Coastal Climate Change Vulnerability and Flexible Adaptation Planning: the Cockburn Sound Coastal Alliance Experience

Transcription

1 Coastal Climate Change Vulnerability and Flexible Adaptation Planning: the Cockburn Sound Coastal Alliance Experience Presentation to Climate Change Forum by Doug Vickery Manager Infrastructure Services, City of Cockburn 21 September 2016

2 Presentation Contents The Place Cockburn Sound & Owen Anchorage The CSCA Formation and Participation The Coastal Vulnerability & Flexible Adaptation Pathways Project The Delivery Process Outcomes So Far Key Follow-up Actions & Lessons Learned

3 CSCA Area of Interest Coastline from Fremantle South Mole to Point Peron & east coast of Garden Island

4 RockinghamBeach CityofRockingham

5 Kwinana Beach - Industrial Strip City of Kwinana

6 Australian Marine Complex City of Cockburn

7 Woodman Point City of Cockburn

8 Port Coogee City of Cockburn Port Coogee Marina City of Cockburn

9 CY O Connor & South Beach Cities of Fremantle & Cockburn

10 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. Lack of knowledge amongst the Councils of Fremantle, Cockburn, Kwinana & Rockingham regarding local specific vulnerability. LG s and other Stakeholders require justifiable information for planning decisions. Agreement to form an Alliance.

11 Background cont February 2010 Agreement to jointly fund a Cockburn Sound Coastal Climate Change Study Brief (completed July 2010) April-May 2011 MOU for the CSCA finalised & signed, themes being to: 1. Build and share knowledge pertaining to the vulnerability of Cockburn Sound and Owen Anchorage coastal zone to the effects of climate change, including sea level rise; 2. Assist in the development of strategies to aid them in addressing the identified vulnerabilities; 3. Enter into partnerships and agreements with other parties in pursuit of the aims in (a) and (b) above.

12 State Government Stakeholders Other Stakeholders

13 The Project Cockburn Sound Coastal Vulnerability & Flexible Adaptation Pathways Project Preparation Phase (project brief & stakeholders identification) Stage 1 Coastal Vulnerability Study Stage 2 Values & Risk Assessment Stage 3 Flexible Adaptation Plan Development & Review Report Stage 4 Monitoring & Implementation

14 Cockburn Sound Coastal Vulnerability & Flexible Adaptation Pathways Project Preparation Phase (project brief & stakeholders identification) Stage 1: Coastal Vulnerability Study Stage 2: Values & Risk Assessment Stage 3: Flexible Adaptation Plan Development & Review Report Stage 4: Monitoring & Implementation

15 Cockburn Sound Coastal Vulnerability & Flexible Adaptation Pathways Project Preparation Phase (project brief & stakeholders identification) Stage 1: Coastal Vulnerability Study Stage 2: Values & Risk Assessment Stage 3: Flexible Adaptation Plan Development & Review Report Stage 4: Monitoring & Implementation Analyzed coastal processes to improve the understanding of existing coastal dynamics Assessed potential changes arising from climate change induced SLR of 0.5m (2070), 0.9m (2110) & 1.5m (2110+) and 1 yr, 10 yr, 100 yr & 500 yr ARI storm events Produced mapping of extent of potential erosion and inundation of vulnerable sections of the coastline based on the SLR & storm event scenarios.

16 Inundation Hazard Projected Levels Present Day +0.5 m SLR +0.9 m SLR +1.5 m SLR 1 year ARI (63% AEP) 1.00 m AHD 1.50 m AHD 1.90 m AHD 2.50 m AHD 10 year ARI (10% AEP) 1.16 m AHD 1.66 m AHD 2.06 m AHD 2.66 m AHD 100 year ARI (1% AEP) 1.34 m AHD 1.84 m AHD 2.24 m AHD 2.84 m AHD 500 year ARI (0.2% AEP) 1.48 m AHD 1.98 m AHD 2.38 m AHD 2.98 m AHD

17 Inundation Hazard Mapping 1 Year ARI Flood Event

18 Erosion & Inundation Hazard Mapping Friday, 28 February :5000 These Coastal Hazards Maps indicate coastal areas that may be susceptible to inundation, erosion and recession currently, or in the future as a result of ongoing sea-level rise and climate change, and should be used as a guide only. This indicative mapping is based on data that was available at the time of the assessment only. The Cockburn Sound Coastal Alliance and its member Local Government Authorities and agencies make no representations, warranties or undertakings about any of the information provided on these maps including, without limitation, their accuracy, their completeness or their quality or fitness for any particular purpose. Metadata: Erosion Scenarios, Event Inundation 1yr ARI, Event Inundation 10yr ARI, Event Inundation 100yr ARI, Event Inundation 500yr ARI

19 Erosion Hazard Areas at Risk Existing acute erosion risk Garden Island north of Colpoys Point Palm Beach, Rockingham Kwinana Bulk Terminal Most severe long-term erosion anticipated North of Catherine Point, North Coogee Woodman Point areas Kwinana Industrial Area to James Point Increased erosion due to sea level rise anticipated South of Catherine Point groyne James Point to Kwinana Industrial Area South of Garden Island South Beach Naval Base

20 Cockburn Sound Coastal Vulnerability & Flexible Adaptation Pathways Project Preparation Phase (project brief & stakeholders identification) Stage 1: Coastal Vulnerability Study Stage 2: Values & Risk Assessment Stage 3: Flexible Adaptation Plan Development & Review Report Stage 4: Monitoring & Implementation 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 taking account of likelihood and consequence of the identified threats for timeframes out to year Provided First pass proposed adaptation options for each vulnerable section of coast based on Avoid / Accommodate / Protect / Protect & Intensify / Retreat.

