9 Best practice

The section provides an overview of the provisions adopted by local authorities in New Zealand to address natural hazards in regional policy statements, regional and district plans, and best practice guidelines. It also comments on whether the approaches adopted are best practice and whether other mechanisms discussed in section 8 above could be adopted to ensure best practice.

9.1 The role of regional policy statements and regional and district plans

In order to identify the approaches to natural hazards in regional policy statements and regional and district plans to determine whether they represent best practice, this section firstly sets out the context of the role of regional policy statements and regional and district plans.

The responsibilities of territorial local authorities are discussed in section 8 of this report and include control over the use of land (including designations and heritage orders), subdivision, noise and hazard mitigation.

Regional policy statements and regional and district plans are located within a hierarchy of planning instruments under the RMA as described in Figure 6 below. While regional plans other than regional coastal plans are optional, territorial authorities are responsible for the mandatory preparation of district plans, which must now give effect to any national or regional policy statement (s75(3)). District plans must also not be inconsistent with any regional plan (s75(4)).

Figure 6. Hierarchy of planning instruments under the RMA

View full sized figure (including text description)

The matters to be considered in regional policy statements are given in s61 of the RMA, and the contents of regional policy statements are outlined in s62. The matters to be considered in regional and district plans are specified in s66 and s74 of the RMA respectively. The contents of regional and district plans are specified in s67 and s75 respectively. The process for preparing or changing a regional policy statement or regional or district plan is provided in s60, s65 and s73 and the First Schedule of the RMA.

Regional policy statements and regional and district plan development is undertaken within a cycle of public policy development including consideration of appropriate objectives, policies and methods.

What are the region / district's objectives?

An objective is a statement of what will be achieved when the issue is resolved, or the intended outcome (Ministry for the Environment, 2003a).

What are the region / district's policies?

Policies describe the position, consideration or criteria applied in deciding whether an activity or effects should be allowed. They guide the local authority on what will be allowed in any given circumstance.

"Policies describe how a particular objective is to be achieved. i.e. a course of action to be pursued to achieve certain environmental outcomes. A policy will thus need a specific programme of actions to carry it out."

(Policy Framework Guidance Note,www.qualityplanning.org.nz)

Policies in the district plan will outline how the objectives for natural hazard management included in the plan will be achieved.

What methods are appropriate?

A method is the way a policy is implemented (Ministry for the Environment, 2003a).

Section 32 of the RMA requires an evaluation of the objectives, policies and methods included in a regional policy statement or regional or district plan. This involves an assessment of the available options to ensure the most efficient and effective objectives, policies and methods are adopted in the policy statement or plan, and an evaluation of the costs and benefits of adopting the chosen options.

9.2 Approaches to natural hazards

The following section discusses the approaches to natural hazards adopted in a number of regional policy statements and regional and district plans, identified through research undertaken for this project.

The following format has been adopted to address these approaches:

- identification of the hazard

- outline of policy statement or plan approach and provisions - objectives, policies and methods (including rules)

- comment regarding whether best practice has been adopted

- identification of other mechanisms (as identified in Section 8 above) that could be adopted as best practice

9.2.1 Generic management / investigation of natural hazards

Our research shows that a number of policy statements and plans address natural hazards at a generic level.

Regional policy statements tend to provide generic statements on management of natural hazards. Some regional and district plans also have generic policies and objectives for natural hazard management, or ones that are applicable across all natural hazards rather than being specific to a hazard type.

Identification of hazard

Use and development in areas prone to natural hazards.

Policy statement or plan approach

Objectives

The following outcomes are sought in the objectives:

Improved knowledge of risk from natural hazards (Timaru District Plan); promotion of public awareness of the extent, character and consequences of natural hazards, enabling people to take appropriate actions (Invercargill City District Plan);
A pattern of human settlement that provides a high level of personal safety from natural hazards for its inhabitants; avoids or mitigates the risk to property and infrastructure from natural hazards; and does not accelerate or worsen the adverse effects of natural hazards upon the natural and physical environment (Gisborne Combined Regional Land and District Plan; Invercargill City District Plan);
The protection of natural features that could lessen the impact of natural hazards (Gisborne Combined Regional Land and District Plan);
Roles of authorities involved in management of natural hazards clearly identified and responsibilities consistently implemented (Waikato Regional Policy Statement).

Policies

The following ways of achieving the objectives have been identified:

Identify research needs for important natural hazards and undertake relevant investigations (Timaru District Plan);
Compile and publish Hazard Information Maps containing the best information known to Council on hazards - include areas of land susceptible to the effects of: riverine inundation; stormwater inundation; seismic activity; liquefaction; sea level rise/storm surge; coastal erosion; and wind (Invercargill City District Plan);
Advise / educate the public of known hazards (through Hazard Information Maps) (Invercargill City District Plan);
In extreme hazard areas where the natural hazard cannot be avoided or mitigated new development and any related subdivision should not occur; in all hazard prone areas, any new subdivision, use and development should avoid or minimise any risk of loss of life or injury or other environmental damage due to natural hazard (Gisborne Combined Regional Land and District Plan);
New subdivision, use and development, and significant infrastructure are located and designed to avoid significant natural hazards, unless there is a particular functional need to locate in an area subject to significant risk; new development within existing settlements which are at risk from natural hazards, shall not result in increased vulnerability, and should aim to reduce net vulnerability over time (Bay of Plenty Regional Policy Statement).
Take into account susceptibility to a natural hazard risk when considering any resource consent application (Ruapehu District Council);
Any assessment of a resource consent application within a hazard prone area shall consider the desirability of residential buildings being relocatable so they may be moved if the risk of damage becomes imminent (Gisborne Combined Regional Land and District Plan);
Patterns of human settlement, development and activities should not induce or accelerate the risk of natural hazards; when assessing an application for a resource consent the effects of that application on any hazard risk shall be considered (Gisborne Combined Regional Land and District Plan);
Integrity of natural systems and features that provide a defence against natural hazards should be recognised and protected - these include: the capacity of foredunes to act as natural protection against inundation and erosion; wetlands; and margins of estuaries (Gisborne Combined Regional Land and District Plan);
Recognise the limits of attempts to control natural processes by physical work and restrict such attempts to appropriate situations; mitigation works shall be designed and constructed in sympathy with the environment (Gisborne Combined Regional Land and District Plan);
A precautionary approach should be adopted where activities with unknown or little understood effects are proposed, or the effects on natural processes are difficult to assess (Gisborne Combined Regional Land and District Plan).

Methods

The following methods have been identified in plans to implement the policies:

Promote natural hazard awareness and avoidance / mitigation measures (Timaru District Plan);
Investigate the impact of natural hazards and methods to avoid / mitigate them; co-operate with any investigation and identification of the cost of avoiding or mitigating natural hazards (Timaru District Plan);
Carry out monitoring programmes to ensure the Council's knowledge of natural hazards and hazard management is kept up to date (Timaru District Plan);
Maintain and update hazard register (Timaru District Plan);
Collate hazard information in the Hazard Information Maps, and advise the public of information contained within the Maps pertaining to property (Invercargill City District Plan); areas subject to natural hazards will be included in Hazard Overlays on planning maps; restrictions applying to these Overlays will be included in the Plan (Gisborne Combined Regional Land and District Plan);
Zoning and general rules (Timaru District Plan).

Comment

The policy statements and plans reviewed as part of our research adopted an approach of identifying and mapping hazards, avoiding development in known hazard areas with high risks, and controlling activities in areas where hazard risks are less. While a generic approach may be suitable as an overall outline of natural hazard management objectives and policies, is not likely to be specific enough to avoid / mitigate natural hazards. Therefore, a hazard specific approach is likely to be most effective.

In our view, the Timaru and Invercargill District Councils provide good examples of best practice for the generic management / investigation of natural hazards, and their approaches are described above. The Gisborne Combined Regional Land and District Plan also provides some good approaches of best practice for generic management / investigation of natural hazards.

Overall we consider that there are enough best practice examples in the plans reviewed to develop model objectives, policies and methods applicable to all natural hazards for any best practice guide developed in the future.

