Coastal Hazards and Climate Change GUIDANCE FOR LOCAL GOVERNMENT Lead authors R Bell (National Institute of Water and Atmospheric Research (NIWA)) J Lawrence (PS Consulting Ltd, and New Zealand Climate Change Research Institute, Victoria University of Wellington) S Allan (Allan Planning and Research Ltd) P Blackett (NIWA) S Stephens (NIWA) Contributing authors and advisers J Hannah (Vision New Zealand Ltd), T Shand (Tonkin+Taylor), P Thomson (Statistics Research Associates Ltd), B Glavovic (School of People, Environment and Planning, Massey University), R Britton (Planning Consultant, Focus Management Group), M Dickson (School of Environment, University of Auckland), P Quilter (Tonkin+Taylor), N Hudson and K Davies (NIWA) Cover photo supplied by Dave Allen, NIWA. Disclaimer The information in this publication is, according to the Ministry for the Environment’s best efforts, accurate at the time of publication. 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Published in December 2017 by the Ministry for the Environment Manatū Mō Te Taiao PO Box 10362, Wellington 6143, New Zealand ISBN: 978-1-98-852535-8 Publication number: ME 1341 © Crown copyright New Zealand 2017 This document is available on the Ministry for the Environment’s website: www.mfe.govt.nz. Contents About this guidance 11 Section A: What is happening? 16 1 Setting the context and preparation 17 1.1 Compounding coastal hazard risk 17 1.2 Why we need to adapt in coastal areas 20 1.3 Planning and risk management context 20 1.4 Preparation for adaptation to coastal climate change 24 2 Role of local government 27 2.1 Responsibilities devolved to the appropriate level 28 2.2 Leadership in the local context 30 2.3 New Zealand Coastal Policy Statement 2010 31 2.4 Other principles for local government 35 2.5 Adapting to climate change and adaptive pathways 41 3 Community engagement principles 44 3.1 What is a community or stakeholder? 45 3.2 Why engage with the community? 46 3.3 Spectrum of public participation – where to position the engagement 50 3.4 Guiding principles for inclusive engagement processes 55 3.5 Designing an engagement strategy in practice 59 3.6 Navigating engagement in this guidance 62 4 Understanding and awareness of changing coastal risk 63 4.1 Conceptual basis for this guidance 63 4.2 Why is it important to include uncertainties in adaptation planning? 66 4.3 Analysing, characterising and dealing with uncertainty 67 4.4 Why can decisions not wait until uncertainties are resolved? 69 4.5 Risk transfer 71 4.6 Summary 72 5 Changing climate and future projections for coastal areas 73 5.1 Certainty of climate change so far 73 5.2 Observations and trends for sea-level rise (global and New Zealand) 74 5.3 Vertical land movement in New Zealand – adjustments for local sea-level rise 82 5.4 Climate change scenarios and context for sea-level rise projections 86 5.5 Global climate change projections and commitment to sea-level rise 92 5.6 Basis for sea-level rise guidance for New Zealand 99 5.7 Specific sea-level rise guidance for planning and design in New Zealand 103 5.8 Climate change effects on storms, winds, storm tides and waves 112 5.9 Guidance: storm surges, waves and winds 114 Coastal hazards and climate change: Guidance for local government 3 6 Coastal hazards: impacts and assessments 116 6.1 Introduction 116 6.2 Coastal hazard sources 118 6.3 Coastal geomorphology 120 6.4 Climate change impacts 121 6.5 A guide to coastal hazard assessment 134 6.6 Coastal hazard assessment examples and case studies 152 Section B: What matters most? 163 7 Establishing values and objectives 164 7.1 Break the ground 164 7.2 Who should participate? 165 7.3 What are the community values? 166 7.4 Reframing community values as objectives 171 7.5 Local government objectives 172 7.6 Collation of community and local government objectives 172 8 Vulnerability and risk 173 8.1 Vulnerability assessment 174 8.2 Risk assessment 178 8.3 Engagement for assessing vulnerability and risk 183 Section C: What can we do about it? 186 9 Adapting to changing coastal risks arising from climate change impacts 187 9.1 Introduction 188 9.2 Adaptation decision-making 193 9.3 Identify options and pathways (step 5) 194 9.4 Options and pathways evaluation (step 6) 200 9.5 Community engagement 207 Section D: How can we implement the strategy? 