queensland floods commission of inquiry: final report

Queensland Floods Commission of Inquiry

Final Report

March 2012

Queensland Floods Commission of Inquiry www.floodcommission.qld.gov.au

Queensland Floods Commission of Inquiry 2012

The Queensland Floods Commission of Inquiry supports and encourages the dissemination and exchange of information. However, copyright protects material in this report. The Commission has no objection to this material being reproduced but asserts its right to be recognised as author of its original material and the right to have its material remain unaltered.

Queensland Floods Commission of Inquiry

Queensland Floods Commission of Inquiry | Final Report

ContentsPreface ............................................................................................................................................................... 30 1 Introduction ................................................................................................................................................32 1.1 Report to government ........................................................................................................................... 32 1.2 The Commission of Inquiry .................................................................................................................. 33 1.3 The Commissions work ........................................................................................................................ 33 1.4 Structure of this report .......................................................................................................................... 36 1.5 General observations ............................................................................................................................. 37 2 Floodplain management ..............................................................................................................................38 2.1 Principles of floodplain management .................................................................................................... 40 2.2 Flood studies ......................................................................................................................................... 40 2.3 A flood study of the Brisbane River catchment ...................................................................................... 41 2.3.1 The expert panel..............................................................................................................................41 2.3.2 A comprehensive study of the Brisbane River catchment .................................................................42 2.3.3 Responsibility for completing the study ..........................................................................................46 2.3.4 Further investigations required for Ipswich .....................................................................................47 2.3.5 Effect of the need for a comprehensive flood study on current planning..........................................48 2.4 Brisbane and Ipswich council procedures ............................................................................................. 48 2.4.1 The Brisbane Q100 .........................................................................................................................48 2.4.2 The Ipswich Q100 ..........................................................................................................................52 2.5 The performance of flood studies in Queensland ................................................................................... 54 2.5.1 Catchment wide flood studies .........................................................................................................54 2.5.2 Who should be responsible for the performance of flood studies? ...................................................54 2.5.3 Ensuring all urban areas have flood studies......................................................................................55 2.5.4 Commissioning, assessment and use of flood studies .......................................................................56 2.5.5 Central repository of flood study data .............................................................................................58 2.6 Using flood studies in floodplain management ...................................................................................... 60 2.6.1 Preparing a floodplain management plan ........................................................................................60 2.6.2 Responsibility for floodplain management ......................................................................................60 2.6.3 Councils floodplain management activities.....................................................................................61 2.7 Flood mapping for land planning controls ............................................................................................ 62 2.7.1 The absence of flood maps in Queensland .......................................................................................62 2.7.2 The effectiveness of flood maps in land planning .............................................................................62 2.7.3 Assessment of mapping options.......................................................................................................63 2.8 Use of flood information in emergency management............................................................................. 68 2.9 Distribution of flood information ......................................................................................................... 69 2.9.1 Providing flood information and mapping to the public .................................................................69 2.9.2 Flood information for dealing with property ...................................................................................70 2.10 Guidelines for the preparation of flood studies and flood management plans ...................................... 72

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3 Planning framework ....................................................................................................................................88 3.1 State planning instruments.................................................................................................................... 88 3.1.1 Regional plans.................................................................................................................................88 3.1.2 State planning regulatory provisions ................................................................................................89 3.1.3 State planning policies ....................................................................................................................89 3.1.4 Standard planning scheme provisions ..............................................................................................89 3.2 Local planning instruments .................................................................................................................. 89 3.2.1 Planning schemes ............................................................................................................................89 3.2.2 Planning scheme policies.................................................................................................................90 3.2.3 Temporary local planning instruments ............................................................................................91 3.3 Types of development and development assessment ............................................................................. 91 3.3.1 Categories of development ..............................................................................................................91 3.3.2 Development assessment ................................................................................................................92 3.3.3 Referral agencies..............................................................................................................................93 4 State planning instruments ..........................................................................................................................96 4.1 State Planning Policy 1/03 .................................................................................................................... 96 4.1.1 The purpose and objectives of State Planning Policy 1/03 ...............................................................96 4.1.2 Application of State Planning Policy 1/03 .......................................................................................97 4.1.3 Review of State Planning Policy 1/03 ..............................................................................................99 4.1.4 State interest review of planning schemes ........................................................................................99 4.1.5 The role of the Department of Local Government and Planning ..................................................101 4.1.6 The role of the Department of Community Safety ........................................................................102 4.1.7 The role of DERM ........................................................................................................................102 4.1.8 Gaps identified..............................................................................................................................103 4.2 Temporary state planning policy ........................................................................................................ 104 4.2.1 Mapping referred to in the temporary state planning policy .........................................................104 4.2.2 The Model Code provided by the Queensland Reconstruction Authority......................................104 4.2.3 Reflecting the Temporary State Planning Policy in planning schemes ............................................105 4.3 Queensland Planning Provisions ......................................................................................................... 106 4.3.1 History of the Queensland Planning Provisions ............................................................................106 4.3.2 Structure of the Queensland Planning Provisions ..........................................................................106 4.4 Regional plans ..................................................................................................................................... 109 4.4.1 Land use designations under the South East Queensland Regional Plan ........................................109 5 Local planning instruments .......................................................................................................................118 5.1 Planning schemes ................................................................................................................................ 118 5.1.1 Model flood planning controls ......................................................................................................119 5.1.2 Features of the model flood planning controls ...............................................................................120 5.2 Temporary local planning instruments ................................................................................................ 123 5.3 Planning scheme policies..................................................................................................................... 125 5.4 Amending planning schemes ............................................................................................................... 127 5.4.1 A shorter process?..........................................................................................................................127


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5.5 Compensation ..................................................................................................................................... 128 5.5.1 Statutory immunity ......................................................................................................................128 5.5.2 Reduction in land value ................................................................................................................130 6 Satellite planning systems ..........................................................................................................................138 6.1 Urban Land Development Authority Act 2007 ..................................................................................... 138 6.2 South Bank Corporation Act 1989 ....................................................................................................... 139 6.3 State Development and Public Works Organisation Act 1971................................................................ 139 6.3.1 State development areas ................................................................................................................139 6.3.2 Significant projects ........................................................................................................................140 6.3.3 Prescribed projects ........................................................................................................................140 6.4 Consideration of flooding as part of satellite planning systems ............................................................ 141 6.4.1 Satellite planning systems generally ...............................................................................................141 6.4.2 Significant projects under the State Development and Public Works Organisation Act 1971 ........ 142 7 Development and flood considerations ......................................................................................................146 7.1 Residential uses ................................................................................................................................... 146 7.1.1 Existing residential uses .................................................................................................................146 7.1.2 An acceptable level of risk for proposed residential uses ................................................................147 7.2 Community infrastructure .................................................................................................................. 148 7.3 Commercial uses ................................................................................................................................. 151 7.4 Industrial uses and hazardous materials ............................................................................................... 153 7.4.1 Regulation ....................................................................................................................................153 7.4.2 Planning schemes ..........................................................................................................................157 7.5 River architecture ................................................................................................................................ 159 7.5.1 Brisbanes river architecture ...........................................................................................................159 7.5.2 Regulation of river architecture as prescribed tidal work ..............................................................159 7.5.3 New Farm Riverwalk ....................................................................................................................159 7.5.5 CityCat and CityFerry terminals ...................................................................................................161 7.5.6 Private pontoons ...........................................................................................................................161 7.5.7 Response to the floods...................................................................................................................161 7.6 Placement of fill and development in a floodplain ............................................................................... 162 7.6.1 Treatment of fill in State Planning Policy 1/03 and Guideline .......................................................165 7.6.2 Exemption where fill is carried out by a public sector entity ..........................................................166 7.6.3 Examples of problems from fill associated with infrastructure .......................................................167 7.7 Levees.................................................................................................................................................. 168 7.7.1 Levees in the 2010/2011 floods.....................................................................................................168 7.7.2 Post-flood consideration of levees in urban areas ...........................................................................168 7.7.3 Controlling the construction of levees ...........................................................................................169 7.7.4 Types of levees to be regulated .......................................................................................................171 7.7.5 Process and criteria for approving the construction of a levee ........................................................172 7.8 Anthills: Properties isolated by flooding of low lying access routes ...................................................... 173 7.8.1 Current provisions in State Planning Policy 1/03 ..........................................................................175

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8 Development assessment in practice ..........................................................................................................190 8.1 Sources of flood information for use in development assessment ......................................................... 192 8.1.1 Flood information maintained by councils for use in development assessment ..............................192 8.1.2 Site-specific flood information provided by an applicant ...............................................................194 8.2 Assessing flood information in development applications .................................................................... 196 8.2.1 Ipswich City Councils assessment process .....................................................................................197 8.2.2 Brisbane City Councils assessment practices .................................................................................197 8.2.3 Improving council assessment processes ........................................................................................198 8.2.4 Information requests ....................................................................................................................199 8.2.5 Problems in development assessment ...........................................................................................199 8.3 Development conditions ..................................................................................................................... 200 8.3.1 Conditions going to acceptability of use........................................................................................201 8.3.2 Standard conditions ......................................................................................................................202 8.3.3 Conditions which require flood evacuation plans ..........................................................................202 8.4 Communicating information about flood risk ..................................................................................... 203 9 Building controls .......................................................................................................................................210 9.1 Minimum floor levels .......................................................................................................................... 210 9.2 Freeboard levels ................................................................................................................................... 210 9.3 Building materials and design ............................................................................................................. 211 9.4 State versus local regulation ................................................................................................................. 212 9.5 Proposed new part of the Queensland Development Code: Construction of buildings in flood hazard areas ............................................................................................................................... 212 9.5.1 Required flood information ..........................................................................................................213 9.5.2 Assessing building applications against the proposed new part ......................................................215 9.5.3 Early adoption of the proposed new part.......................................................................................216 10 Essential services ......................................................................................................................................220 10.1 Sewage and sewerage ......................................................................................................................... 220 10.1.1 Definitions ..................................................................................................................................220 10.1.2 The role of sewerage infrastructure ..............................................................................................220 10.1.3 The regulatory structure applicable to sewerage infrastructure .....................................................221 10.1.4 The impact of the 2010/2011 floods on sewerage infrastructure .................................................221 10.1.5 The location and design of public sewerage infrastructure ...........................................................223 10.1.6 Electrical switchboards and generators .......................................................................................225 10.1.7 Prevention of sewage discharge....................................................................................................226 10.1.8 Illegal connections of stormwater to sewerage infrastructure .......................................................228 10.1.9 Interactions with disaster management groups ............................................................................230 10.2 Stormwater ....................................................................................................................................... 231 10.2.1 Overview of the stormwater network ..........................................................................................231 10.2.2 The regulatory structure applicable to stormwater networks ........................................................232 10.2.3 The design and construction of stormwater networks ..................................................................232 10.2.4 Basements ...................................................................................................................................234 10.2.5 The maintenance and optimisation of stormwater systems ..........................................................236 10.2.6 Backflow flooding .......................................................................................................................237