Other mechanisms

The following other mechanisms may be used to assist with the management of natural hazards generally:

LIMs and PIMs to provide information on location and/or characteristics of known hazards
education programmes to improve knowledge and promote awareness and avoidance or mitigation measures
risk assessments and risk mitigation plans
advice and advocacy e.g. best practice guidelines
National Policy Statements
emergency management planning, including warning systems
lifeline engineering projects to assess vulnerability of lifelines and develop contingency and response plans

9.2.2 Coastal Hazards

As a result of New Zealand's extensive and varied coastline, a large number of urban settlements adjoin the coast - four out of five of New Zealand's major metropolitan areas are located (in part) in the coastal environment. In recent years there has been an increased pressure on coastal areas, with subdivision and development along the coastline having premium returns on investments.

Our research shows that coastal hazards are addressed in coastal strategies, regional coastal plans, and district plans, in response to these increasing pressures on the coast.

Identification of hazard

Coastal erosion and inundation from seawater are the two key natural hazards identified in plans.

Note that tsunami hazards are addressed separately in section 9.2.8.

Policy statement or plan approach

Objectives

The following outcomes are sought in the objectives:

Proactively reduce the level of risk on coastal communities from coastal hazards to an acceptable level (Wairoa Coastal Strategy); no increase in the total physical risk from coastal hazards (Bay of Plenty Regional Coastal Environment Plan);
Avoid, remedy or mitigate significant adverse effects on the environment as a result of measures used to manage coastal hazards (Regional Coastal Environment Plan for the Canterbury Region);
Avoid, remedy or mitigate damage or adverse effects to land, structures and the environment arising from coastal erosion and inundation (Tauranga District Plan);
Minimise the need for hazard protection works, and avoid or mitigate the actual or potential effects of coastal hazards by locating use and development away from areas which are subject to coastal erosion and sea water inundation (Regional Coastal Environment Plan for the Canterbury Region);
Recognise the importance of natural buffers as a means of protecting against the effects of natural hazards within the coastal environment (Wairoa Coastal Strategy);
Better understand coastal hazards in areas of the coastal environment where knowledge is limited, particularly where coastal hazards conflict with land-use or development (Wairoa Coastal Strategy).

Policies

The following ways of achieving the objectives have been identified:

