Riverine flooding information for North Esk, South Esk and kanamaluka/ Tamar Rivers

Version 1 July 2024

Map 1 – Levee Protected are of Invermay to a 1% Annual Exceedance Probability (AEP) flood event (Major Flood).
*AEP is a term used to the express the percentage of likelihood of a flood, of a given size or larger, occurring in a given year.

Map 2 – Levee Protected are of Invermay if a failure of the levee occurred at 1% AEP. A flood greater than 1% AEP will overtop the existing levee system and increase the flood extent.
*AEP is a term used to the express the percentage of likelihood of a flood, of a given size or larger, occurring in a given year.

Introduction

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 the Invermay and the Inveresk areas and provide you information on what you can do to prepare for, respond and recover from a major flood.

The maps at the start of this document are there to provide an understanding of the impact of a major flood in the Invermay and Inveresk area should the flood levee’s fail or overtop.

Overview

Invermay and Inveresk are one of the most flood prone areas in Tasmania, being on a floodplain at the junction of 3 major rivers:

• the South Esk River
• the North Esk River and
• the kanamaluka / Tamar River estuary.

Major flooding of the South Esk River is the greatest risk to Invermay, with a combined South Esk and North Esk Rivers flood event increasing the risk to the area.

Levees help protect properties around Invermay. However, there is no guarantee they can withstand a major flood.

Experiences in other countries show that levee failures can be gradual or sudden. Low lying parts of Invermay may flood quickly. Flood waters may isolate other areas of the suburb.

If the levees failed, people’s lives could be at risk in Invermay as evacuation would be difficult. Roads in and around the suburb will be closed due to the levee. Some other routes around Launceston may also be flooded. There will be long traffic delays. Isolated areas would probably not have services such as power, water and sewerage.  These may take some time to restore after a major flood.

The State Emergency Service, Tasmania Police and the City of Launceston have worked to identify Critical Decision Points (‘Trigger Points’) for actions that will keep people safe in a major flood event. These are outlined further in this document.

If the South Esk River is predicted to reach a certain flood height, a Voluntary Evacuation may be declared, it is recommended that you go somewhere safer until the water goes back down. If the river reaches a higher level, a directed Mandatory Evacuation will commence.

If a Mandatory Evacuation is called, services such as electricity, water and gas will be cut off to reduce hazards and protect assets so services can be restored as soon as possible when flood waters go down. If you decide to stay you will not have any of these services in your house – it is much better if you leave and leave early. If you stay, you could put yourselves and others at risk.

If you have pets, you should take your animals with you if you can.

If you can, it is best to stay with family or friends in a safer place while your home is at risk of flooding.  If you have nowhere to go, there is likely to be an evacuation centre opened at the Silverdome – 55 Oakden Road, Prospect Vale. Keep checking Tas ALERT or listen to ABC local radio during a flood event for important information.

SES, City of Launceston and Tasmania Police can also provide information on where to go and how you can get there.

In such flooding events, some areas outside of Invermay may also be isolated due to flooding of the low lying areas, roads may have flood waters across them. It is dangerous to drive through flooded roads, particularly in isolated areas. It is recommended to find an alternative route.

Traffic is likely to be heavy throughout the city as roads and levee gate closures restrict traffic movements, so the best option is to leave early and allow plenty of time to get to a safe place.

If the levees fail or are overtopped, people who did not evacuate early when directed

• put their lives and the lives of others at risk due to the likely rapid flooding of some buildings and roads, the flooding of evacuation routes, and the isolation of other areas from help
• cannot expect to have access to emergency services such as ambulance, police, fire, or SES
• cannot expect to have services such as electricity, gas, water, sewerage or telecommunications
• may be exposed to waste water as the sewerage system will be overwhelmed with water and not function.

Check TasALERT.com for key information during a flood event.

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

If you live in a low-lying area you may be at risk of flooding if the levee system fails. Consider leaving early during the Voluntary Evacuation stage. Even if your home is not flooded, access to the area will be restricted. There may not be utility services such as power, gas and water for some time.

