City of Cockburn Coastal Adaptation Plan Presentation to the CLIMATE CHANGE IN THE SWAN REGION Forum, Wembley Golf Course, Wednesday 16 th November 2016 by Doug Vickery, Manager Infrastructure Services, City of Cockburn
CSCA Area of Interest Coastline from Fremantle South Mole to Point Peron & east coast of Garden Island
Background to CSCA Formation • High value Cockburn Sound & Owen Anchorage coastline - significant current and proposed development along the coast. • Consensus that climate change poses a threat through coastal inundation and erosion, but lack of knowledge regarding local specific vulnerability - require justifiable information for planning decisions. • Joint funded project brief February 2010. • MOU signed May 2011 – Agreement to: a) Build and share knowledge re coastal vulnerability to climate change; b) Assist in the development of strategies to address those vulnerabilities; and c) Enter into partnerships and agreements with other parties in pursuit of (a)&(b) • Chaired and administrative support by the City of Cockburn
State Government Stakeholders Other Stakeholders
The Project Cockburn Sound Coastal Vulnerability & Flexible Adaptation Pathways Project Stage 3 Preparation Phase Stage 1 Stage 4 Stage 2 (project brief & Flexible Adaptation Coastal Vulnerability Monitoring & Values & Risk stakeholders Plan Development Study Implementation Assessment identification) & Review Report Assessed current knowledge / data and Recommended: - Establish Physical - Sensitivity (Phase I) – What change can be anticipated to occur? Where? When? - Assess associated Vulnerability (Phase II) – What impacts can be expected to occur as a result of this change? Where? When? - Prioritise Response (Phase III) – What is the importance and urgency of dealing with the Jul’10-Apr’11 impacts? - Assign Adaptation Options and Actions (Phase IV) – How will the impacts be addressed at a range of temporal and spatial scales? – Whole-of-Sound and site specific. What? When? How Much? - Formulate an Adaptation Implementation Plan – How will the adaptation planning carried out in Phase IV be implemented? By Whom?
The Project Cockburn Sound Coastal Vulnerability & Flexible Adaptation Pathways Project Stage 3 Preparation Phase Stage 1 Stage 4 Stage 2 (project brief & Flexible Adaptation Coastal Vulnerability Monitoring & Values & Risk stakeholders Plan Development & Study Implementation Assessment identification) Review Report June’12- Mar’13
‘Stage 1’ - Vulnerability Report Outcomes Erosion Hazard – Areas at Risk Inundation Hazard – Projected Levels Existing acute erosion risk Garden Island north of Colpoys Point � Sea Sea Sea Sea Palm Beach, Rockingham Level Level Level Level � Storm Event Kwinana Bulk Terminal Present +0.5 m +0.9 m +1.5 m � Day SLR SLR SLR Most severe long-term erosion anticipated 1 year ARI 1.00 m 1.50 m 1.90 m 2.50 m North of Catherine Point, North Coogee � (63% AEP) AHD AHD AHD AHD Woodman Point areas � Kwinana Industrial Area to James Point 10 year ARI 1.16 m 1.66 m 2.06 m 2.66 m � (10% AEP) AHD AHD AHD AHD Increased erosion due to sea level rise anticipated South of Catherine Point groyne 100 year ARI 1.34 m 1.84 m 2.24 m 2.84 m � (1% AEP) AHD AHD AHD AHD James Point to Kwinana Industrial Area � South of Garden Island � 500 year ARI 1.48 m 1.98 m 2.38 m 2.98 m South Beach (0.2% AEP) AHD AHD AHD AHD � Naval Base �
Erosion & Inundation Hazard Mapping
The Project Cockburn Sound Coastal Vulnerability & Flexible Adaptation Pathways Project Stage 3 Preparation Phase Stage 1 Stage 4 Stage 2 (project brief & Flexible Adaptation Coastal Vulnerability Monitoring & Values & Risk stakeholders Plan Development & Study Implementation Assessment identification) Review Report Dec’12- Jun’14
Cockburn Sound Coastal Vulnerability & Flexible Adaptation Pathways Project Preparation Phase Stage 3: Flexible (project brief & Stage 1: Coastal Stage 2: Values & Risk Adaptation Plan Stage 4: Monitoring & stakeholders Vulnerability Study Assessment Development & Review Implementation identification) Report Stage 2 - Values & Risk Assessment 2013/14 • Identified the coastal assets within the areas potentially affected by the coastal erosion or inundation. • Estimated the ‘value at risk’ of these assets based on economic, social/cultural and ecosystem service factors. • Undertook a risk assessment of the identified threats for timeframes out to year 2110. • Provided ‘First pass’ suggested adaptation options and for each vulnerable section of coast based on Avoid / Accommodate / Protect / Protect & Intensify / Retreat. • Consultation with Stakeholders other than community.