Give priority to coastal hazard investigations and management in areas where there is a conflict between existing or proposed land use and hazards (Wairoa Coastal Strategy);
Identify, within the open coast, areas sensitive to coastal hazards (Bay of Plenty Regional Coastal Environment Plan);
Applications for new subdivision, use and development in areas sensitive to coastal hazard should be supported by a coastal hazards analysis (Bay of Plenty Regional Coastal Environment Plan);
Provide information to encourage people to avoid locating in hazard prone areas (Regional Coastal Environment Plan for the Canterbury Region);
Adopt a precautionary approach to new subdivision and development where there is insufficient hazard information to determine the level of risk (Wairoa Coastal Strategy);
Discourage new and further subdivision and development within areas identified as being subject to natural hazards (Wairoa Coastal Strategy);
Relocate, avoid further development and/or retreat lawfully established buildings and activities in the coastal hazard erosion policy area (Tauranga District Plan);
Subdivision shall not be undertaken on land wholly located with the current erosion risk zone (Tauranga District Plan);
New habitable buildings should be located away from areas of the coastal environment that are, or have the potential to be, subject to sea water inundation or coastal erosion (Regional Coastal Environment Plan for the Canterbury Region);
Subdivision within 50-year and 100-year Erosion Risk Zones will only be allowed where an alternative building site can be provided contiguous with and clear of the coastal hazard erosion policy area (Tauranga District Plan);
Subdivision, land use, building and development in the Coastal Protection Area is non-complying, so the natural coastal dune system and environment is retained in an undeveloped state and the effects of coastal erosion and inundation hazards on development are avoided (Tauranga District Plan);
Buildings on the rocky open coast outside of the identified areas sensitive to coastal hazards, should be located so as to avoid the hazard of cliff or slope instability, and storm surge and wave run up; A minimum new building platform height of 6 metres above mean high water mark is recommended (Bay of Plenty Regional Coastal Environment Plan);
Discourage residential development adjacent to river mouths or other areas potentially at risk from river mouth meandering (Bay of Plenty Regional Coastal Environment Plan);
Encourage the incorporation of coastal hazard zones into wider building set backs or reserves established to provide for recreation, natural character, or waahi tapu (Bay of Plenty Regional Coastal Environment Plan);
When exposed to risk from coastal erosion and inundation, buildings and activities within the coastal hazard erosion policy area shall be able to be practicably moved or relocated to an alternative building site beyond the coastal hazard erosion policy area and the foredune reinstated to maintain or enhance its natural buffering capacity (Tauranga District Plan);
Review to assess risk of erosion and inundation, where sand dunes recede near to a building or activity, which may result in requirement for building / activity to be practicably moved to an alternative building site (Tauranga District Plan).
Avoid or mitigate effects of new subdivision or use on the current active foredune areas; protection of active dune areas; use and development within 50-year and 100-year Erosion Risk Zones can be undertaken in limited managed circumstances that maintain / enhance the natural buffering effect of the foredune area (Tauranga District Plan); Lowering of foredunes is to be avoided (Bay of Plenty Regional Coastal Environment Plan);
The ability of pohutukawa and other coastal cliff vegetation to maintain the stability of coastal cliffs is to be protected (Bay of Plenty Regional Coastal Environment Plan);
Subdivision, use and development should not compromise the integrity of natural defences to coastal hazards (Tauranga District Plan); natural features that buffer the effects of coastal hazards should be protected (Regional Coastal Environment Plan for the Canterbury Region);
Protect natural values and features that provide natural hazard protection; allowance should be made for the future inland migration of some natural features as a result of coastal processes (including sea level rise) (Bay of Plenty Regional Coastal Environment Plan); protect, maintain and enhance natural buffers that defend against the adverse effects of coastal hazards (Wairoa Coastal Strategy);
Any new development in the coastal environment should be designed or located in such a way that the need for coastal protection works is minimised (Regional Coastal Environment Plan for the Canterbury Region); new subdivision, use and development should be so located and designed that the need for hazard protection works is avoided. (NZCPS, Policy 3.4.5);
Take a precautionary approach to the installation of coastal hazard protection works - including consideration of abandonment / relocation of existing structures, and using soft protection works (Bay of Plenty Regional Coastal Environment Plan); limit the use of physical protection measures to those areas where all other options have been exhausted and it is necessary to protect the community, infrastructure and/or public health and safety (Wairoa Coastal Strategy);
Network utility infrastructure and services should be provided for, subject to adverse effects being avoided, remedied or mitigated (Regional Coastal Environment Plan for the Canterbury Region); when assessing future upgrades of existing infrastructure include assessment of the option of relocation (Wairoa Coastal Strategy);
The following standards / criteria should be applied to the identification of coastal hazard areas: (Bay of Plenty Regional Coastal Environment Plan)
Erosion impacts of sea level rise: The Intergovernmental Panel on Climate Change best estimate, presently the IPCC 1995, IS92a scenario estimates (this is 0.49 metres by the year 2100), should be used.
Shoreline response to storm erosion and flooding: Scientifically appropriate models should be used, such as those based on, but not restricted to, the Bruun Rule.
Planning horizon: A 100-year planning horizon should be used.
Long term trend: This should be derived from cadastral, aerial photography, surveys, or other reliable historic data. The reference shore adopted should be the toe of the foredune where these land forms occur, or elsewhere should be the seaward limit of vegetation or some other datum as appropriate.
Short term fluctuation: This should be derived from the most reliable records available at the time for particular stretches of the coast, and should err on the side of caution.
Dune stability factor: This should be based on the angle of repose (AOR) of the dune sands as defined locally.
Factor of safety: The coastal hazard area assessment should include an appropriate factor of safety, either built into the above criteria and standards, or added on in the final stage in the calculation.
Any profiles (cross sections) should be carried out to accepted surveyors standards and practice. All levels must be in terms of mean sea level to Moturiki datum.
The following standards / factors should be applied when determining minimum ground levels or building platforms (for estuaries and harbours): (Bay of Plenty Regional Coastal Environment Plan)
Sea level rise which is currently 0.49 metres: The sea level rise should be the official best estimate by the Intergovernmental Panel on Climate Change (currently the IPCC 1995, IS92a scenario estimate of 0.49 metres) over a 100-year planning horizon.
Minimum annual exceedance probability of 2% (1% is recommended) - A 2% annual exceedance probability (AEP) means that those planning the development must design for a storm surge that has 2% chance of occurring in any one year (or on average, will occur once every 50 years). This is specified as a minimum standard. It is recommended that the 1% AEP standard is adopted for large new subdivisions, or sites where the value of assets at risk is high (or difficult to insure), or where there is infrastructure (e.g. pumping stations, electricity substations) which is important to the wellbeing of the community.
Tide level; barometric set up; and wind set up: It is recommended these factors are estimated as joint probabilities, by using an appropriate statistical technique.
Estuary effects: Estuary effects includes the dynamic effect of storm surge in estuaries, wave set up at the estuary mouth which forces water into estuaries and differential wind stress across estuaries. Allowance of 0.33 metres is recommended if specific information is not available.
Factor of safety (0.5 is recommended).
In carrying out hazard assessments or considering resource consent applications the possibility and implications of climate change are to be recognised. In particular the likelihood of the following matters should be considered: a change in sea level; altering of coastal processes; increased inundation of low lying estuarine areas; higher local temperatures; changes in rainfall patterns; and increase in cyclonic storms (Gisborne Combined Regional Land and District Plan).

