Riverine and flash flooding information for the Prosser River and surrounding minor waterways

Version 1.1 July 2025 Revised draft for community input – email ses@ses.tas.gov.au

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

Tasmanians need to prepare for flood events that may not happen often as well as the minor flooding they may have experienced.

When there is heavy intense rain the Prosser River and surrounding waterways can flood

• properties and roadways in and around Orford township
• some properties in areas outside Orford township
• the Tasman Highway and other roads
  • Between Orford and Buckland
  • North of Orford
  • West of Buckland
  • To the South of Orford.

Flood can isolate communities and properties along the coast for a short time, depending on where the rain falls and how heavy it is. All routes in and out of Orford, Buckland and surrounding areas may be cut in a major flooding event.  Flood waters, landslips or fallen trees can also cut backroads, making it dangerous to drive in isolated areas.

Waterways in the area are short, so flooding is likely to be for hours rather than days after rain stops. If you are safe at home or elsewhere, it is usually best to stay where you are until the flooding subsides. If you need to evacuate, you should leave early, before flood waters rise. If you need to evacuate, pick up children from school or travel for some other reason, you should do so early, before flood waters rise.

Flooding around Orford is more likely at high tide. The area is prone to coastal inundation.

The maps in this guide show the level of flooding that has a 1% chance of happening any year due to riverine flooding from

• the Prosser River and nearby minor waterways
• Stormwater run-off (overland flow) from heavy local rain, and
• coastal inundation.

You are likely to experience flooding such as that shown in the maps in your lifetime.

Even if your home is not flooded you should prepare for

• isolation
• potential power and telecommunications outages.

Check TasALERT.com or listen to ABC local radio for warnings and advice –
Triabunna area: ABC Radio Hobart 90.5FM or 936 AM

Note areas outside townships may lack mobile internet and local radio coverage.

Are you at risk of flood?

Past flooding events around Orford and the Prosser River include:

• June 2016 when up to 220mm fell over 72 hours
• June 2009 when extensive East Coast flooding caused a landslide at Paradise Gorge, and other routes in and out of Orford were cut
• August 1970 when up to 120mm fell in 24 hours
• May 1969 when up to 180mm fell in 48 hours.

What should I do?

• Check the maps to see whether your home or business could flood.
• Check 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.

Floods like the one shown in the maps or worse will occur again. No two floods are the same. If you live in a low-lying area, 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 flood waters. Roads and bridges may be washed out or unsafe.

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.

Bureau of Meteorology (BoM) Forecasts, Warnings, and Observations

BoM issues a 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 sometimes more.

BoM may issue a Flood Watch for southern rivers when predicted weather might cause floods over the next couple of days. The Flood Watch may include generalised areas when there is a risk of significant rainfall. 

TasWater operate gauges on the Prosser dams which measure river flow, however, these are too close to the township to provide useful warning information. 

Rainfall Monitoring and Observations

The Mt Koonya Radar is useful for real-time situational awareness of where heavy rainfall is falling.  Radar Rainfall estimates help to fill in gaps where there are no rainfall stations.

Rainfall stations at Orford, Triabunna, Buckland, Grindstone north of Triabunna and Nugent may provide useful observations, but rainfall can vary across the area. Tasmania’s East Coast is prone to flash flooding from intense rain so there may be little warning.

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.

Orford

Note flooding in places along the Tasman Highway may isolated the Orford area, even in locally more minor events.

In minor flood events

• Riverine flood water and storm water run-off may reach some building floor levels and impact low-lying paths, parks and backyards.
• Livestock in potential flood areas should be moved to higher ground.

Moderate flooding in and around Orford

• May mean water starts to enter some homes and other buildings
• There is a risk the Tasman Highway near the golf course is inundated.

A major flood event around Orford

• May be for example due to heavy rainfall in the river catchment of about
  • 51mm in 3 hours
  • 74mm in 6 hours
  • 110mm in 12 hours.
  • 197mm in 48 hours
• Is likely to inundate all access routes to/ from Orford, isolating the town
• Isolate parts of the town divided by river crossings
• Inundate low-lying areas of the town around
  • The Esplanade, Gore Street, Cross Street and nearby Walpole Street, plus some parts of Murphy Court
  • Riverside Drive and surrounds
  • the end of Walters Drive and Rudolf Ave
• Cause storm water run-off that may flood other areas of the town, for example.

Buckland and inland areas along the Prosser River and its tributaries

Buckland township is not at risk from riverine flooding, but in the major event:

• Stormwater run-off (overland flow) can affect some properties if there is very heavy intense rain
• The northern and southern sides of the township, and properties to the north along Buckland Road may become isolated for a short time.
• Floodwaters are likely to cut the Tasman Highway to the east and potentially the West of the township.
• Floodwater may impact Stonehurst Road and at least one property.

Areas to the south of Orford

Stormwater run-off (also known as overland flow) may impact parts of

• Shelley Beach
• Spring Beach
• Rheban Road, Wielangta Road and minor roads in the area.

This stormwater runoff is likely to be fast flowing but generally shallow and likely to last only a short time once rain has stopped.

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

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. Familiarise yourself with evacuation routes or higher places that will be safer from flooding.

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 that everyone in the household understands what would need to happen in a flood.

Prepare an Emergency Kit

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. 

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

Understand the warnings and key information

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 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) bom.gov.au/tas/warnings

Emergency Broadcasters ABC 936AM

TAS SES Social Media facebook.com/sestasmania

SES – Preparing for Flood Emergencies

Glamorgan Spring Bay Council phone 03 6256 4777

National Relay Service (NRS)

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.