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10.3 Electrical infrastructure ..................................................................................................................... 239 10.3.1 The electricity supply industry in Queensland .............................................................................239 10.3.2 The impact of the 2010/2011 floods on distribution infrastructure .............................................240 10.3.3 Shared network infrastructure .....................................................................................................241 10.3.4 Customer dedicated assets ...........................................................................................................246 10.3.5 Conduits for electrical cables .......................................................................................................248 10.4 Telecommunications infrastructure ................................................................................................... 249 10.4.1 The locating of telecommunications infrastructure ......................................................................249 10.4.2 The design and protection of telecommunications infrastructure.................................................251 10.5 Roads and rail ................................................................................................................................... 252 10.5.1 Roads ..........................................................................................................................................252 10.5.2 Rail .............................................................................................................................................254 11 Buy-backs and land swaps........................................................................................................................272 11.1 Property buy-backs............................................................................................................................ 272 11.1.1 Benefits and limitations...............................................................................................................272 11.1.2 Current arrangements .................................................................................................................273 11.1.3 Council buy-back programs ........................................................................................................273 11.1.4 Future considerations ..................................................................................................................274 11.2 Rebuilding Grantham ....................................................................................................................... 275 11.2.1 Land swap program.....................................................................................................................276 11.2.2 Grantham Development Scheme ................................................................................................276 11.2.3 Suitability of the Grantham response for other areas ...................................................................277 12 Performance of private insurers ...............................................................................................................282 12.1 Other reviews .................................................................................................................................... 282 12.2 Insurers claims responsibilities.......................................................................................................... 284 12.2.1 Terms of the policy and the general law of insurance ..................................................................284 12.2.2 The Insurance Contracts Act 1984 ............................................................................................ 285 12.2.3 General Insurance Code of Practice.............................................................................................285 12.2.4 Topics of investigation for the Commission.................................................................................286 12.3 Process of investigation ..................................................................................................................... 286 12.3.1 Co-operation of insurers .............................................................................................................287 12.3.2 Insurance statistics ......................................................................................................................288 12.3.3 The body of evidence ..................................................................................................................289 12.4 The picture as a whole ....................................................................................................................... 289 12.4.1 The number of claims .................................................................................................................289 12.4.2 Accepted versus declined claims ..................................................................................................290 12.4.3 Disputed claims ..........................................................................................................................292 12.5 Timeliness......................................................................................................................................... 294 12.5.1 Determination of liability ...........................................................................................................294 12.5.2 Finalisation of accepted claims: settlement, replacement and repairs ...........................................298 12.5.3 Timeliness of internal dispute resolution .....................................................................................300 12.6 Communication with policy-holders ................................................................................................. 302 12.6.1 Multiple case managers ...............................................................................................................303 12.6.2 File notes and recording calls.......................................................................................................303 12.7 Assessment process ............................................................................................................................ 304 12.7.1 Area hydrology reports ................................................................................................................304

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12.7.2 Site-specific hydrology reports .....................................................................................................306 12.7.3 Loss assessors reports ..................................................................................................................307 12.7.4 CGUs desktop assessment process ..............................................................................................309 12.7.5 RACQ Insurance Limited ...........................................................................................................319 12.8 Information to policy-holders whose claims were denied ................................................................... 321 12.8.1 Provision of reasons.....................................................................................................................321 12.8.2 Provision of information .............................................................................................................323 12.9 Internal dispute resolution ................................................................................................................ 324 13 Mining .....................................................................................................................................................350 13.1 Preparation for the 2010/2011 wet season ........................................................................................ 352 13.1.1 Response to Bureau of Meteorology seasonal forecast ..................................................................352 13.1.2 Pre-wet season inspections...........................................................................................................353 13.2 Flooding at mine sites ...................................................................................................................... 354 13.3 Effects of mine discharges.................................................................................................................. 356 13.4 Environmental authorities ................................................................................................................. 357 13.4.1 The legislative regime ..................................................................................................................357 13.4.2 The Fitzroy model conditions......................................................................................................357 13.4.3 The effect of the model conditions on water storage on site .........................................................358 13.4.4 The industry pushes for amendments ..........................................................................................359 13.4.5 Performance of environmental authorities in the 2010/2011 wet season .....................................359 13.4.6 Changes in the wake of the flood ................................................................................................359 13.5 Transitional environmental programs ............................................................................................... 361 13.5.1 DERMs approach to granting transitional environmental programs in the 2010/2011 wet season ...................................................................................................................................362 13.5.2 The need for timely approvals .....................................................................................................362 13.5.3 Consistency of decision-making ..................................................................................................363 13.5.4 A proper use of transitional environmental programs? ................................................................365 13.5.5 Adequacy of DERMs response to flooding .................................................................................366 13.6 A third way emergency directions? ................................................................................................. 367 13.6.1 The Moranbah North emergency direction .................................................................................367 13.6.2 Definition of emergency .............................................................................................................368 13.6.3 Procedural guide .........................................................................................................................368 13.6.4 Verbal approvals .........................................................................................................................368 13.7 Maintaining the experience gained in 2010/2011.............................................................................. 369 13.8 Abandoned mines.............................................................................................................................. 369 13.8.1 Effect of flooding on abandoned mines .......................................................................................369 13.8.2 The abandoned mine land program.............................................................................................371 13.8.3 Mt Oxide mine (abandoned) ......................................................................................................371 13.8.4 Taking responsibility for abandoned mines..................................................................................372 13.8.5 Steps in the management of abandoned mines ............................................................................372 14 Flood-related deaths ................................................................................................................................386 14.1 The Commissions review of systemic issues....................................................................................... 386 14.2 The circumstances of 2010/2011 flood-related deaths ....................................................................... 386 14.2.1 Deaths during activities in flooded waterways .............................................................................387 14.2.2 Deaths of people in vehicles on flooded roads and crossings ........................................................387 14.2.3 The deaths in flash flooding in Toowoomba on 10 January 2011 ................................................389


