Townsville Floodplain Management Strategy by Townsville City Council

Towards a Flood Resilient Townsville An Interim Floodplain Management Strategy The Townsville Floodplain Management Strategy is a joint initiative of Townsville City Council and the Queensland Government.

key project

outcomes The Townsville Floodplain Management Strategy is enabling Council to better understand and respond to flooding hazards across our city’s urban areas. Through detailed research and community consultation, council has analysed flooding hazards in terms of likely building impacts, community acceptance of risk, likely damage costs, the frequency of deep-fast flowing water and emergency management measures. This analysis provides a foundation for managing flooding in Townsville. It can help ensure that the risks of flooding are reduced through the best mix of urban planning, infrastructure and emergency response measures. Community engagement has been critical to the development of the Townsville Floodplain Management Strategy. It will continue to play a vital role in implementing the Strategy’s key actions, which are: >> Review land-use practices to ensure development master plans better consider all flood risks. >> Review evacuation requirements and the suitability of available roads for evacuation to guide disaster management arrangements and prioritised road upgrades.

townsville floodplain management

Flood Hazard Analysis | Summary Report

>> Increase community awareness around the individual’s role in flood resilience such as awareness of risks, disaster management, uses beneath high-set homes and business continuity. >> Ensure future infrastructure planning accounts for flooding to provide the appropriate level of reliability and service in flooding events. >> Review projects in council’s Capital Works Plan, including renewal works, to evaluate synergies with flood management objectives. >> Identify future Main Roads upgrade projects to evaluate synergies with flood management objectives. >> Establish partnerships with developers to evaluate synergies with broader community flood management objectives. >> Engage with the insurance industry to work towards reducing the flood damage component of premiums.

report

contents 1. Outlining the Townsville Floodplain Management Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. What is the nature of Townsvilleâ&#x20AC;&#x2122;s Floodplain? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. What are the Flood Hazards facing Townsville? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4. What Flood Emergency Issues should Townsville consider? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 5. What is the degree of risk posed by Townsvilleâ&#x20AC;&#x2122;s Flood Hazards? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 6. What are the costs of flooding? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 7. How can we respond to flooding? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 8. Key actions and next steps for the Townsville Floodplain Management Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Project Outline 2009–2012

Ground Level Survey >> Includes ground levels and underwater levels of watercourses >> Data to form basis of flood modelling

2010–2014

Flood Modelling Studies >> Computer modelling of various flood scenarios across the city >> Results in flood maps showing flood affected areas

2014–2015

Floor Level Survey >> Use of Terrestrial LiDAR to capture floor level data.

early 2015

Community Input Survey >> Broad community input to guide the Floodplain Management Strategy >> Gain an understanding of the community’s preference of different types of floodplain management measures >> Understand the community’s expectations of flooding risks

late 2015

Flood Hazard Analysis Analysis of flood modelling to identify flood hazard areas based on >> What are the flood hazards facing Townsville? >> What Flood Emergency issues should >> What is the degree of risk posed by Townsville consider? Townsville’s Flood Hazards? >> What are the costs of Flooding?

2016–2017

Floodplain Management Strategy Options Development >> Development of strategic initiatives with broad floodplain benefits >> Education about how we move towards a flood resilient Townsville

mid 2016–early 2018

Options Analysis

>> Review and refine options based on community engagement and flood hazard analysis results

2. what is the nature of

townsvilleâ&#x20AC;&#x2122;s floodplain? The Townsville Floodplain Management Strategy focusses on the combined floodplains of the Ross, Bohle and Black Rivers, and also encompasses the neighbouring floodplains of Althaus and Bluewater Creeks to the north and Alligator Creek to the south. The entirety of this Townsville Floodplain area is illustrated in the map overleaf. First settled over 150 years ago, the historical development of Townsvilleâ&#x20AC;&#x2122;s Floodplain is important to our understanding of its flood risks: >> The Townsville floodplain was first settled around the port at the mouths of Ross Creek and the Ross River. >> Settlement progressed southwest from the mouth of Ross Creek and remained bound by the Ross River to the south. >> Ross River has Blacks, Gleesons and Aplins weirs which were originally developed for water supply. >> Two developments in the 1970s made significant changes to the floodplain - the creation of Bicentennial Park, permanently separating Ross Creek from Ross River; and the creation of Ross River Dam which provided significant downstream flood mitigation through retention of flood flows. >> Prior to these changes, overflows from the Ross River could flow into the Bohle River for moderate to large floods. >> The changes in the 1970s led to growth westwards towards the Bohle River and south of the Ross River. >> The lower Ross River and Ross Creek floodplains today contain large residential areas and the majority of commercial use areas, with only a small fraction of the land use being industrial. >> Development in the Bohle River floodplain includes the suburbs of Kirwan, Thuringowa Central, Condon, Rasmussen, Kelso, Bohle Plains, Burdell, Cosgrove, Shaw and Bohle. >> The majority of settlement has been to the eastern side of the Bohle River with the west being mostly