Methods

The following methods have been identified in policy statements and plans to implement the policies:

Coastal Hazard Overlays in planning maps - covering extreme risk area, high risk area, moderate risk area, safety buffer (to cover coastal erosion beyond 2100), and Areas Subject to Coastal Hazard (Gisborne Combined Regional Land and District Plan);
Identify a coastal hazard erosion protection area and coastal protection area, within which development is restricted; prohibit subdivision and restrict development in the current erosion risk zone (Tauranga District Plan);
Manage the location of new buildings and require provision of alternative building sites within the 50-year and 100-year Erosion Risk Zones (Tauranga District Plan);
Require esplanade reserves upon subdivision and development of land abutting the foreshore, where it would mitigate natural hazards (Tauranga District Plan);
Investigations of actual and potential hazards - including regular data collection to determine changes in occurrence of natural events; preparing 5-yearly reports to territorial authorities on state of shoreline and changes in hazards, updating hazard maps at 10-year intervals (Regional Coastal Environment Plan for the Canterbury Region);
Information provision / education on adverse effects of certain activities on natural beach system and measures which reduce the degree of hazard (Regional Coastal Environment Plan for the Canterbury Region);
Coordination and joint action (with territorial authorities, DoC, iwi, interested / affected parties) to: (Regional Coastal Environment Plan for the Canterbury Region)
identify practicable alternative locations for developments in hazard zones
identify policies for district plans to reduce potential damage to properties in sea water inundation zones
consider alternatives for avoiding / mitigating coastal hazards.
Encourage local authorities and community groups to undertake beach and dune conservation programmes and to use indigenous species when carrying out restoration planting (Regional Coastal Environment Plan for the Canterbury Region);
Transfer of powers (under s33 RMA) where operation of rules governing activities in hazard zones can best be administered by the territorial authority (Regional Coastal Environment Plan for the Canterbury Region);
Regional rules - discretionary activities in coastal hazard zones: (Regional Coastal Environment Plan for the Canterbury Region)
The erection, reconstruction, placement, alteration, or extension of any structure;
The disturbance (burning, grazing, or removal) of vegetation within active beach systems;
The formation of access tracks (including board walks) across an active beach system;
The artificial adjustment of a beach profile, (including dune re-contouring), within an active beach system;
The excavation, filling, or disposal of spoil in volumes greater than 5 cubic metres per 100 square metres of land area;
The removal of sand, rocks, shingle, shell, or other natural material from an active beach system in volumes greater than 5 cubic metres by any person within any 12 month period.
Regional rules - prohibited activities in coastal hazard zones: (Regional Coastal Environment Plan for the Canterbury Region)
The erection or placement of any habitable building with a floor area greater than 25 square metres (or extension / alteration which causes the building to have a floor area greater than 25 square metres);
The construction of a landfill or the use of a landfill for the disposal of solid or hazardous waste;
The production or storage of any hazardous substance (with some exceptions);
The construction of a new road or railway, but not including: (i) the reconstruction or realignment of an existing road or railway within the hazard zone; or (ii) the construction of a new road or railway that provides an access route to the Coastal Marine Area.
Coastal hazard assessments for priority areas and particularly parts of the coastline subject to development pressure (Gisborne Combined Regional Land and District Plan);
Work with other statutory agencies to give legal protection to natural defence and buffer systems, this could include policies and rules regarding natural buffers in the Regional Coastal Plan (Wairoa Coastal Strategy);
Work with landowners to protect natural buffers and defence systems. This could include voluntary retirement, fencing of susceptible areas, investigating funding opportunities for enhancement of these areas (Wairoa Coastal Strategy);
Work with the community to define the opportunities and constraints from natural hazards in each coastal area. This should be done as part of community/structure planning. Key recommendations could include guidelines for development or protection in areas at high risk from coastal hazards (Wairoa Coastal Strategy);
Work with and support other agencies to identify and confirm sites at risk from natural hazards (Wairoa Coastal Strategy);
Require that information on effects from natural hazards provided with resource consent applications contribute to a database of hazards (Wairoa Coastal Strategy);
Identify infrastructure at risk (e.g. roading) from natural hazards and alternative locations for this infrastructure. This should include the feasibility of securing the land so that 'retreat' is available as the preferred option (Wairoa Coastal Strategy);
Inform and educate landowners and developers regarding natural hazards and their consequences and disseminate information on possible solutions (Wairoa Coastal Strategy);
Adopt a 'hierarchy of options' to manage risk from coastal hazards, including the following assessment options (1=most preferred, 4=least preferred): (Wairoa Coastal Strategy)