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14.2.4 The deaths in the Lockyer Valley region on 10 January 2011 ......................................................390 14.2.5 Death of a child during a rescue attempt on 11 January 2011 .....................................................392 15 Emergency response and other interim report issues................................................................................394 15.1 Evacuation plans for commercial premises ......................................................................................... 394 15.2 Emergency communications.............................................................................................................. 397 15.2.1 Interoperability ...........................................................................................................................397 15.2.2 Radio communications black spots............................................................................................399 15.3 Review of disaster management plans................................................................................................ 400 15.3.1 The review process ......................................................................................................................400 15.3.2 Assessment of the review process .................................................................................................401 15.4 Queensland Fire and Rescue Service .................................................................................................. 402 15.4.1 Preparedness for and response to the events of 10 January 2011 ..................................................402 15.4.2 Response of fire service management and deployments on 10 January ...................................................................................................................................402 15.4.3 Chain of command .....................................................................................................................405 15.4.4 Weather forecasts and warnings ...................................................................................................406 15.4.5 Risk assessments ..........................................................................................................................406 15.5 State Emergency Service (SES) .......................................................................................................... 407 15.5.1 SES command and control..........................................................................................................407 15.5.2 Funding ......................................................................................................................................415 15.5.3 RFA Online ................................................................................................................................417 15.5.4 Training ......................................................................................................................................417 15.5.5 Shared responsibility ...................................................................................................................418 15.6 State Emergency Service in Grantham ............................................................................................... 418 15.7 The Grantham quarry........................................................................................................................ 419 16 Operation of Wivenhoe and Somerset dams ............................................................................................436 16.1 Overview ........................................................................................................................................... 438 16.2 The flood mitigation manual for Wivenhoe Dam and Somerset Dam................................................ 442 16.3 The manual requires a choice of strategy ........................................................................................... 443 16.3.1 Objectives and procedures...........................................................................................................443 16.3.2 The role of the flood engineers ....................................................................................................444 16.3.3 Selection of flood operations strategies .......................................................................................445 16.3.4 Move to strategy W3 mandated by the manual ...........................................................................447 16.3.5 Does the manual require that an engineer be conscious of the strategy in which he is operating? ......450 16.4 The flood engineers evidence as to the manuals requirements for adoption of strategies generally .... 451 16.5 The March flood event report: a record of strategy choice .................................................................. 452 16.5.1 The executive summary ...............................................................................................................453 16.5.2 Express statements as to strategy selection ..................................................................................453 16.6 Evidence of strategy choice: the flood operations engineers ............................................................... 457 16.6.1 Mr Ruffini ..................................................................................................................................457 16.6.2 Mr Ayre ......................................................................................................................................459 16.6.3 Mr Tibaldi ..................................................................................................................................462 16.6.4 Mr Malone .................................................................................................................................462 16.7 Objective evidence as to strategy choice on 8 and 9 January 2011 ..................................................... 463 16.7.1 Documents from which no inference as to strategy can be drawn ................................................464

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16.7.2 Situation report at 5.53 pm on 8 January 2011 ...........................................................................474 16.7.3 Flood event log, 3.30 pm, 9 January ..........................................................................................478 16.7.4 Situation Report at 9.04 pm, telephone conference at 9.30 pm, and emails from Mr Spiller at 11.07 pm on 9 January 2011..................................................................................482 16.7.5 Mr Drurys email to Mr Spiller on the morning of 10 January 2011 ...........................................482 16.7.6 Teleconference at 8.30am on 10 January 2011 ...........................................................................483 16.7.7 Mr Allens email to Mr Cooper at 10.57am on 12 January 2011 .................................................484 16.7.8 Conclusion on contemporaneous documents ..............................................................................485 16.8 The first attempts to record strategy choice ....................................................................................... 485 16.8.1 Mr Malones Summary of Manual document ..............................................................................485 16.8.2 Strategy Summary Log ................................................................................................................487 16.8.3 The brief for the Minister ............................................................................................................491 16.8.4 Conclusions from Summary of Manual, Strategy Summary Log and the brief for the Minister ...495 16.8.5 Another record - Mr Ayres gate operations spreadsheet comments..............................................495 16.9 Another record: Mr Coopers report ................................................................................................. 496 16.10 The March 2011 flood event report ................................................................................................. 497 16.10.1 The role of the flood engineers ..................................................................................................497 16.10.2 Mr Tibaldis methodology .........................................................................................................498 16.10.3 Other flood engineers involvement in and adoption of sections 2 and 10 .................................501 16.11 Conclusions: the dam operations strategies ..................................................................................... 503 16.11.1 The strategies used ....................................................................................................................503 16.11.2 The engineers states of mind about strategy changes .................................................................504 16.11.3 Engineers states of mind ..........................................................................................................505 16.11.4 Knowledge of each others actions and state of mind .................................................................507 16.11.5 Referral to the Crime and Misconduct Commission .................................................................509 16.11.6 Seqwaters systems and procedures for the creation of the flood event report .............................509 16.12 Knowledge of government officials about the March flood event report........................................... 511 16.12.1 Peter Allen, Director, Dam Safety .............................................................................................511 16.12.2 Knowledge of Seqwater management ........................................................................................513 16.12.3 Knowledge of the Premier, the responsible Minister and the Directors-General.........................514 16.12.4 Knowledge of officers of the SEQ Water Grid Manager ............................................................517 16.13 Peer reviews of the March report ..................................................................................................... 519 16.14 The effect of releases from Wivenhoe Dam on flooding in the Brisbane River ................................ 521 16.14.1 Modelling work done for the Commission ................................................................................522 16.14.2 The effect of the operation of Wivenhoe Dam in January 2011 .................................................522 16.14.3 Effects of different release strategies ...........................................................................................524 17 Other dam issues......................................................................................................................................560 17.1 Longer term review of the Wivenhoe and North Pine manuals .......................................................... 561 17.1.1 The structure for the completion of the scientific investigations ..................................................561 17.1.2 Consideration of options for operating strategies by government ................................................563 17.1.3 Creation of the new manuals.......................................................................................................564 17.1.4 A further consideration for the longer term review of the North Pine manual .............................569 17.2 Review and approval of flood mitigation manuals ............................................................................. 570 17.2.1 Identity of approver ....................................................................................................................570 17.2.2 Independence of assessor .............................................................................................................570 17.2.3 Work procedure ..........................................................................................................................571 17.3 Review of flood event reports ............................................................................................................ 572