209 10 Adaptive planning strategy and implementation 210 10.1 Adaptive planning strategy 210 10.2 Adapting to increasing coastal hazard risk through planning 217 Section E: How is it working? 237 11 Monitoring and reviewing 238 11.1 Context for monitoring and review 239 11.2 What to monitor? 240 11.3 Involving communities in monitoring 243 11.4 Reviewing plans and adaptation pathways 244 4 Coastal hazards and climate change: Guidance for local government 12 Tools and resources 246 12.1 Resources 246 12.2 Tools and simulation games 247 Glossary of abbreviations and terms 248 References 256 Coastal hazards and climate change: Guidance for local government 5 Tables Table 1: Questions underpinning the different methods used to identify stakeholders 47 Table 2: Questions underpinning different methods to understand the current social context 48 Table 3: Facilitating community and stakeholder inclusion in the decision-making process 49 Table 4: Key questions when exploring the type of engagement process to undertake – based on purpose, knowledge and complexity 53 Table 5: Key questions when exploring the type of engagement process to undertake – based on values and trust 54 Table 6: Key questions when exploring the engagement process to undertake – based on impacts and distribution 54 Table 7: Updated long-term mean sea level trends at the four main ports, for the entire record and split before and after 1961 81 Table 8: Summary of approaches to deriving future sea-level rise projections 91 Table 9: Projected global mean sea level rise to 2100 for RCP4.5 and RCP8.5 scenarios, comparing three sets of projections 96 Table 10: Decadal increments for projections of sea-level rise (metres above 1986– 2005 baseline) for the wider New Zealand region (for the four future scenarios from figure 27) 106 Table 11: Approximate years, from possible earliest to latest, when specific sea-level rise increments (metres above 1986–2005 baseline) could be reached for various projection scenarios of sea-level rise for the wider New Zealand region 107 Table 12: Minimum transitional New Zealand-wide SLR allowances and scenarios for use in planning instruments where a single value is required at local/district scale while in transition towards adaptive pathways planning using the New Zealand-wide SLR scenarios 108 Table 13: Example sources and actual or potential effects for different coastal hazards 122 Table 14: Examples of location and level of uncertainty applied to components of a coastal hazard assessment 141 Table 15: Environmental data types and their potential use in coastal hazard assessment 149 Table 16: Four categories of methods that can be applied to gain an understanding of community values 167 Table 17: Two examples of translating values into objectives 171 Table 18: Key questions to address when generating local government objectives 172 Table 19: Common challenges and potential responses to differences or conflicts of values and interest 183 6 Coastal hazards and climate change: Guidance for local government Table 20: Common statements and characteristics of methods to respond to issues of urgency and differences in risk perception 184 Table 21: Common statements and characteristics of methods to respond to distrust or questioning of scientific data and method 184 Table 22: Common statements and characteristics of methods to respond to uncertain futures and social change 185 Table 23: Applicability of different decision support tools 202 Table 24: Approaches for including community interests in options and pathways identification 208 Table 25: Types of plan and planning processes available to local government to help in managing coastal hazard risks 224 Table 26: Planning methods and techniques available to local government to help in managing coastal hazard risks 229 Table 27: Coastal protection options 233 Table 28: Opportunities to include the community, iwi/hapū and stakeholders in monitoring 244 Figures Figure 1: The 10-step decision cycle, grouped around five questions 14 Figure 2: Step 1 in the 10-step decision cycle: What is happening? – preparation and context 17 Figure 3: