area, especially at high tide.
• At Triabunna, the Esplanade area. This area is also prone to coastal inundation.

Storm water runoff (overland flow) can affect other properties after intense rainfall.

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 Get Ready for Emergencies – A guide for individuals and households to prepare for emergencies. 
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
• Money
• 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. 

• TasALERT 
• your local ABC radio station or
• the Bureau of Meteorology’s website.

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

• RSPCA’s guidance on preparing for animals in an emergency
• Huon Valley Council’s advice on preparing an emergency pet plan
• the Primary producer farm flood readiness toolkit.

Avoid travelling during storms 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 TasALERT.com

Bureau of Meteorology (BoM)

Emergency Broadcasters ABC 936AM

TASSES Social Media facebook.com/sestasmania

Preparing for Flood Emergencies ses.tas.gov.au/plan-prepare/flood 

Glamorgan Spring Bay Council                gsbc.tas.gov.au                                 03 6256 4777

National Relay Service (NRS) relayservice.gov.au

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.