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17.4 Bank slumping .................................................................................................................................. 574 17.4.1 Riverbank erosion and slumping in January 2011 .......................................................................574 17.4.2 The causes of riverbank erosion and slumping .............................................................................575 17.4.3 Slumping in the upper-Brisbane River ........................................................................................576 17.4.4 Slumping in mid-Brisbane River .................................................................................................577 17.4.5 Riverbank slumping and dam operation strategies.......................................................................578 17.5 Wivenhoe Power Station ................................................................................................................... 579 17.5.1 Splityard Creek Dam ..................................................................................................................579 17.5.2 Interaction between Splityard Creek Dam and Wivenhoe Dam ..................................................579 17.5.3 Wivenhoe Power Station during the January 2011 flooding ........................................................580 17.5.4 Communication about releases ...................................................................................................581 17.5.5 Flood emergency planning ..........................................................................................................582 17.5.6 Condition of Splityard Creek Dam .............................................................................................583 17.5.7 Control of Splityard Creek Dam operations during flooding .......................................................583 17.6 Somerset Dam cracks ........................................................................................................................ 584 17.6.1 Investigating the cracks ...............................................................................................................585 17.6.2 Monitoring the cracking .............................................................................................................586 17.6.3 Impact of the cracking on the operation of Somerset Dam during floods ....................................587 17.7 Bridges and crossings near Wivenhoe, Somerset and North Pine dams .............................................. 588 17.7.1 Crossings downstream of Wivenhoe, Somerset and North Pine dams .........................................588 17.7.2 Upgrading bridges and influence on dam operations ...................................................................589 17.7.3 Communication of bridge closures..............................................................................................590 17.8 Lenthalls Dam................................................................................................................................... 591 17.8.1 Installation and design of the crest gates ......................................................................................591 17.8.2 Chronology of floods since installation of the gates .....................................................................592 17.8.3 Observed problems and solutions implemented ..........................................................................594 17.8.4 Current status of gate operability ...............................................................................................595 17.8.5 Dam safety implications ..............................................................................................................596 17.8.6 Preparing for wet seasons ............................................................................................................596 17.9 Detention basins in Toowoomba city ................................................................................................ 597 17.9.1 Flood mitigation actions by Toowoomba Regional Council ........................................................597 17.9.2 DERMs dam safety and failure impact assessment......................................................................598 17.10 Other DERM dam functions .......................................................................................................... 599 17.10.1 Response to Bureau of Meteorology forecast .............................................................................599 17.10.2 Review and approval of emergency action plans ........................................................................600 17.10.3 Dam safety audits .....................................................................................................................602 17.10.4 Interaction between DERM and disaster management personnel ..............................................603 17.10.5 Management of non-commercial water assets ............................................................................603 17.10.6 A broader flood mitigation responsibility? .................................................................................604 Appendices....................................................................................................................................................622 Appendix 1: Terms of Reference ................................................................................................................ 623 Appendix 2: Leave to appear...................................................................................................................... 628 Appendix 3: Interim Report recommendations ............................................................................................ 630 Appendix 4: List of staff at the Commission .............................................................................................. 643 Appendix 5: List of experts engaged by the Commission ........................................................................... 644 Appendix 6: Glossary ................................................................................................................................ 645

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Complete list of Final Report recommendations

Chapter 2 Floodplain management2.1 The steering committee of the Wivenhoe Dam and Somerset Dam Optimisation Study should consider whether it would be more effective for the floodplain management investigation to be removed from the Wivenhoe Dam and Somerset Dam Optimisation Study. Brisbane City Council, Ipswich City Council and Somerset Regional Council and the Queensland Government should ensure that, as soon as practicable, a flood study of the Brisbane River catchment is completed in accordance with the process determined by them under recommendation 2.5 and 2.6. The study should: be comprehensive in terms of the methodologies applied and use different methodologies to corroborate results involve the collation, and creation where appropriate, of the following data: rainfall data including historical and design data and radar stream flow data tide levels inundation levels and extents data on the operation of Wivenhoe and Somerset dams river channel and floodplain characteristics including topography, bathymetry, development and survey data

2.2

involve determining the correlation between any of the data sets above produce suitable hydrologic models run in a Monte Carlo framework, taking account of variability over the following factors: spatial and temporal rainfall patterns saturation of the catchment initial water level in dams effect of operating procedures physical limitations on the operation of the dams tidal conditions closely occurring rainfall events observed hydrograph attenuation probability distributions of observed values for total flood volume and peak flow timing of major tributary flows observed flood behaviour under no dams conditions and current conditions are able to determine flood heights, extents of inundation, velocities, rate of rise and duration of inundation for floods of different probabilities

validate hydrologic models to ensure they reproduce:

produce a suitable hydraulic model or models that:

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are able to deal with movement of sediment and changes in river beds during floods are able to assess historical changes to river bathymetry are able to be run in a short time to allow detailed calibration and assessment work characterise the backwater effect at the confluence of the Brisbane and Bremer rivers and other confluences as appropriate

involve analysis of the joint probability of floods occurring in the Brisbane and Bremer rivers (and any other pair of rivers if considered appropriate) be iterative, and obtain a short-term estimate of the characteristics of floods of different probabilities in all significant locations in the catchment (at least Brisbane City, Ipswich City and at Wivenhoe Dam) in order to determine the priorities for the rest of the study.

2.3

Ipswich City Council should determine whether the results, models and maps produced by the Brisbane River flood study are sufficient for its floodplain management. If they are not, Ipswich City Council should ensure appropriate work is done by way of data collection and creation and hydrologic and hydraulic modelling for use in its floodplain management. A recent flood study should be available for use in floodplain management for every urban area in Queensland. Where no recent study exists, one should be initiated. The Queensland Government, in consultation with councils, should determine which urban areas in Queensland do not have access to flood information from a current flood study. The Queensland Government should rank those areas in order of priority in accordance with their need for updated flood information by reference to factors including: a. b. c. d. population sophistication of land use planning and emergency management measures already in place in those areas currency of any flood risk information available to the council approximate frequency of damaging floods in the area according to the historical record.

2.4 2.5

2.6

By reference to the order of priority determined in accordance with recommendation 2.5, the Queensland Government and councils should together ensure that the council responsible for each urban area in Queensland has access to current flood study information. This will include determining: a. b. c. a process or processes by which the flood studies will be completed, including the involvement of the Queensland Government and relevant councils how, and from whom, the necessary technical and financial resources will be obtained a reasonable timeframe by which all flood studies required will be completed.

2.7 2.8

As far as is practicable, councils should maintain up-to-date flood information. When commissioning a flood study, the body conducting the study should: check whether others, such as surrounding councils which are not involved in the study, dam operators, the Department of Environment and Resource Management, and the Bureau of Meteorology, are doing work that may assist the flood study or whether any significant scientific developments are expected in the near future, and decide whether to delay the study discuss the scope of work with the persons to perform the flood study as well as surrounding councils which are not involved in the study, dam operators, the Department of Environment and Resource Management, and the Bureau of Meteorology.

2.9 2.10

Elected representatives from councils should be informed of the results of each flood study relevant to the councils region, and consider the ramifications of the study for land planning and emergency management. Elected representatives from all agencies involved in a flood study should be informed of recommendations made for future work, and determine, on a risk basis, whether that further work is to be completed.