rural. Current development sees areas of residential development opening up to the west of the Bohle River. >> Louisa Creek, a major tributary of the Bohle River, contains the suburbs of Heatley, Mount Louisa, Garbutt and Mount St John. Other tributaries include Stony Creek, Saunders Creek and Little Bohle Creek. >> There are large amounts of industrial land use in the Bohle and Louisa Creek floodplain particularly in Garbutt, Mount St John, Bohle and Shaw. >> The Black River floodplain is to the west of the Bohle River. It is mostly rural and contains the Yabulu Nickel Refinery. >> Low density rural residential areas exist in the suburbs of Jensen, Black River, Yabulu and Bluewater. Traditional style residential areas exist in Mount Low and Bushland Beach. >> The Alligator Creek floodplain includes areas of rural residential development. >> Inundation in Townsville can result from 3 different mechanisms that have the potential to occur together: storm tide (cyclones), flooding in larger waterways from long rainfall periods (Ross River) and localized rainfall within the urban areas (flash flooding). These 3 mechanisms can have vastly different management requirements. >> Climate change has the potential to increase the severity of flooding. Any management measure must be mindful of the potential change in flooding severity over time. >> Building in under high-set homes in older areas is the primary reason for a number of households being affected by flooding.

450000

Leichhardt Creek

460000

470000

Sleeper Log Creek

ck Ali

k ee Cr

ek Cre

ek re C r

Low

e at w ue

Halifax Bay

HI G HW AY

reek Healy C

7880000

BR UC E

Stony Creek k Cree

Althaus Creek BRUCE HIG HW AY

Lo Cr

ive r

Bluewater Creek

WOO

LCO CK STREET

ive r

Alic eR

r Rive hle Bo Bohle t le Lit River

Bohle River

SHAW

Bla c

7870000

ek Cre s u ha Alt

Bla We

IN G ROAD

R Ross

7860000

iver

Black River

Palm Tree Creek

Cen tra

ek re lC

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townsville floodplain management

Flood Hazard Analysis | Summary Report

tral Cen

k Cree

Ross Ri ver

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Ross Dam

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7 490000

Horseshoe Bay Alma Creek Arcadia Nelly Bay Gustav Creek

500000

Townsville Floodplain CORAL SEA

Picnic Bay

0 0.5 1

7880000

480000

Retreat Creek

Kilometres

LEGEND

Weirs and Dams Freeway Highway

Three Mile Creek

Main Road Secondary Road

Cleveland Bay

Trafficable Road Major Catchments Suburbs North Ward

Captains Creek

Goo

Cr e

Ro s

ek Louisa Cre

eek Cr

ndi C

ree k

Aplin's Weir

Stuart Creek

Ross Creek

Cocoa Creek

Gordon Creek

df San

Gordon Creek

ly C

ack eir Gleeson's Weir

E ND FL I

Cre ek All

Crocodile Creek BRUCE

HIG

H WA Y

HI GH

k ee Cr s in Pla

AY W

Creek

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l til An

480000

Crocodile Creek

iga

k ee Cr hs

Stuart Creek

Upper Ross River

Lake Ross

Whit es Creek

tor

k ree Stua rt C

Alligator Creek

IG HW AY

ek re

c Sa

kC Dic

BR UC EH

7860000

FLIN

DER S

ek Cre

GH W AY

Sandfly Creek

ile od

Gordon Creek

c Cro

k re e

BRUCE H I

AY HW G

Lower Ross River

Waterway or waterbody Urban Areas 7870000

ouisa reek

490000

500000

450000

460000

470000

TOOLAKEA BLUEWATER

7880000

BR UC E

HI G

Halifax Bay SAUNDERS BEACH

HW AY

BLUEWATER PARK

YABULU

See Inset A

BEACH HOLM

BUSHLAND BEACH

CO MOUNT LOW

LYNAM

BOHLE BURDELL

BLUE HILLS

DEERAGUN

SHAW

SHA

BLACK RIVER

7870000

MO ST

JENSEN

AD W RO

See Inset C

3. what are the flood hazards RANGEWOOD

MOU LOUI

KIRWA THURINGOWA CENTRAL

BOHLE PLAINS

facing townsville?