21 SPP 2.6 Hierarchy of Adaptation Options

22 Retreat Analysis of Adaptation Pathway Options Total net present value of these costs is $170 million No costs for adaptation works except the soft protection works for the Kwinana industrial area Significant costs to private landowners and community members The costs of removing remnants of assets and the decommissioning of sites in the Kwinana industrial area may be very high and beyond the total costs of the other pathways Maintain Total net present cost of $70 million Costs predominantly involve (soft) coastal adaptation works and the reconfiguration of infrastructure Reasonable loss of park, heritage and urban land to 2110 Beaches/beach amenity maintained although the character modified as a result of beach nourishment Intensify Total net present cost is $93 million Most significant costs are the adaptation works Recreation and urban beaches maintained although the character modified significantly artificial and narrow

23 Cockburn Sound Coastal Vulnerability & Flexible Adaptation Pathways Project Preparation Phase (project brief & stakeholders identification) Stage 1: Coastal Vulnerability Study Stage 2: Values & Risk Assessment Stage 3: Flexible Adaptation Plan Development & Review Report Stage 4: Monitoring & Implementation Stage 3 Report and a Coastal Adaptation Plan for each LGA The Study undertaken based on Principles of: - Making the right adaptation decision to suit current values and circumstances without impeding the ability of future generations to respond to increasing risk beyond the current timeframe; and - Adaptation planning should reflect social, environmental and economic values of the coast and any coastal protection work option should be evaluated based on full life cycle benefits, costs and impacts.

24 TOLERABLE RISK ZONE DECISION POINT (TRIGGER 1) DEVELOPMENT IN VULNERABLE COASTAL AREA 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 AVOID & PLANNED RETREAT - STRATEGIC PLANNING TO LOCATE AND RELOCATE LAND USE AND ASSETS OUTSIDE COASTAL RISK AREAS Stage 3 Cockburn Sound Coastal Adaptation Plan

25 Decision Triggers Stage 3 Cockburn Sound Coastal Adaptation Plan

26 Coastal Compartment Option Assessment

27 Stage 3 Conclusions & Recommendations Incorporation of coastal adaptation planning into the LGA s Strategic Community Plans will be necessary to provide a local governance framework for integrated decision making in relation to strategic land use, infrastructure and capital works planning.

28 Stage 3 Report Conclusions & Recommendations cont... State Gov t (WAPC) review of the Metropolitan Region Scheme (MRS) and other strategic land use plans for the coastal strip, to provide adaptation support framework and amendment where needed for land that will be affected in next 15 years; 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 establishing a long-term intention to retreat in these areas and providing special planning instruments. The LG s prepare Foreshore Management Plans for each area at risk, setting out the adaptation measures including the land use controls and any interim protection works proposed, for communicating with the community and stakeholders.

29 Stage 3 Conclusions & Recommendations cont Develop a firm plan for interim coastal protection works for those areas at risk in the current 15 year planning horizon and a provisional plan for protection works thereafter. Engage with the owners of assets in the SCA concerning plans for interim protection in the interim period and for development of longterm plans to retreat from the SCA in the lead up to triggers that require such action. Undertake or seek a study into the long term availability of suitable sand and rock to meet projected requirements for beach replenishment and coastal protection works (3m & 0.56m M3 resp). Ongoing monitoring of shoreline change and climate change SLR projections.

30 CSCA - Lessons Learned An alliance approach works - coastal processes and climate change risks don t stop at Council boundaries, shared resources mean bigger things can be achieved. A staged and iterative approach, refining as we go, has worked for us; Who s coast is it? it has fallen to Local Government to identify risks and inform our communities, but State and Federal Governments need to play a part. Leadership is needed to make it happen, officer level is where the work is done, but support from above is crucial.

31 Lessons Learned Current grant funding (in WA) is not suited to large multi stage projects spanning multiple years. Funding for planning is just as important (or more so) as for on-ground work or storm damage repair. Coastal assets at threat include beaches, natural and formed reserves, sites of significance they have social, cultural and ecosystem importance - but valuing them is not easy; Community engagement problematic to get the balance right just when, in what manner and with whom will ensure success? It s a long haul journey, building and retaining knowledge, experience and commitment in each Local Government will be a key success factor.

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33 Questions Doug Vickery Manager Infrastructure Services