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2.11

The Queensland Government and Commonwealth Government should ensure the existence and maintenance of a repository of data of the type used in flood studies. The database should include the types of data which the expert panel specified as needed for a comprehensive flood study. Councils, Queensland and Commonwealth Government agencies and dam operators should be able to deposit and obtain access to data. Councils in floodplain areas should, resources allowing, develop comprehensive floodplain management plans that accord as closely as practicable with best practice principles. For urban areas or areas where development is expected to occur: a. b. councils with the requisite resources should develop a flood map which shows zones of risk (at least three) derived from information about the likelihood and behaviour of flooding councils without the requisite resources to produce a flood behaviour map should develop a flood map which shows the extent of floods of a range of likelihoods (at least three).

2.12 2.13

2.14

For non-urban areas or areas where limited development is expected to occur councils should consider, on a risk basis, what level of information about flood risk is required for the area, and undertake the highest ranked of the following options which is appropriate to that need and within the capacities (financial and technical) of the council: a. b. c. d. e. f. a map showing zones of risk (at least three) derived from information about the likelihood and behaviour of flooding a map showing the extent of floods of a range of likelihoods (at least three) a flood map based on historic flood levels that have been subjected to a flood frequency analysis to estimate the annual exceedance probability of the selected historical flood a historic flood map without flood frequency analysis the Queensland Reconstruction Authority Interim Floodplain Assessment Overlay as a way to determine those areas for which further flood studies are required, or the Queensland Reconstruction Authority Interim Floodplain Assessment Overlay (preferably refined using local flood information) as a trigger for development assessment.

2.15

Councils should ensure that areas for which there has been no assessment of the likelihood of flooding are indicated on a map and that, as part of the development assessment process for these, there is at least some enquiry into whether a site proposed for development could be subject to flooding. Councils and the Queensland Government should display on their websites all flood mapping they have commissioned or adopted. Flood maps, and property specific flooding information intended for use by the general public, should be readily interpretable and should, where necessary, be accompanied by a comprehensible explanatory note. Councils that do not currently do so should consider offering an online database which allows the public to conduct a search on a parcel of land to find development approvals relevant to that parcel of land. The Queensland Government should consider implementing a mechanism by which prospective purchasers of property are alerted to the issue of flood risk. To that end, the Queensland Government should consider consulting the Real Estate Institute of Queensland and the Law Society of Queensland as to the appropriateness of amending standard contract conditions so as to include a subject to flood search condition, or other means of achieving the same objective. The Queensland Government should endeavour to ensure that Queensland conditions are appropriately considered in the National Flood Risk Advisory Groups review of best practice principles. In the event that the review does not adequately account for Queensland conditions, the Queensland Government should produce a document that provides appropriate guidelines for floodplain management in the Queensland context. The Queensland Government should determine whether existing guidelines are sufficient for councils to understand best practice in the performance of flood studies and the production of flood maps. If a lack of current guidelines is identified, the government should create and circulate guidance material for councils.

2.16 2.17 2.18 2.19

2.20 2.21

2.22

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Chapter 4 State planning instruments4.1 The Queensland Government should: a. narrow the definition of development commitment in State Planning Policy 1/03: Mitigating the Adverse Impacts of Flood, Bushfire and Landslide to ensure more development applications are assessed for compatibility with flood, and investigate whether the compensation provisions of the Sustainable Planning Act 2009 act as a deterrent to the inclusion of flood controls in a planning scheme and consider whether they ought be amended.

b. 4.2

If, as part of a state interest review process, the Department of Local Government and Planning decides that no condition should be imposed requiring a councils proposed planning scheme to incorporate the effect of the Department of Community Safetys comments about State Planning Policy 1/03: Mitigating the Adverse Impacts of Flood, Bushfire and Landslide, it should advise the Department of Community Safety of the reasons for its decision. The Department of Community Safety should put in place administrative arrangements which ensure it can readily ascertain whether its comments are being reflected in council planning schemes. If the Department of Community Safety becomes aware that its comments are not being adequately addressed, it should take steps to follow this up with the Department of Local Government and Planning. The Queensland Government should ensure that the circumstances in which the Department of Community Safety is to consult the Department of Environment and Resource Management about a planning schemes flood modelling and flood mapping are clear. The Queensland Government should change Temporary State Planning Policy 2/11: Planning for stronger more resilient floodplains to remove the possibility of councils using the interim floodplain assessment overlay mapping and Model Code as part of a permanent amendment to their existing planning scheme or as part of a new planning scheme. Councils should consider using the limited development (constrained land) zone in their planning schemes for areas that have a very high flood risk. The Queensland Government should consider amending the Sustainable Planning Act 2009 to require that consideration be given to the risk of flooding in the preparation or revision of a regional plan.

4.3

4.4

4.5

4.6 4.7

Chapter 5 Local planning instruments5.1 The Queensland Government should draft model flood planning controls, using a similar format and structure to that in the Queensland Planning Provisions, that councils can adapt for local conditions. The Queensland Government should require these controls to be reflected in new planning schemes. This may be achieved by including the controls in either: a state planning policy dealing with flood, with an accompanying amendment to the Sustainable Planning Act 2009, or the Queensland Planning Provisions.

The Queensland Government should consult councils to determine which of the two state planning instruments is the more appropriate to include the model flood planning controls. 5.2 The Queensland Government should include in the model flood planning controls a requirement that councils have a flood overlay map in their planning schemes. The map should identify the areas of the council region: that are known not to be affected by flood that are affected by flood and on which councils impose planning controls (there may be subsets in each area to which different planning controls attach) for which there is no flood information available to council.


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5.3

If the Queensland Government does not include a requirement for such an overlay map in the model flood planning controls, councils should include a flood overlay map in their planning schemes. The map should identify the areas of a council region: that are known not to be affected by flood that are affected by flood and on which councils impose planning controls (there may be subsets in each area to which different planning controls attach) for which there is no flood information available to council.