7860000

The Townsville Floodplain Management Strategy reveals that the degree of flooding hazard is dependent on: >> the frequency of flooding HERVEY >> the depth of

ALICE RIVER

CONDON

See Inset D GUMLOW

RANGE floodwaters

>> the velocity of floodwaters >> the warning time available ahead of flooding, and >> the rate of rise of floodwaters. The degree of hazard on certain areas of the floodplain determines the potential danger of building in these areas. These maps illustrate the flood hazard for events occurring up to a probability of 1 in 100 in any given year â&#x20AC;&#x201C; known as the 1% annual exceedance probability (AEP) flood. This is the standard that is presently used for land-use planning in Townsville. New development in Townsville must also address theGRANITE risks of a 1% AEP flood. VALE The hazard criteria are based on the depth and velocity of floodwaters and are used to guide safety considerations within floodplains.

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townsville floodplain management

Flood Hazard Analysis | Summary Report

KELSO

PINNACLES

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9 480000

490000

FLOOD HAZARD 1% ANNUAL EXCEEDANCE CORAL PROBABILITY SEA

CORAL SEA

0 0.5 1

Kilometres

LEGEND 7880000

1% AEP Flood Hazard

H1 H2

SHELLY BEACH

H3 H4 H5

PALLARENDA H1 H2 H3 H4 -

TOWN OMMON

Generally safe for people, vehicles and buildings Unsafe for small vehicles Unsafe for vehicles, children and the elderly Unsafe for people and vehicles

H5 - Unsafe for people or vehicles. Buildings require special engineering design and construction Cleveland H6 - Unsafe for people or vehicles. All building types Bay considered vulnerable to failure.

Freeway Highway Main Road

See Inset B

Suburbs

ROWES BAY NORTH WARD SOUTH TOWNSVILLE

WEST END

RON MCLEAN D R IV E

HERMIT PARK

UNT ISA

ANNANDALE

IDALIA

7870000

GARBUTT

CLUDEN

D OA THE RIN G R

CAPE CLEVELAND

STUART

DOUGLAS

HW AY

WULGURU FLIN DE R

MURRAY

ROSENEATH

7860000

OUNT JOHN

BR UC EH IG HW AY

MOUNT STUART

NOME

JULAGO

OAK VALLEY

ALLIGATOR CREEK BROOKHILL

ROSS RIVER

MOUNT ELLIOT

480000

490000

INSET A 0

0.5

Kilometers

Halifax Bay

YABULU BUSHLAND BEACH BEACH HOLM TOWN COMMON

BLACK RIVER

BRU CE H

IGH

MOUNT LOW WA Y

BOHLE

JENSEN

BURDELL DEERAGUN

BOHLE PLAINS INSET C 0

0.5

BOHLE

W OO L COCK STREET

SHAW

MOUNT ST JOHN

WEST END

SH A

Kilometers

D OA WR

COSGROVE

GARBUTT MOUNT LOUISA

CURRAJONG

VINCENT

SHAW

GULLIVER HEATLEY

AITKENVALE KIRWAN BOHLE PLAINS

CRANBROOK

ANNANDALE

THE RING ROAD

DOUGLAS GUMLOW

townsville floodplain management

MURRAY

CONDON MOUNT STUART

Flood Hazard Analysis | Summary Report

PALLARENDA INSET B 0

0.5

Kilometers

TOWNSVILLE CITY

Cleveland Bay

SOUTH TOWNSVILLE

RON MCL

N EA

NORTH WARD

BELGIAN GARDENS

E IV

ROWES BAY

TOWN COMMON

Cleveland Bay

STUART

CASTLE HILL

RAILWAY ESTATE

WEST END HYDE PARK

HERMIT PARK

OONOONBA

CLUDEN

GARBUTT CURRAJONG ROSSLEA

PIMLICO

MOUNT ST JOHN

IDALIA

GULLIVER MUNDINGBURRA VINCENT

ET RE ST

MOUNT LOUISA

K OC LC OO W

INSET D 0

0.5

Kilometers

HEATLEY

WULGURU

ANNANDALE AITKENVALE

MURRAY

FLOOD HAZARD 1% ANNUAL EXCEEDANCE PROBABILITY

CONDON MOUNT STUART

LEGEND 1% AEP Flood Hazard

RASMUSSEN

H2 H3 H4

GUMLOW

Freeway Highway Main Road Suburbs

H5 H6

KELSO

PINNACLES

H1 H2 H3 H4 H5 H6 -

Generally safe for people, vehicles and buildings Unsafe for small vehicles Unsafe for vehicles, children and the elderly Unsafe for people and vehicles Unsafe for people or vehicles. Buildings require special engineering design and construction Unsafe for people or vehicles. All building types considered vulnerable to failure.

