Stockton Beach Coastal Processes Study Final Report Stage 1- Sediment Transport Analysis and Description of On-going Processes Newcastle City Council December 2006 Stockton Beach Coastal Processes Suite 204, 781 Pacific Highway Chatswood NSW 2067, Study Australia Tel: +61 (2) 8440 5700 Fax: +61 (2) 8440 5701 Final Report e-mail: [email protected] Stage 1 - Sediment Transport Analysis and Web: www.dhigroup.com Description of On-going Processes December 2006 Client Client’s representative Newcastle City Council Mr John Simpson Project Project No Stockton Beach Coastal Processes Study 50258 Sediment Transport Analysis and Description of On- going Processes. Authors Date Juan Savioli 27 February 2007 Approved by 0 Technical Report JCS GPS GPS 27.02.07 Revision Description By Checked Approved Date Key words Classification Sediment Transport Open Sediment Transport Modelling Littoral Transport Internal Short, Medium and Long-Term Erosion Coastal Hazard Lines Proprietary Distribution No of copies Newcastle City Council: Mr John Simpson 2 + PDF DHI: JCS – DHI Office 1 C:\Documents and Settings\mwb\My Documents\Jobs\50258 - Stockton Phase 1\CD DHI Water & Environment Burn\Master\report\50258_Final_Rev13.doc3 © DHI Water and Environment Pty Ltd 2007 The information contained in this document produced by DHI Water and Environment Pty Ltd is solely for the use of the Client identified on the cover sheet for the purpose for which it has been prepared and DHI Water and Environment Pty Ltd undertakes no duty to or accepts any responsibility to any third party who may rely upon this document. All rights reserved. No section or element of this document may be removed from this document, reproduced, electronically stored or transmitted in any form without the written permission of DHI Water and Environment Pty Ltd. C:\Documents and Settings\mwb\My Documents\Jobs\50258 - Stockton Phase 1\CD DHI Water & Environment Burn\Master\report\50258_Final_Rev13.doc3 CONTENTS 1 EXECUTIVE SUMMARY ................................................................................................ 4 1.1 Background information.................................................................................................. 4 1.2 Objectives of the Study................................................................................................... 5 1.3 Scope of work and study approach ................................................................................ 5 1.4 Stage I – Main Findings .................................................................................................. 5 1.4.1 Short Term Processes .................................................................................................... 5 1.4.2 Medium and Long- Term Processes............................................................................... 6 1.5 Greenhouse Effects........................................................................................................ 8 2 INTRODUCTION .......................................................................................................... 10 2.1 Background................................................................................................................... 10 2.2 Objectives of the Study................................................................................................. 13 2.3 Scope of work and study approach .............................................................................. 14 2.3.1 Stage 1 - Process study. Determination of the on-going trends of the coastal processes at Stockton Beach......................................................................................................... 14 2.3.2 Stage 2 - Management study........................................................................................ 15 2.3.3 Stage 3 - Newcastle Coastline Management Plan Revision......................................... 15 3 DATA COLLECTION AND ANALYSIS ......................................................................... 17 3.1 Motivation ..................................................................................................................... 17 3.2 Water Level, Wave and Current Measurements at Stockton Beach Nearshore Area .. 17 3.2.1 Water Levels................................................................................................................. 18 3.2.2 Waves........................................................................................................................... 18 3.2.3 Current Measurements ................................................................................................. 19 3.3 Flow and velocity measurements at the Hunter River Entrance................................... 25 3.4 Wind Data..................................................................................................................... 29 3.5 Offshore Wave climate................................................................................................. 30 3.5.1 Offshore Wave Data..................................................................................................... 30 3.5.2 Yearly wave Roses ....................................................................................................... 34 4 WAVE TRANSFORMATION ........................................................................................ 38 4.1 Motivation ..................................................................................................................... 38 4.2 Regional Wave Modelling............................................................................................. 38 4.2.1 Model Setup.................................................................................................................. 40 4.2.2 Model Calibration.......................................................................................................... 42 4.2.3 Wave Model Results..................................................................................................... 46 4.3 Local Wave Modelling................................................................................................... 51 4.3.1 Wave Model Selection .................................................................................................. 52 4.3.2 PMS Model Setup......................................................................................................... 56 4.3.3 Model Comparisons...................................................................................................... 58 5 ESTABLISHMENT OF A 2D HYDRODYNAMIC MODEL............................................. 61 5.1 Motivation ..................................................................................................................... 61 5.2 Introduction ................................................................................................................... 61 5.3 Bathymetry.................................................................................................................... 61 5.4 Boundary Conditions .................................................................................................... 63 5.4.1 Ocean Boundary Conditions......................................................................................... 63 C:\Documents and Settings\mwb\My Documents\Jobs\50258 - Stockton Phase 1\CD i DHI Water & Environment Burn\Master\report\50258_Final_Rev13.doc3 5.4.2 River Boundary Condition............................................................................................. 64 5.5 General Model Specifications ....................................................................................... 66 5.6 Model Calibration.......................................................................................................... 66 5.7 Wave driven current comparisons ................................................................................ 75 6 HISTORICAL COASTLINE ANALYSIS ........................................................................ 76 6.1 Motivation ..................................................................................................................... 76 6.2 Definition of coastal processes ..................................................................................... 76 6.3 Previous coastal historical analysis .............................................................................. 77 6.3.1 1985 and 1995 Studies................................................................................................. 77 6.3.2 Newcastle Coastline Hazard Definition Study - WBM (1998) ....................................... 78 6.3.3 Shifting sands at Stockton Beach –Umwelt Pty Ltd - SMEC Pty Ltd (2002)................. 81 6.3.4 Newcastle Coastline Management Study - Umwelt Pty Ltd (2003) .............................. 84 6.4 Extended Coastal Analysis ........................................................................................... 84 6.4.1 Long and medium term................................................................................................. 85 6.4.2 Historical short-term events Analysis............................................................................ 96 6.5 Historical Dredging Activities at Newcastle Harbour................................................... 100 6.5.1 Dredging 1859-1961 ................................................................................................... 100 6.5.2 Dredging 1962 -1966 .................................................................................................