5.4 5.5

The Queensland Government should include in the model flood planning controls a model flood overlay code that consolidates assessment criteria relating to flood. If the Queensland Government does not include such a code in the model flood planning controls, councils should include in their planning schemes a flood overlay code that consolidates assessment criteria relating to flood. The Queensland Government should include in the model flood planning controls a model planning scheme policy that: for development proposed on land susceptible to flooding, outlines what additional information an applicant should provide to the assessment manager as part of the development application, or for development proposed on land where the potential for flooding is unknown, requires an applicant to provide: as part of the development application, information to enable an assessment of whether the subject land is susceptible to flooding, and upon a determination the subject land is susceptible to flooding, more detailed information, to allow an assessment of the flood risk.

5.6

5.7

If the Queensland Government does not include such a policy in the model flood planning controls, councils should include in their planning schemes a planning scheme policy that: for development proposed on land susceptible to flooding, outlines what additional information an applicant should provide to the assessment manager as a part of the development application, or for development proposed on land where potential for flooding is unknown requires an applicant to provide: as part of the development application, information to enable an assessment of whether the subject land is susceptible to flooding, and upon a determination the subject land is susceptible to flooding, more detailed information to allow an assessment of the flood risk.

5.8

The Queensland Government should consider amending the Sustainable Planning Act 2009 to expressly provide either a power to remake or a power to extend a temporary local planning instrument containing interim flood regulation for a further limited period. The power to remake or extend should: a. permit the modification of the temporary local planning instrument to the extent required to ensure its provisions remain relevant, having regard to any requirement that may have been introduced or any information that may have become available while the original temporary local planning instrument was in force be contingent on the Ministers being satisfied that the circumstances listed in section 105 of the Sustainable Planning Act continue to exist and that there are proper grounds for the failure to make a permanent scheme amendment while the original temporary local planning instrument was in force.

b.

5.9

The Queensland Government should consider allowing councils to amend a planning scheme to update existing flood mapping information by way of the minor amendment process, provided that adequate public consultation has occurred.

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Chapter 6 Satellite planning systems6.1 The Queensland Government should consider amending the Urban Land Development Authority Act 2007, the South Bank Corporation Act 1989, the State Development and Public Works Organisation Act 1971 insofar as it governs state development areas, and other legislation which establishes alternative planning systems that operate independently of the Sustainable Planning Act 2009, to require that: 6.2 any planning scheme, interim or otherwise, appropriately reflects any state planning policy with respect to flood flood risk be considered in the assessment of any development application.

The Coordinator-General should amend the guideline for preparing an initial advice statement for a significant project under the State Development and Public Works Organisation Act 1971 so that it specifically requires an applicant to consider and provide information about the projects flood risk.

Chapter 7 Development and flood considerations7.1 The Queensland Government should consider extending the application of a state planning policy dealing with flood to the types of community infrastructure which are identified in the Sustainable Planning Regulation 2009 and which the community needs to continue functioning, notwithstanding flood. The Queensland Government should draft assessment criteria to be included in the model flood planning controls that require community infrastructure (including the types of community infrastructure which are identified in the Sustainable Planning Regulation 2009 and which the community needs to continue functioning, notwithstanding flood) to be located and designed to function effectively during and immediately after a flood of a specified level of risk. If the Queensland Government does not include such assessment criteria in model flood planning controls, councils should include assessment criteria in their planning schemes that require community infrastructure (including the types of community infrastructure which are identified in the Sustainable Planning Regulation 2009 and which the community needs to continue functioning, notwithstanding flood) to be located and designed to function effectively during and immediately after a flood of a specified level of risk. The Queensland Government should draft assessment criteria to be included in the model flood planning controls that require the impact of flood on commercial property to be minimised. If the Queensland Government does not include such assessment criteria in the model flood planning controls, councils should include assessment criteria in their planning schemes that require the impact of flood on commercial property to be minimised. The Queensland Government should ensure that the criteria under the Environmental Protection Act 1994 that apply to the assessment of development applications for material change of use for environmentally relevant activities include consideration of the risk of flooding at the site on which the activity is proposed to occur. The Department of Environment and Resource Management should amend its information sheet about applications for a material change of use for environmentally relevant activities so that applicants are prompted to include information (if any) about the risk of flooding at the site where the activity is proposed to occur. The Department of Environment and Resource Management should amend the template assessment report used to assess applications for a material change of use for environmentally relevant activities so that it prompts departmental officers to give specific consideration, as part of the assessment process, to the risk of flooding at the site where the activity is proposed to occur. The Department of Environment and Resource Management should ensure that, when applications for a material change of use for an environmentally relevant activity are approved by the department, the details of those activities, including their nature and location, are provided to the council within whose area the activity will be conducted.

7.2

7.3

7.4 7.5

7.6

7.7

7.8

7.9


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7.10

Councils should ensure that, when applications for environmentally relevant activities are approved by a council, the details of those activities, including their nature and location, are provided to the Department of Environment and Resource Management. The Queensland Government should draft assessment criteria to be included in the model flood planning controls that require that: a. b. the manufacture or storage of bulk hazardous materials (as defined in State Planning Policy 1/03) take place above a certain flood level, determined following an appropriate risk based assessment, or structures on land susceptible to flooding and used for the manufacture or storage of bulk hazardous materials (as defined in State Planning Policy 1/03) be designed to prevent the intrusion of floodwaters.

7.11

7.12

If the Queensland Government does not include such assessment criteria in the model flood planning controls, councils should include assessment criteria in their planning schemes that require that: a. b. the manufacture or storage of bulk hazardous materials (as defined in State Planning Policy 1/03) take place above a certain flood level, determined following an appropriate risk based assessment, or structures on land susceptible to flooding and used for the manufacture or storage of bulk hazardous materials (as defined in State Planning Policy 1/03) be designed to prevent the intrusion of floodwaters.

7.13

When approving applications for development which involve the manufacture or storage of hazardous materials, councils should not restrict the conditions imposed to ones which are solely reliant on human intervention to remove the materials in the event of flood. The Queensland Government should review the code for development applications for prescribed tidal work in the Coastal Protection and Management Regulation 2003 to consider whether the design and construction standards should be made more stringent than the existing standards. Councils (particularly Brisbane City Council) should consider including in their planning schemes more stringent standards for the design and construction of prescribed tidal work than those in the code for development applications for prescribed tidal work in the Coastal Protection and Management Regulation 2003. The Queensland Government should consider drafting assessment criteria to be included in the model flood planning controls which require that works in a floodplain: do not reduce on-site flood storage capacity counteract any changes the works will cause to flood behaviour of all floods up to and including the applicable defined flood event by measures taken within the subject site (for example, use of compensatory works, detention basins or other engineering mechanisms) do not change the flood characteristics outside the subject site in ways that result in: loss of flood storage loss of/changes to flow paths acceleration or retardation of flows, or any reduction in flood warning times elsewhere on the floodplain.