Plume and McIlwraith Streets, South Townsville, 1946

Corner of Hanran and Stanley Streets during 1946 flooding.

4. what flood emergency issues should

townsville consider?

The analysis of Townsville’s Flood Hazards informs emergency management measures and how they can best ensure public safety in rare and extreme weather events. In particular, it reveals the areas of potential isolation on the Townsville Floodplain during major flooding. It also reveals the risks to major evacuation routes. Isolation and evacuation issues, both of which are important to emergency management, are highlighted on the maps overleaf. Information displayed is as follows: >> 1% Annual Exceedance Probability (AEP) flood extent – the flood used as the basis for land-use planning; >> Probable Maximum Flood (PMF) – the theoretical maximum extent of flooding that could occur on the floodplain. This event has an extremely rare likelihood (in the range of 1 in 1,000,000 chance in any given year); >> Low Flood Islands – areas of the floodplain that are dry in the 1% AEP flood but surrounded by flood water and potentially inundated by larger floods (up to the PMF); >> High Flood Islands – areas of the floodplain that are dry in the PMF but surrounded by flood waters; >> Future Development – Areas of future development are required to address the risk from the 1% AEP flood; >> Major Road Closure Points – points on the major evacuation routes that are potentially closed due to flooding. The colours provide an indication of chance of road closure due to flooding in any given year.

Evacuations require significant lead times to ensure adequate warning and movement of residents. In Townsville, this is only possible for cyclone (storm tide) events and Ross River flood events, given the warning times required. Insufficient certainty of rainfall predictions in a timely manner means evacuations for localised rainfall events (flash flooding) are impractical. Residents in low-lying areas need to be aware of the flooding risks and make preparations ahead of the wet season for localised rainfall events. The mapping shows several of the existing major evacuation routes are subject to degrees of flooding with the potential to disrupt evacuation. The major evacuation routes will be reviewed to identify suitable alternatives and/or prioritised upgrades.

450000

460000

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! ( TOOLAKEA BLUEWATER

Halifax Bay SAUNDERS BEACH

7880000

! (

BLUEWATER PARK

See Inset A

YABULU

BEACH HOLM

BUSHLAND BEACH

! (

C MOUNT LOW

LYNAM BOHLE BLUE HILLS

DEERAGUN

BURDELL! (

M ST

JENSEN

BLACK RIVER

7870000

! (

! ( SHAW See Inset C ! ( COSGROVE

BOHLE PLAINS

RANGEWOOD

! (

MOU LOU

KIRWAN

! (

! ( CONDON

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ALICE RIVER HERVEY RANGE

See Inset D GUMLOW

! ( KELSO

PINNACLES GRANITE VALE

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townsville floodplain management

Flood Hazard Analysis | Summary Report

470000

15 480000

490000

HORSESHOE BAY

FLORENCE BAY

ISOLATION AND EVACUATION CORAL ISSUES

WEST POINT

SEA

ARCADIA 0 0.5 1

! (

NELLY BAY ! (

Annual Probabilty of Closure

! (

! ( ! ( ! ( ! ( ! ( ! ( ! ( ! ( ! (

PALLARENDA

Cleveland Bay

TOWN COMMON

See Inset B

! (

UNT UISA

1% to 2% 2% to 5% 5% to 10% 10% to 20% 20% to 50% > 50% Major Evacuation Routes

! (

Low Flood Islands

WEST END

! ( ! (

! ! ( ( ! (

! (

High Flood Islands 1% AEP Flood Probable Maximum Flood

SOUTH TOWNSVILLE

7870000

! (

0.2% to 1%

Main Road Suburbs Future Development

NORTH WARD

! ( ! (

! (

Never Closed PMF to 0.2%

Freeway Highway

ROWES BAY GARBUTT

Major Road Closure Points

SHELLY BEACH

MOUNT T JOHN

LEGEND

! ( PICNIC BAY

Kilometres

7880000

CORAL SEA

RAILWAY ! ( ESTATE

! (

! ( ! (

! (

! ( ! (

ANNANDALE

! ( IDALIA ! (

! (

CLUDEN

! (

DOUGLAS

CAPE CLEVELAND

STUART

WULGURU

! (

MURRAY

! ( ROSENEATH

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! (

NOME

MOUNT STUART

JULAGO

! (

OAK VALLEY

( ! (!