1. Activities (e.g. beach accessways) and land use practices to protect natural barriers such as sand dunes, gravel ridges, cliffs, salt marshes and other vegetation.

2. Management of land use to avoid areas of coastal hazard (e.g. location of development away from coastal hazards, retreat or relocate infrastructure).

3. Undertake 'soft defence works' such as revegetation, or beach nourishment.

4. Undertake 'hard structural works' such as seawalls, rock armouring or groynes.

Require adequate assessment of effects on natural hazards to be provided with applications for resource consents. This should make sure that new subdivisions and infrastructural developments are located and designed to avoid the need for hazard protection. This could be included as an evaluation criteria in the District Plan, as part of a request for further information, or via a variation to the District Plan (Wairoa Coastal Strategy);
Esplanade strips, wider esplanade reserves and generous building setbacks are to be protected and provided in areas where significant actual or potential coastal erosion hazards exist and/or in areas of high risk (Wairoa Coastal Strategy);
Ongoing monitoring (Tauranga District Plan);
Maintain and update hazard register;
Managed retreat.

Comment

Our research has shown that coastal hazards are well recognised and there are many provisions in strategies and plans aimed at managing coastal erosion and inundation of land from seawater. The plan provisions cover objectives, policies and methods, and standards that look to identify and map areas, reduce the risk of coastal hazards, manage effects, provide buffers, identify engineering solutions, and control activities by consent activity status and using standards.

The Canterbury Regional Coastal Plan is one of the few plans that contains hazard controls for areas inland of the mean high water springs (MHWS). The Draft Hawke's Bay Regional Coastal Environment Plan also defines a wider coastal environment including: the coastal marine area; tidal waters and foreshore above MHWS; dunes; beaches; coastal cliffs; and other areas where activities occur or may occur which have a direct physical connection with, or impact on, the coast.

Tauranga District Council, Wairoa District Council, Environment Canterbury and Environment Bay of Plenty provide good examples of best practice for coastal hazards.

Overall we consider that there is a wealth of best practice examples in the plans reviewed to develop model objectives, policies and methods applicable to natural coastal hazards for any best practice guide developed in the future.