7.14

7.15

7.16

7.17

If the Queensland Government does not include such assessment criteria in the model flood planning controls, councils should consider including assessment criteria in their planning schemes which require that works in a floodplain: do not reduce on-site flood storage capacity counteract any changes the works will cause to flood behaviour of all floods up to and including the acceptable defined flood event by measures taken within the subject site (for example, use of compensatory works, detention basins or other engineering mechanisms), and do not change the flood characteristics outside the subject site in ways that result in: loss of flood storage loss of/changes to flow paths acceleration or retardation of flows, or any reduction in flood warning times elsewhere on the floodplain.

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7.18

The Queensland Government should consider amending the Sustainable Planning Regulation 2009 so that operational work or plumbing or drainage work (including maintenance and repair work) carried out by or on behalf of a public sector entity authorised under a state law to carry out the work is not exempt development under the Sustainable Planning Act 2009 if the development has the potential to reduce floodplain storage. Levees should be regulated. The Queensland Government should consult with councils to determine an effective method for the regulation of the construction of levees in Queensland. In particular, the Queensland Government should consider: requiring a development permit for the construction of a levee by designating levees as assessable development in the Sustainable Planning Regulation 2009, or requiring, by way of a state planning policy or mandatory provision in the Queensland Planning Provisions, that councils nominate the construction of a levee as assessable development in their planning schemes.

7.19 7.20

7.21 7.22

The Queensland Government should consult with councils to formulate a definition of levee to identify what should be regulated. There should be a consistent process for the determination of applications to build levees. That process should include: consulting landholders who may be affected by the proposed levee obtaining or commissioning appropriate hydrological and hydraulic studies to assess the impacts of the proposed levee.

7.23

There should be a common set of considerations in the decision whether to approve an application to build a levee, including: the impacts of the proposed levee on the catchment as a whole the benefits of the proposed levee to the individual or entity applying to build the levee and to any nearby community as a whole any adverse impacts on other landholders, including the risk of levee failure the implications of the proposed levee for land planning and emergency management procedures whether any structural, land planning or emergency management measures can be taken to mitigate the adverse impacts of the proposed levee.

7.24

The Queensland Government should draft assessment criteria to be included in the model flood planning controls that address: the prospect of isolation or hindered evacuation the impact of isolation or hindered evacuation.

7.25

If the Queensland Government does not include such assessment criteria in the model flood planning controls, councils should consider including assessment criteria in their planning schemes that address: the prospect of isolation or hindered evacuation the impact of isolation or hindered evacuation.

Chapter 8 Development assessment in practice8.1 Councils should, resources allowing, maintain flood maps and overland flow path maps for use in development assessment. For urban areas these maps should be based on hydraulic modelling; the model should be designed to allow it to be easily updated as new information (such as information about further development) becomes available. Councils should make their flood and overland flow maps and models available to applicants for development approvals, and to consultants engaged by applicants.

8.2


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8.3

The Queensland Government should draft a model planning scheme policy to be included in the model flood planning controls that sets out the information to be provided in development applications in relation to stormwater and flooding. The policy should specify: the type of models and maps to be provided the substantive information required to be shown in the development application how the assumptions and methodologies used in preparing the models and maps should be presented the form in which the information on stormwater and flooding is to be presented in the application.

8.4

If the Queensland Government does not include such a policy in the model flood planning controls, councils should include a planning scheme policy in their planning schemes that sets out the information to be provided in development applications in relation to stormwater and flooding. The policy should specify: the type of models and maps to be provided the substantive information required to be shown in the development application how the assumptions and methodologies used in preparing the models and maps should be presented the form in which the information on stormwater and flooding is to be presented in the application.

8.5

Councils should review their assessment processes to ensure that: the person with primary responsibility for the assessment of the development application considers what expert input is required where a development application is subject to comment by a number of professionals, the responsibilities and accountability of each contributor are clear where flood-related information is referred to an expert for advice, the expert is required to comment on the extent of compliance by reference to each relevant assessment criteria and identify and explain any inability to comment.

8.6

Councils should take care when imposing conditions to ensure that each condition has purpose; standardised conditions should not be included where they have no application to the development in question. Councils should not rely on a condition requiring an evacuation plan as the sole basis for approving a development susceptible to flooding. Councils should consider providing advice to development applicants during pre-lodgement meetings, and at the time of receiving a development application, about the way in which the development will be assessed for flood risk and what flood information council will be relying on to make this assessment.

8.7 8.8

Chapter 9 Building controls9.1 The proposed new part of the Queensland Development Code, Mandatory Part 3.5 Construction of buildings in flood hazard areas, should be amended so that the performance requirement relating to building design and construction (Performance Requirement P1) for building on a lot will only be triggered where the council has: designated part of its area as a natural hazard management area (flood) under section 13 of the Building Regulation 2006, and either: declared a height to be the expected flood level under section 13 of the Building Regulation 2006, or adopted a highest recorded flood level for the lot, and declared a velocity to be the expected maximum velocity of flood water for the area in which the lot is located, or designated the area in which the lot is located an inactive flow or backwater area.

either:

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9.2

The proposed new part of the Queensland Development Code, Mandatory Part 3.5 Construction of buildings in flood hazard areas, should be amended so that the performance requirements about utilities and sanitary drains (Performance Requirement P2 and P3) for building on a lot will only be triggered where the council has: designated part of its area as a natural hazard management area (flood) under section 13 of the Building Regulation 2006, and either: declared a height to be the expected flood level under section 13 of the Building Regulation 2006, or adopted a highest recorded flood level for the lot.

9.3

The Queensland Government should consider amending the Limitation section of the proposed new part of the Queensland Development Code, Mandatory Part 3.5 Construction of