The Project Cockburn Sound Coastal Vulnerability & Flexible Adaptation Pathways Project Stage 3 Preparation Phase Stage 1 Stage 4 Stage 2 (project brief & Flexible Adaptation Coastal Vulnerability Monitoring & Values & Risk stakeholders Plan Development & Study Implementation Assessment identification) Review Report Jul’14 – Nov’16
Cockburn Sound Coastal Vulnerability & Flexible Adaptation Pathways Project Preparation Phase Stage 3: Flexible (project brief & Stage 1: Coastal Stage 2: Values & Risk Adaptation Plan Stage 4: Monitoring & stakeholders Vulnerability Study Assessment Development & Review Implementation identification) Report ‘Stage 3’ – Report & Coastal Adaptation Plans – Stages: • Stakeholder & Community consultation • Compendium of Adaptation options • Adaptation Plan Report and a Coastal Adaptation Plan for each LGA Principles : - Making the right adaptation decision to suit current values and circumstances without impeding future decision making; - Adaptation planning should reflect social, environmental and economic values of the coast; - Any coastal protection work option should be evaluated based on full life cycle benefits, costs and impacts.
DECISION POINT (TRIGGER 1) DEVELOPMENT IN VULNERABLE COASTAL AREA RELOCATE LAND USE AND ASSETS OUTSIDE COASTAL RISK AREAS AVOID & PLANNED RETREAT - STRATEGIC PLANNING TO LOCATE AND Decision Triggers Adaptation Response DECISION POINT (TRIGGER 2) DECISION POINT (TRIGGER 3) LONG TERM (100 YEAR) PLANNING HORIZON DECISION POINT (TRIGGER 3) DECISION POINT (TRIGGER 4) INTOLERABLE RISK ZONE TOLERABLE RISK ZONE
Decision Triggers Stage 3 Cockburn Sound Coastal Adaptation Plan
Coastal Management Unit Coastal Vulnerabilities Immediate Planning Horizon (to Long-term Planning Horizon (to 2030) 2110) CMU 3 – North Coogee Erosion, with intolerable risk presented to Interim protection using hard- Continued interim protection (using assets and a loss of beach area in the passive engineering measures in the hard-passive engineering measures City of immediate planning horizon for some areas, form of groynes of offshore such as groynes or offshore increasing in the lead up to 2070. breakwaters breakwaters) may be feasible Cockburn – CMU 4 – Port Coogee Inundation, with intolerable risk presented to Avoid Interim protection (using hard-active some assets and a loss of beach area leading up engineering measures) may be feasible Key Accommodate to 2110. CMU 5 – Coogee Beach Erosion, with intolerable risk presented to Avoid Avoid Adaptation assets and a loss of beach area leading up to Accommodate Accommodate 2040 Retreat Measures CMU 6 – Woodman Point Erosion and inundation, with intolerable risk Avoid Avoid Reserve presented to some conservation assets in the Accommodate Accommodate immediate planning horizon. Retreat Retreat CMU 7 – Woodman Point Erosion and inundation, with intolerable risk Avoid Avoid presented to some conservation assets in the Accommodate Accommodate immediate planning horizon. Retreat Retreat CMU 8 – Australian Marine Adequately prepared for inundation and Do nothing Do nothing Complex erosion events in the short to medium term Monitor Monitor (up to 2070) CMU 9 – Henderson South Not vulnerable to coastal actions Do nothing Do nothing Monitor Monitor
City of Cockburn – Key Adaptation Measures - CMU 3 North Coogee
CMU 5 – Coogee Beach CMU 4 – Port Coogee
CMU 6 – Woodman Point Reserve CMU 7 – Woodman Point
Stage 3 – Conclusions & Recommendations – LGA’s • Incorporate coastal adaptation planning into the LGA’s Strategic Community Plans - to provide a local governance framework for integrated decision making in relation to strategic land use, infrastructure and capital works planning. • The LG’s Local Planning Strategies and Schemes be amended to include the establishment of Special Control Areas (SCA’s) for the land identified at risk in the period out to 2110 - establishing a long-term intention to retreat in these areas and providing special planning instruments.
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