Never drive through, or enter flood waters.

Knowing what to do can save your life and help protect your property. Preparing a Home Emergency Plan is one of the best ways to prepare.

Include the stages of evacuation and triggers for action in your Home Emergency Plan.

Map 3: Evacuation routes to the Silverdome Evacuation Centre from the Inveresk/ Invermay area.

• Green route – via Wellington Street noting that this route closes early with levee gate closures at Charles Street bridge.
• Yellow route – via Wellington Street, Westbury Road and to Oakden Road
• Red route – vis Wellington Street, Midland Highway (Southern Outlet), Bass Highway and to Oakden Road.

您有洪水風險嗎？

A 1% Annual Exceedance Probability (AEP) flood event has a 1% chance of occurring any given year. You can expect to see a flood of this frequency at least once in your life.

Launceston has a long history of flooding.  Since European settlement:

• 1852, 1863 and 1893 were serious flood events recorded for Launceston.
• 1929 was the most severe flooding recorded in modern history. Over a thousand homes and buildings were damaged, with some swept from their foundations. The two suspension bridges over the Gorge area were damaged. Four thousand people were evacuated from Invermay, Inveresk and Margaret Street areas. The 1929 floods provided incentive to build the levees. It was not until 1940 that Launceston recovered from the flood.
• 2016 – Launceston prepared for a major flood event and closed some levees. Previous upgrades of the levee system helped avoid losses of about $216 million, had the previous ageing levees failed.
• 2022 – Launceston narrowly escaped a major flooding event.

我應該做什麼？

Check the map to see whether your home or business is likely to be at risk during a flood or in a levee protected area. The risks to your home or business may be potential inundation, or the loss of utility services and isolation.

• Prepare an Emergency Plan for your home and business. Consider what you need to do in the event of an evacuation and what you will need to take with you. See 為緊急情況做好準備 – 為個人和家庭準備應急措施的指南。. 
• Assess your home or business and prepare it to minimise possible flood damage in the event of a levee failure.
• If you have extra needs due to disability, illness or lack of mobility, it is a good idea to think about what your specific needs might be in a flood event before a flood event happens.
• Think about family, friends and neighbours who live close by who may need help, consider including them in your personal plan

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

The BoM issues a Flood Watch when predicted weather might cause floods for the North Esk River. A Flood Watch may:

• be for a specific area such as the South Esk River catchment, or
• be generalised such as for Central North river basins

The BoM issue Flood Warnings with specific flood heights for the South Esk River and North Esk River. Flood gauges along the rivers provide warnings of flood heights and the possible impacts in Launceston. Tides can also add to the flooding risk around Invermay.

Critical Decision Points

The North Esk and South Esk rivers have pre-determined triggers for an evacuation to be declared. Tasmania Police and SES will issue the evacuation notice.

Evacuation triggers – Flood height and water volume flowing from the South Esk River at Trevallyn Pond

• Voluntary Evacuation – BoM Moderate Flood Warning – 130.16 mAHD or 1600 cumecs (m³/s)
• Mandatory Evacuation – BoM Major Flood Warning – 130.95 mAHD or 2250 cumecs (m³/s)

Keep up to date with warnings and other key information at tasalert.com or listen to ABC local radio. BOM warnings can be found on their website at Tasmania Weather and Warnings (bom.gov.au)

*What is a cumec of water? – One cumec equals one cubic meter of water flowing past a point in one second. One cubic meter of water equals one thousand litres and weighs one tonne.

• TasALERT.com
• 您當地的 ABC 電台 或
• 這 氣象局 網站.