ALLIGATOR CREEK BROOKHILL

ROSS RIVER

MOUNT ELLIOT

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490000

INSET A 0

0.5

Kilometers

Halifax Bay

YABULU BUSHLAND BEACH BEACH HOLM TOWN COMMON

BLACK RIVER

MOUNT LOW

BOHLE

JENSEN

BURDELL

! (

DEERAGUN

BOHLE PLAINS

INSET C 0

0.5

Kilometers

! (

SHAW

! (

BOHLE

! (

COSGROVE

! (

GARBUTT MOUNT LOUISA

! ( CURRAJONG

! (

SHAW

VINCENT GULLIVER

HEATLEY

! ( ! ( ! ( AITKENVALE KIRWAN

! (

BOHLE PLAINS ANNANDALE

! ( CRANBROOK

! ( DOUGLAS GUMLOW

townsville floodplain management

MURRAY

CONDON MOUNT STUART

Flood Hazard Analysis | Summary Report

17 PALLARENDA INSET B 0

0.5

Kilometers

TOWNSVILLE CITY

Cleveland Bay NORTH WARD

SOUTH TOWNSVILLE

! (

BELGIAN GARDENS

Cleveland Bay

! (

ROWES BAY

TOWN COMMON

STUART

CASTLE HILL

RAILWAY ESTATE

! ( ! ( ! (

! (

! ( ! (

WEST END

! ( HYDE PARK

! ( ! (

! (

HERMIT PARK

! (

CLUDEN

OONOONBA

GARBUTT CURRAJONG

! ( ! ( MOUNT ST JOHN

! (

GULLIVER

! (

IDALIA

ROSSLEA

! (

! ( ! (

! (

MUNDINGBURRA VINCENT

! (

MOUNT LOUISA

INSET D 0

0.5

1 Kilometers

HEATLEY

WULGURU

ANNANDALE

! (

MURRAY

! (

AITKENVALE

! (

FLOOD HAZARD 1% ANNUAL EXCEEDANCE PROBABILITY

CONDON

! (

LEGEND Major Road Closure Points Annual Probabilty of Closure

! (

RASMUSSEN

! (

Never Closed PMF to 0.2%

! (

0.2% to 1%

! (

1% to 2% 2% to 5% 5% to 10% 10% to 20%

! (

GUMLOW

! (

! ( MOUNT STUART

! ( ! ( ! ( ! (

! (

KELSO

20% to 50% > 50% Major Evacuation Routes Freeway Highway Main Road Suburbs Future Development

PINNACLES

! (

5. what is the degree of risk posed by

townsville’s flood hazards? To gain an appreciation of the flood risks, the consequences of flooding in terms of impacted properties and infrastructure have been examined. Community input has provided guidance on the acceptability of flood risk. Broadly speaking, there are 3 main classifications of flood risk, which are defined as follows: Unacceptable risk: individuals and society will not accept this flood risk and measures must be undertaken to reduce risks to at least a tolerable level. Tolerable risk: a flood risk that can be lived with but if it can be cost-effectively reduced, should be; and Acceptable risk: a flood risk that can be lived with The graph below shows this Flood Risk Classification within the 7 major catchments. Results show that the Ross Creek and Bohle River catchments have the greatest amount of ‘unacceptable’ flood risk. The Bohle River catchment was also shown to have the greatest amount of ‘acceptable’ flood risk. Such ‘acceptable’ flood risk represents exposure to flooding hazard only in rare and extreme flood events. However, despite being unlikely, this acceptable flood risk still needs to be managed to ensure public safety, through emergency management.

flood risk by catchment 14,000

12,000

10,000

properties

8000

6000

4000

2000

0 ross river

ross creek

bohle river

alligator creek

black althaus bluewater

louisa creek unacceptable

captains creek / north ward tolerable

acceptable

flood free

6. what are the

costs of flooding? The Townsville Floodplain Management Strategy also provides estimates of the likely costs of flood event damage, by analysing the consequent risks to residential and commercial property, city infrastructure, and economic activity. Damages to residential and commercial properties were gauged firstly by assessing the potential for flood inundation - based upon the accurate measuring of existing property floor levels across the city. Next, industry research on the previous economic loss caused by inundation (including the related flood depth above floor levels) was applied to generate estimates of the likely damage costs to property that would be caused by flood events. The flood damage costs for infrastructure were estimated by calculating the replacement costs for those parts of the water, sewerage and road networks that could be damaged by flooding events.

