Managed Retreat from Coastal Hazards: Options for Implementation

Abstract
Table of contents

Report: TR 2006/48
Author: Christopher Turbott, Andrew Stewart

Abstract

There are substantial areas of existing development at risk from coastal hazards in the Auckland, Waikato and Bay of Plenty regions.

Communities have two basic alternative choices for management of the hazard. These are to:

adopt a strategy of holding the line of the shore, which involves management of natural coastal processes, or
adopt a strategy of retreat from the hazard, which involves managing development.

Holding the line of the shore has been the generally preferred approach over at least the last century. However, it is increasingly questioned because of the high ongoing cost, the adverse effects of protection works on beach systems, and the uncertain feasibility of maintaining protection works over large areas of retreating shoreline in the long-term. Consequently, the second strategy of retreat is receiving increasing attention with an emphasis on a managed process of retreat; i.e. “managed retreat”.

However, managed retreat is not well understood in the New Zealand context. This report characterises managed retreat and reviews the main options available for implementation.

The report found that managed retreat would need to be implemented as a long-term strategy. It may take several generations for it to become accepted as a normal response to coastal hazards. Councils would need to comprehensively integrate managed retreat strategies into long-term urban growth, infrastructure and reserves planning, as well as regulatory planning.

Note: Partial funding and support was provided by: the Auckland Regional Council, Environment Bay of Plenty and the Thames Coromandel District Council

Managed Retreat from Coastal Hazards: Options for Implementation
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	Foreword	1
	Executive Summary	2
1	Introduction	4
1.1	Objectives	4
2	Managed retreat concepts	4
3	Decision making and management of coastal hazards	6
4	Statutory requirements	6
4.1	Local Government Act 2002	6
4.2	Resource Management Act 1991	7
4.3	New Zealand Coastal Policy Statement	8
5	Coastal Hazard Risk	9
5.1	How risk from coastal hazard arises and what is at-risk	9
5.2	The current state of coastal hazard risk	10
5.2.1	Waikato Region	10
5.2.2	Bay of Plenty	10
5.2.3	Auckland Region	11
5.2.4	Tsunami risk	11
5.3	Property values and risk	11
5.3.1	Coastal property values	11
5.3.2	Property values and risk	12
5.4	Insurance and risk spreading	14
5.5	The social, economic and political context	14
5.6	Circumstances where retreat could occur	16
5.7	Historical examples of retreat	16
5.7.1	Mokau Spit, Waitomo	16
5.7.2	Muriwai Beach, Auckland	17
5.7.3	Ohiwa Spit, Bay of Plenty	17
5.7.4	Pourewa Point, Aotea Harbour	18
5.7.5	Te Kopi, Wairarapa	18
5.7.6	Waihi Beach, Bay of Plenty	18
5.7.7	Wainui Beach, Gisborne District	19
5.8	Managed Retreat and Local or Central Government Intervention	19
5.9	Scale of retreat	20
5.9.1	Micro-retreat	20
5.9.2	Relocation within a property	21
5.9.3	Relocation to other sites	21
5.9.4	Large-scale relocation of settlements	21
6	Methods of Implementing Managed Retreat	22
6.1	Provision of Information	22
6.2	Regulation	23
6.2.1	District Plan Rules	23
6.2.2	Regional rules	25
6.2.3	Central Government legislation and regulation.	25
6.2.4	Covenants	26
6.3	Financial instruments	26
6.3.1	Purchase of property	26
6.3.2	Subsidies for relocation	26
6.3.3	Taxation of risk or adverse effects.	26
6.3.4	Pre-paid relocation fund.	26
6.3.5	Transferable development right	28
6.4	Public infrastructure	28
6.4.1	Effect of existing infrastructure on retreat feasibility	28
6.4.2	Shorefront Road with residential development landward of the road	28
6.4.3	Shorefront residential development with road access from the rear	30
6.4.4	Shorefront development with access roads perpendicular to the shore	30
6.4.5	Public reserves	31
6.4.6	Future provision of infrastructure and the location and form of development.	34
7	Options for Managed Retreat	35
7.1	Selecting an option	35
7.2	Option 1: Relocation within existing properties	36
7.2.1	Summary	36
7.2.2	Descriptions	36
7.2.3	What form of intervention is required	37
7.2.4	Who Needs to be involved	37
7.2.5	Risk outcomes	38
7.2.6	Barriers	38
7.2.7	Favourable conditions	39
7.3	Option 2: Change property rights to public ownership	39
7.3.1	Summary	39
7.3.2	Description	40
7.3.3	What form of intervention is required	40
7.3.4	Who needs to be involved	40
7.3.5	Risk outcomes	40
7.3.6	Barriers	41
7.3.7	Favourable conditions	43
7.4	Option 3: Change use rights to a fixed term of use	43
7.4.1	Summary	43
7.4.2	Descriptions	44
7.4.3	Form of intervention required	47
7.4.4	Who needs to be involved	47
7.4.5	Risk outcomes	48
7.4.6	Barriers	49
7.4.7	Favourable conditions	52
8	Staging Retreat	52
8.1	Retreat from episodic erosion events.	53
8.2	Situations with existing protection works	54
8.3	Managing retreat of protection works	55
8.4	Long-term retreat	56
9	Summary	56
9.1	Coastal hazard risk and perceptions	56
9.2	The acceptability of retreat	57
9.3	New Zealand examples	57
9.3	Overseas Examples	57
9.5	Options for implementing retreat	58
9.5.1	Non-regulatory options	58
9.5.2	Regulatory options	59
9.6	Infrastructure and reserves	61
9.7	Long-term implications	61
10	Conclusions and Further Research	62
10.1	Extent of risk and long-term management	62
10.2	Socioeconomic factors	63
10.3	Methods for implementing retreat	64
10.3.1	Information	64
10.3.2	Relocation	64
10.3.3	Regulation	65
10.3.4	Property rights	65
10.4	Compensation issues	67
Appendix I:	Shaw Rd Waihi Beach Values	68
Appendix II:	Wainui Beach Protection Works	70
Appendix III:	Further Evaluation of Relocation	72
Appendix IV:	Standard Conditions for Development in the Western Bay of Plenty	77
Appendix V:	A Hypothetical Infrastructure and Development Layout to Facilitate Retreat Over Time.	78
Appendix VI:	Alternative Relocation Scenarios	83
Appendix VII:	Transferable Development Rights	84
	References	88

Managed Retreat from Coastal Hazards: Options for Implementation

Abstract

Table of contents