Leichhardt Estuarine Planning Levels Study
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Estuarine Planning Levels Study Foreshore Region of Leichhardt Local Government Area LJ2611/R2358 Prepared for Leichhardt Municipal Council 1 April 2010 Estuarine Planning Levels Study – Foreshore Region of Leichhardt Local Government Area Prepared for Leichhardt Municipal Council Cardno (NSW) Pty Ltd Trading as Cardno Lawson Treloar Pty Ltd ABN 95 001 145 035 Level 2, 910 Pacific Highway Gordon NSW 2072 Australia Telephone: 02 9499 3000 Facsimile: 02 9499 3033 International: +61 2 9499 3000 www.cardno.com.au Report No:_____ Document Control Version Status Date Author Reviewer 1 Draft 25 May 2007 Sean Garber SJG Doug Treloar PDT 2 Draft 25 June 2007 Sean Garber SJG Doug Treloar PDT 3 Draft 17 September 2007 Sean Garber SJG Doug Treloar PDT 12 February 2009 Sean Garber SJG Doug Treloar PDT 4 Draft 5 Final 1 April 2010 Sean Garber Doug Treloar "© 2010 Cardno (NSW) Pty Ltd Trading as Cardno Lawson Treloar Pty Ltd All Rights Reserved. Copyright in the whole and every part of this document belongs to Cardno (NSW) Pty Ltd Trading as Cardno Lawson Treloar Pty Ltd and may not be used, sold, transferred, copied or reproduced in whole or in part in any manner or form or in or on any media to any person without the prior written consent of Car dno (NSW) Pty Ltd Trading as Cardno Lawson Treloar Pty Ltd.” 1 April 2010 Cardno Lawson Treloar Pty Ltd i H:\Doc\2010\Reports.2010\Rep2358v5.doc Estuarine Planning Levels Study – Foreshore Region of Leichhardt Local Government Area Prepared for Leichhardt Municipal Council Table of Contents 1 Introduction ...................................................................................................................................1 2 Objectives ......................................................................................................................................2 3 Review of Current Practices ........................................................................................................3 4 Physical Processes.......................................................................................................................6 4.1 Waves....................................................................................................................................6 4.2 Currents .................................................................................................................................8 4.3 Water Levels..........................................................................................................................9 4.4 Winds...................................................................................................................................11 5 Study Approach Methodology...................................................................................................12 5.1 Water Levels........................................................................................................................12 5.2 Local Sea.............................................................................................................................13 5.3 Joint Occurrence..................................................................................................................13 5.4 Wave Set-up/Run-up ...........................................................................................................14 5.5 Inland Attenuation................................................................................................................14 5.6 Mean Sea Level Rise...........................................................................................................15 5.7 Freeboard ............................................................................................................................15 5.8 Average Recurrence Interval...............................................................................................16 5.9 Discussion............................................................................................................................17 6 Data...............................................................................................................................................18 6.1 LMC Information ..................................................................................................................18 6.2 Meteorological Data.............................................................................................................18 6.3 Water Level Data .................................................................................................................19 6.4 Wave Data ...........................................................................................................................22 6.5 Discharge and Current Data................................................................................................22 6.6 Bathymetric Data .................................................................................................................22 7 Numerical Model Development..................................................................................................23 7.1 Hydrodynamic Wind Set up Model ......................................................................................23 7.1.1 Hydrodynamic Numerical Scheme..................................................................................23 7.1.2 Model Setup ....................................................................................................................24 1 April 2010 Cardno Lawson Treloar Pty Ltd iii H:\Doc\2010\Reports.2010\Rep2358v5.Doc Estuarine Planning Levels Study – Foreshore Region of Leichhardt Local Government Area Prepared for Leichhardt Municipal Council 7.2 Numerical Wave Model........................................................................................................26 7.2.1 SWAN Model Calibration.................................................................................................27 8 Numerical Model Results ...........................................................................................................28 8.1 Wind Set-Up.........................................................................................................................28 8.2 Local Sea Waves.................................................................................................................28 8.3 Swell Waves ........................................................................................................................28 9 Design Planning Levels..............................................................................................................29 9.1 Storm Tide Level..................................................................................................................29 9.2 Local Wind Set-up ...............................................................................................................29 9.3 Wave Set-up ........................................................................................................................29 9.4 Local Design Wave..............................................................................................................29 9.5 Wave Run-up.......................................................................................................................30 9.5.1 Wave Run-up with No Overtopping.................................................................................30 9.5.2 Wave Run-up with Overtopping ......................................................................................31 9.5.3 Overtopping when SWL is above the Crest ....................................................................31 9.6 Estuarine Planning Levels ...................................................................................................31 9.6.1 Foreshore Finishes..........................................................................................................32 9.6.2 Inland Reduction in Estuarine Planning Levels...............................................................32 9.6.3 Further Considerations....................................................................................................32 9.7 Application of the Estuarine Planning Level ........................................................................33 10 Concluding Remarks ..............................................................................................................34 11 References ...............................................................................................................................35 List of Tables Table 5.1 Risk Levels Associated with the 100-Years ARI...................................................................16 Table 6.1 Wind Speeds (m/s) by Octant ...............................................................................................19 Table 6.2 Wind Speeds (m/s) at Selected ARI - 10 minute Average Speeds ......................................19 Table 6.3 Tidal Planes for Port Jackson - Fort Denison .......................................................................20 Table 6.4 Extreme Water Levels in Port Jackson – Fort Denison ........................................................20 Table 9.1 Surface Roughness Reduction Factors ................................................................................32 1 April 2010 Cardno Lawson Treloar Pty Ltd iv H:\Doc\2010\Reports.2010\Rep2358v5.Doc Estuarine Planning Levels Study – Foreshore Region of Leichhardt Local Government Area Prepared for Leichhardt