了解警告和關鍵資訊

	建議 (黃色)： 已發生事件。目前沒有立即危險。請隨時更新最新情況，以防局勢變動。.
	觀察與行動（橘色）： 威脅等級升高。情勢正在改變，您現在就必須採取行動保護您和您的家人。
	緊急警告（紅色）： 緊急警報為最高級別的警報。您可能身處危險之中，需要立即採取行動。任何延誤都可能危及您的生命。.
	社群更新（藍色）： 針對特定事件或事故，向受影響社群提供的具體資訊和最新消息。.
	事件（白色）： 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 at Invermay/ Inveresk

While no two floods are the same, the following table shows what you can expect at different flood levels around the East Launceston and city levee protected areas. Even if your property is not flooded, you need to think about access routes.

Enact Emergency Plans – Moderate Flood Warning –South Esk River @ Trevallyn Pond – 129.90 mAHD / 1500 cumecs (m³/s)

• Potential inundation of some of the West Tamar Highway near the Paterson Bridge – this road will continue to be influenced by the tide heights.
• Changing traffic conditions
• Potential inundation of Henry Street – Road Closure
• Closure of levee gates commences.
• Arterial traffic routes are still open.

Voluntary Evacuation – Moderate Flood Warning – South Esk River @ Trevallyn Pond – 130.16 mAHD – 1600 cumecs (m³/s)

• You will be advised to evacuate, it is strongly recommended that you do so.
• If time allows, emergency services will start door knocking the low-lying areas of Invermay/Inveresk and provide evacuation information.
• Closure of most levee gates as water height increases, however Charles Street Bridge will remain open. Inundation of low sections of the West Tamar Highway commences
• Traffic flow remains possible into the city via Charles Street and Invermay Road / Tamar Street.
• Expect traffic delays.
• Water may be trapped behind levees due to the rainfall.

Mandatory Evacuation – Major Flood Warning – South Esk River @ Trevallyn Pond – 130.95 mAHD / 2250 cumecs (m³/s)

• You will have to leave your home if it is within the levee protected areas.
• Utility services such as power, gas and water are likely to be lost. There may be interruptions to sewage service
• Tasmania Police will direct evacuation and secure the evacuated area.
• Closure of all levee gates including the Charles Street Bridge.
• Many other roads throughout the city are closed due to flood waters.
• Traffic flow is restricted, only allowing traffic to leave Invermay via Invermay Road over Tamar Street Bridge.
• Expect long delays in traffic movements.
• Access into Invermay is restricted to Tasmania Police and Emergency Services.
• There is the possibility for flooding to exceed the height of the levees, if this happens flood waters will enter Invermay and Inveresk.

了解你的風險，做好準備，盡可能降低風險，與他人聯繫，保持警惕並安全行動。.

BEFORE

1.    Know your risk

Depending on your location, you may experience floods differently. However if you live in the flood prone areas of East Launceston and the city areas you may be impacted by flood waters and not have power, gas, water and sewerage services should there be a major flood and levees are breached or fail.

2.    Prepare your household

制定包含風暴和洪水應變計畫

思考一下在風暴或洪水來襲時你會怎麼做，意味著你準備得更充分，每個人都會更安全。制定一個家庭中的每個人都理解的緊急計畫。有檢查表可以幫助你思考你的計畫——請參閱 為緊急情況做好準備 – 為個人和家庭準備應急措施的指南。. 

定期檢查您的計劃，並讓家中的每個人都設想一次可能影響您家的洪水情況來進行測試。.

Share this plan with friends and family, and any others which may need to know, i.e. childcare, support services etc. Ensure they are aware of the roles they will take if you enact your plan.

準備一個緊急救生包

定期測試收音機和手電筒的電池。.

3.    Reduce your risk from flooding where you can

• 在購買、維護或開發房地產時，請考慮風暴、洪水和其他災害。.
• 修剪或移除您家中、商家或您家附近有電力線的樹木和樹枝。.
• 保持您的排水溝和排水管暢通。.

4.    Connect with others

認識你的鄰居並參與你的社區。一個緊密的社區，在緊急情況下更安全、更有韌性，並有助於每個人在事後更好地恢復。檢查家人和鄰居是否安全，並了解正在發生的事情。.

DURING

5.    Stay alert

隨時留意周遭狀況。定期查看天氣預報、觀測數據和警報。.