The graph below shows the costs of average annual flood damages within Townsvilleâ&#x20AC;&#x2122;s 7 major catchments. The average annual figure is derived by calculating the relative frequency of flood events (from minor to extreme) and applying their respective damage costs. This overall cost is then averaged out on a year by year basis to produce an average annual figure. The results below show that the Ross Creek and Bohle River catchments are susceptible to the greatest flood damages. Across the floodplain, the total average annual flood damages are approximately $20 million.

average annual flood damages 8,000,000

7,000,000

6,000,000

5,000,000

4,000,000

3,000,000

2,000,000

1,000,000

0 ross river

ross creek

bohle river

alligator creek

black althaus bluewater

louisa creek residential

townsville floodplain management

Flood Hazard Analysis | Summary Report

captains creek / north ward

commercial

infrastructure

7. how can we

respond to flooding? The key objective of the Townsville Floodplain Management Strategy is to ensure identified flood risks are reduced by the carefully planned adoption of a range of potential response and mitigation measures. These measures are outlined below.

risk type

potential response

Existing risk to buildings and residents located in flood prone areas.

Development and building controls >> Flood proofing of buildings Structural Measures >> House raising >> Widening of flow channels and overbank areas to allow for improved flow conveyance >> Detention basins >> Permanent flood levees >> Upgrading of roads, bridges and other essential services Land use planning >> Buy-back flood affected properties

Potential future risk to development and residents that may be built on flood prone land.

Development and building controls >> Flood proofing of buildings >> Minimum Floor levels Structural measures >> Detention basins >> Permanent flood levees >> Widening of flow channels and overbank areas to allow for improved flow conveyance Land use planning >> Statutory Planning instruments (City Plan)

Residual risk associated with larger floods which exceed management measures such as works, land-use planning and development controls.

Flood emergency measures >> Flood emergency plan >> Roads with higher standards for evacuation purposes >> Reviewing emergency management facilities >> Further education of community regarding disaster preparation >> Temporary property protection measures (sandbagging)

The selection and adoption of responses for particular floodplain areas will be subject to ongoing expert analysis and community engagement. In particular, the feasibility of structural measures (new infrastructure) will be assessed against a range of economic, social and environmental impacts. In practice it is very difficult to mitigate all flood damages. Implementing structural measures requires significant capital expenditure and projects must be economically feasible to ensure return on investment. Preliminary work has identified that to provide flood mitigation across the city would cost well in excess of $500 million. This estimate suggests structural flood mitigation projects will not be economically feasible in most instances. However, there may be specific areas where structural measures are feasible. Moreover, the incorporation of flood mitigation works into other projects such as park upgrades, road upgrades and new land developments provides the best opportunity to deliver feasible flood mitigation works.

8. key actions and next steps for the

townsville floodplain management strategy The understanding of flooding gained to date forms the basis for a rigorous approach to managing flooding issues on the Townsville Floodplain. Future implementation of the the Townsville Floodplain Management Strategy will focus on progressing the following key actions, in consultation with the Townsville community. >> Review land-use practices to ensure development master plans better consider all flood risks. >> Review evacuation requirements and the suitability of available roads for evacuation to guide disaster management arrangements and prioritised road upgrades. >> Increase community awareness around the individualâ&#x20AC;&#x2122;s role in flood resilience such as awareness of risks, disaster management, uses beneath high-set homes and business continuity. >> Ensure future infrastructure planning accounts for flooding to provide the appropriate level of reliability

townsville floodplain management

Flood Hazard Analysis | Summary Report

and service in flooding events. >> Review projects in councilâ&#x20AC;&#x2122;s Capital Works Plan, including renewal works, to evaluate synergies with flood management objectives. >> Identify future Main Roads upgrade projects to evaluate synergies with flood management objectives. >> Establish partnerships with developers to evaluate synergies with broader community flood management objectives. >> Engage with the insurance industry to seek to reduce the flood damage component of premiums.

for more information: www.townsville.qld.gov.au 1300 878 001