Ex-HMAS Adelaide Artificial Reef Review of Environmental Factors 301017-00077 2-Dec-09 Infrastructure and Environment 8-14 Telford Street Newcastle East NSW 2300 Australia Tel: +61 2 4907 5300 Fax: +61 2 4907 5333 www.worleyparsons.com WorleyParsons Services Pty Ltd ABN 61 001 279 812 © Copyright 2009 WorleyParsons Services Pty Ltd LAND AND PROPERTY MANAGEMENT AUTHORITY EX-HMAS ADELAIDE ARTIFICIAL REEF REVIEW OF ENVIRONMENTAL FACTORS SUMMARY This Review of Environmental Factors (REF) has been prepared to address the scuttling of the Ex- HMAS ADELAIDE as an artificial reef and its use as a recreational dive site. A number of management and monitoring plans would be implemented to mitigate potential impacts during the scuttling operation; manage access to the dive site; and assess the long term impacts of the vessel on the immediate marine environment. The scuttling process may have minor, temporary impacts such as discolouration of water due to suspension of sediments and mixing of freshwater, seawater and air; minor fish kills due to cutting charges employed during scuttling or collision with the vessel as it sinks; exclusion of boats within approximately 1km of the vessel during preparation for, scuttling and post scuttling activities; and congestion and altered traffic and parking arrangements during the scuttling event. Benthic organisms within the ‘footprint’ of the scuttled vessel may be smothered and a sandy habitat would be replaced with an artificial ‘reef’ habitat. Considering the extent of sandy habitat in the general area this permanent loss of sandy habitat is not considered significant. Over time the impact of the artificial reef is expected to be positive, providing habitat for a variety of marine species (possibly including threatened species) and increasing the diversity and abundance of marine life at the site. The Ex-HMAS ADELAIDE is expected to provide a ‘world-class’ diving experience and would complement other dive opportunities in the Terrigal/ Avoca area. Flow-on benefits to the Central Coast economy are expected. Disclaimer This report has been prepared on behalf of and for the exclusive use of the Land and Property Management Authority, and is subject to and issued in accordance with the agreement between the Land and Property Management Authority and WorleyParsons Services Pty Ltd. WorleyParsons Services Pty Ltd accepts no liability or responsibility whatsoever for it in respect of any use of or reliance upon this report by any third party. Copying this report without the permission of the Land and Property Management Authority and WorleyParsons Services Pty Ltd is not permitted. PROJECT 301017-00077 - EX-HMAS ADELAIDE ARTIFICIAL REEF REV DESCRIPTION ORIG REVIEW WORLEY- DATE CLIENT DATE PARSONS APPROVAL APPROVAL A Issued for internal & client H Nelson N/A 17-Nov-09 N/A review B Final H Nelson Client 2-Dec-09 N/A D Messiter i LAND AND PROPERTY MANAGEMENT AUTHORITY EX-HMAS ADELAIDE ARTIFICIAL REEF REVIEW OF ENVIRONMENTAL FACTORS CONTENTS 1. INTRODUCTION ................................................................................................................7 1.1 Background.........................................................................................................................7 1.2 Preliminary Site Selection...................................................................................................9 1.3 Associated Documents .....................................................................................................11 1.3.1 Scuttling Management Plan .................................................................................12 1.3.2 Long Term Management Plan .............................................................................12 1.3.3 Asset Management Plan......................................................................................12 1.3.4 Ex-HMAS ADELAIDE Reserve Plan of Management..........................................13 1.3.5 Updated Terrigal Haven Plan of Management ....................................................13 1.4 Objectives .........................................................................................................................14 2. ENVIRONMENTAL ASSESSMENT FRAMEWORK ........................................................16 2.1 Environmental Planning and Assessment Act..................................................................16 2.2 Other Relevant Environmental Legislation and Plans ......................................................16 3. CONSULTATION..............................................................................................................19 3.1 Interagency Steering Committee ......................................................................................19 3.2 2007/2008 Stakeholder Meetings.....................................................................................20 3.3 Consultation for this REF..................................................................................................20 4. DESCRIPTION OF THE ACTIVITY..................................................................................22 4.1 Original Ship Details .........................................................................................................22 4.2 Ship Preparation ...............................................................................................................23 4.2.1 Ship Clean-up ......................................................................................................23 4.2.2 Dive Design..........................................................................................................24 4.3 Ship Placement.................................................................................................................25 4.3.1 Location, Orientation and Depth ..........................................................................25 4.3.2 Towing and Scuttling Method...............................................................................27 4.3.3 Spectator Management........................................................................................28 4.4 Completed Reef ................................................................................................................28 ii EX-HMAS ADELAIDE ARTIFICIAL REEF REVIEW OF ENVIRONMENTAL FACTORS 4.4.1 Exclusion Zone.....................................................................................................28 4.4.2 Access, Moorings, Dive Routes and Down Time.................................................29 4.4.3 Management ........................................................................................................32 4.4.4 Monitoring and Risk Management .......................................................................33 4.4.5 Maintenance.........................................................................................................34 5. DESCRIPTION OF THE EXISTING ENVIRONMENT .....................................................35 5.1 Water Levels .....................................................................................................................35 5.2 Physical Characteristics of the Seabed ............................................................................35 5.3 Sediment Characteristics..................................................................................................36 5.4 Water Quality and Clarity..................................................................................................40 5.5 Ocean and Coastal Currents ............................................................................................41 5.6 Coastal Storms and Wave Climate...................................................................................42 5.7 Marine Ecology .................................................................................................................46 5.7.1 Benthic Habitats...................................................................................................46 5.7.2 Pelagic Environment ............................................................................................47 5.7.3 Fish ......................................................................................................................47 5.8 Recreation and Tourism ...................................................................................................54 5.8.1 Visitation and Dive Tourism .................................................................................54 5.8.2 Water-based Facilities and Uses .........................................................................57 5.8.3 Adjoining Shore-based Facilities and Uses .........................................................57 5.9 Maritime Archaeology .......................................................................................................58 6. ASSESSMENT OF THE LIKELY ENVIRONMENTAL IMPACTS ....................................60 6.1 Ship Scuttling Operation ...................................................................................................60 6.1.1 Optimal Scuttling Season.....................................................................................60 6.1.2 Navigation ............................................................................................................60 6.1.3 Noise and Vibration..............................................................................................60 6.1.4 Air Quality.............................................................................................................61