• TasALERT.com
• 您當地的 ABC 電台 或
• 這 氣象局 網站.

6.    Act safe

• 監督兒童.
• 為可能的停電、停水或斷網做好準備。.
• 檢查您的緊急救助包是否已準備就緒。.
• 切勿靠近淹水區域，例如排水溝。. 永不 在洪水中有行走、玩耍、骑行或开车。你無法確定水下有什麼，或水有多深、流速有多快。20公分的湍急的洪水就很容易將人沖走並淹死。洪水可能很危險。.

您的房屋可能發生淹水時

• 將家居物品放在高處，以盡量減少潛在損壞。.
• 如果安全的話，請關閉水電和瓦斯。.
• 一種防止污水倒灌回屋內的好方法是將沙包放入塑膠袋中，然後用它們來堵塞馬桶、蓋住排水孔和水槽。.
• 趁你還能安全脫困時趕快離開。.

When you need to evacuate

• Mandatory Evacuation – You will be directed to leave the area by Tasmania Police.
• 請遵循 SES / 塔斯馬尼亞警方的建議。. 
• 帶上你的緊急求生包。.
• Go to friends or family in a safer place or an evacuation centre if you have no other option
• 讓別人知道你去了哪裡。.

照顧好你的動物

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.  For more information see RSPCA 應對緊急情況動物的指南 and RSPCA Tasmania Ready, Pet, Go!

Think about getting a PET PAL – a PET PAL is a friend or relative where you can take your pet(s) to during an emergency situation.  Talk to your PET PAL about your evacuation plans, further information can be found at the City of Launceston Emergency Management Hub

Avoid travelling during and after storms

• Do not go sightseeing. Sightseers delay emergency services, cause accidents and add additional vehicles to the traffic flow out of the Invermay area extending traffic movement delays.
• 注意危險，例如
  • 路面积水
  • 損壞的電力線
  • 山崩
  • 損壞的道路
  • 倒下的樹木或屋頂鐵片。.
• 切勿駕車通過淹水區域。洪水中的大多數死亡和救援事件都與駕車通過淹水區域有關。.
• Drive slowly and turn your headlights on when travelling on roads not affected by flood waters.

AFTER

• 請持續收聽 ABC 地方電台的最新消息、道路重新開放、社區會議等資訊。.
• 如果您離開家，請勿在聯邦緊急事務局 (SES) 或塔斯馬尼亞警方告知您安全之前回家。.
• 注意道路上的危險，例如路面上的泥沙或碎屑、道路/橋樑損壞以及正在進行清理和修復工作的工人。.

如果您的房屋已受損

• Be careful of fallen trees, broken glass, loose roofing or other hazards.
• 穿著堅固的靴子、手套和防護服。.
• 請使用手電筒，切勿在受洪水影響的建築物內使用火柴或蠟燭。.
• 將所有飲用水煮沸，直到被告知自來水再次安全為止。.
• Do not turn on electricity or gas until it is tested by a licensed electrician or gas fitter for safety.
• 如果您的房屋受損，需要暫時住在其他地方，請攜帶您的緊急應變包和寵物一同前往。
• 如安全，請拍攝任何損壞的照片，並聯繫您的保險公司。.
• 監督兒童.
• 檢查鄰居是否安好。.

如需更多資訊，請前往 www.ses.tas.gov.au 或 www.launceston.tas.gov.au/Emergency-Management-Hub.

保持獲取最新資訊及更多詳盡資料

Current warnings (TasALERT)            Tasalert.com

Bureau of Meteorology (BoM)           bom.gov.au/tas/warnings

Emergency Broadcasters                   ABC 91.7FM

TAS SES Social Media                       facebook.com/sestasmania

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

City of Launceston Council   6323 3000 City of Launceston Emergency Management Hub

National Relay Service (NRS)             relayservice.gov.au

Translating and Interpreting Services (TIS National)    www.tisnational.gov.au/

免責聲明

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.