Other mechanisms

The following other mechanisms may be used to assist with the management of natural coastal hazards:

Development setbacks e.g. Environment Waikato report on recommended setbacks for Coromandel beaches (Environment Waikato, 2002a);
LIMs and PIMs to provide information on location and/or characteristics of known hazards;
Apply provisions of Building Act to buildings and structures in natural hazard areas
Building guidelines to assist resource consent applicants to identify acceptable design solutions (Tauranga District Plan);
Non-statutory plans e.g. Environment Waikato Coastal Erosion Risk Mitigation Plan (Environment Waikato, 1999a) and Coastal Flooding Risk Mitigation Plan (Environment Waikato, 1999b) - defining roles and future directions of management across different authorities and the community;. Rodney District Council's Omaha Coastal Compartment Management Plan (Rodney District Council, 2003) which identifies local issues and intended actions for the coastal 'compartment';
Review (e.g. every 5 years) the physical extent of coastal hazard zones (Tauranga District Plan);
Manage beach access to minimise human impact on identified sensitive frontal dunes (Tauranga District Plan, Gisborne Combined Regional Land and District Plan);
Programme beach replenishment, nourishment and restoration works (through Annual Plan and LTCCP) (Tauranga District Plan);
National Policy Statements;
Education programmes to improve knowledge and promote awareness and avoidance or mitigation measures;
Advice and advocacy e.g. best practice guidelines;
Engineering solutions e.g. sea walls;
Lifeline engineering projects to assess vulnerability of lifelines and develop contingency and response plans
Emergency management planning, including warning systems;
Emergency works;
Research, scoping studies, hazard vulnerability studies, risk assessments;
Charges / financial contributions;
Acquire / purchase land (Annual Plan, LTCCP).

9.2.3 Earthquake (seismic) hazards

New Zealand has a considerable history of seismic events, and physical features influenced by this seismic activity. Major earthquake fault lines are defined, with smaller faults being surveyed regularly as development occurs on/adjoining them. Earthquakes cannot be modified, therefore planning approaches can only reduce community vulnerability.

National structural standards exist to minimise the effects of earthquakes on communities.

Identification of hazard

Ground shaking; surface movement on a fault line causing ground deformation and destruction/damage to structures built across the fault line or within the crush zone; secondary effects such as landslides, flooding, liquefaction.

Policy statement or plan approach

Objectives

The following outcomes are sought in the objectives:

To minimise the risks of earthquakes affecting people and property in the District as far as practicable (Matamata-Piako District Plan and a number of other plans).

Policies

The following ways of achieving the objectives have been identified:

Ensure appropriate uses, zones and performance standards are developed for areas known to be liable to .... ground rupture from faults (Kapiti Coast District Plan);
Take a precautionary approach to development in suspected risk areas until further information on the extent and nature of earthquake risk becomes available (Matamata-Piako District Plan);
Area at risk from fault rupture causing permanent ground deformation along the Wellington Fault be managed by the Wellington Fault Special Study Area to address the effects of subdivision and development on the safety of people and their property (City of Lower Hutt District Plan);
Suitable engineering and emergency management measures be adopted to safeguard people and their property from liquefaction, ground shaking and tsunami hazards (City of Lower Hutt District Plan).

Methods

The following methods have been identified in plans to implement the policies:

Seek opportunities to increase knowledge about seismic hazards (Gisborne Combined Regional Land and District Plan); Identification and monitoring of the effects of earthquakes, research will continue to be carried out over the life of the District Plan (Hastings District Plan);
Regional scale assessments of the various components of seismic hazard including surface fault rupture, ground shaking, tsunami, liquefaction and ground damage, landslides, and locally significant hazards (Regional Policy Statement for the Wellington Region);
Maintain and update hazard register (various plans);
District Plan outlines an Earthquake Resource Management Unit (RMU), consisting of areas identified as being prone to seismic hazard. Rules will apply in this area in the future to prevent or restrict land use (Hastings District Plan);
Mapping of fault avoidance zones:
Active fault lines and susceptibility of areas to liquefaction and ground shaking amplification from earthquakes are identified for informational purposes in District Plan Appendices (Hastings District Plan);
Hazard (Fault Line) Areas identified on planning maps, 1:3,000 scale, including 20 metre buffer zone either side of the likely fault rupture hazard zone (Wellington City District Plan);
Fault maps should be at a minimum scale of 1:10,000 (Ministry for the Environment, 2003b).
A minimum buffer zone of 20 metres either side of the known fault trace or likely fault rupture zone is recommended (Ministry for the Environment, 2003b).
Ground shaking hazard maps to show the geographic variation in ground shaking hazard that could be expected during certain earthquake events (Greater Wellington Regional Council website: www.gw.govt.nz);
Requirement to provide a geotechnical report and engineering design report for resource consent applications for developments within hazard (fault line) area. The engineering design report must detail additional engineering measures that will be adopted to mitigate potential adverse effects from a fault rupture hazard event (Wellington City District Plan);
Allow only one residential unit as a permitted activity in hazard (fault line) area (Wellington City District Plan);
In any Hazard (Fault Line) Area, residential buildings shall have a maximum height of 8m and be built with a light roof and light wall cladding (Wellington City District Plan);
Multi-unit development within the Hazard (Fault Line) Area classified as a Discretionary (Unrestricted) Activity (Wellington City District Plan);
Assessment criteria for rules including: (Wellington City District Plan)
Whether the development is located in the fault rupture hazard area, and the extent to which the siting and layout of the development will reduce the effects of fault rupture on the safety of occupiers and neighbours;
The extent to which a geotechnical report and an engineering design report shows that the risk of building failure following a fault rupture on the safety of the occupiers and neighbours;
Construction, alteration and addition to buildings or structures exceeding a gross floor area of 30m� within a Hazard (Fault Line) Area is a Discretionary Activity (Restricted) in respect of the location and type of buildings or structures (Wellington City District Plan);
Methods which become more permissive as risk of fault rupture decreases e.g. greater range of buildings allowed, less restrictive consent activity category, more use of Building Act controls, more use of non-regulatory approaches e.g. education (Ministry for the Environment, 2003b);
Determine consent category for buildings within a fault avoidance zone based on risk assessment. As risk increases, consent category becomes more restrictive. Evaluate risk using:
fault recurrence interval
fault complexity
Building Importance Categories (based on risk levels for building collapse according to building type, use and occupancy)
the risk the community is prepared to accept

(Ministry for the Environment, 2003b)

Rules in the district plan can allow development in a fault avoidance zone only if resource consent is granted. This approach is suitable for well-defined faults, or distributed faults that have been accurately located (Ministry for the Environment, 2003b);
Building within a fault avoidance zone should be discouraged wherever possible (Ministry for the Environment, 2003b);
Restricted discretionary activity (City of Lower Hutt District Plan):
All structures and buildings on any site where the whole site or a portion of the site falls within the Wellington Fault Special Study Area, excluding the following: Proposed accessory buildings which are not required for habitable or working purposes, or Utilities including associated uninhabited buildings, which are Permitted Activities. Discretion restricted to: Safe Separation Distance of Structures and Buildings from the Wellington Fault: For all structures and buildings, an engineering report will be required to confirm that the Wellington Fault is not within 20.0m of any proposed structure or building, or that the necessary engineering precautions have been taken.
Controlled activity: (Kapiti Coast District Plan)
Any building which is within 20 metres of an earthquake fault trace as shown on the Planning Maps. The matters over which the Council reserves control are: The imposition of conditions to ensure appropriate engineering design to avoid, remedy or mitigate any adverse effects resulting from ground rupture.
The district plan may have to include provisions to ensure that the risk is not increased by intensified land use (such as urban infill) or by new building on sites not already occupied. It can also require geotechnical investigations and appropriate earthquake-resistant design where appropriate (Ministry for the Environment, 2003).

Comment

Provisions in plans to address hazards from seismic events have been developed over the past 20 years. Advances in research and geological information have also assisted with management options. Our research has shown that the approaches adopted in plans centre on identification and mapping of fault avoidance zones; establishing rules to control activities and development; establishing standards and assessment criteria to assess individual consents in fault avoidance zones. There appears to be a good link between the RMA and Building Act, and between planning and engineering solutions.

While we consider these approaches are sound, the research has shown a variance between plans as to whether activities should be allowed within avoidance zones, and a variance in the activity status of such activities. For example, we question the controlled activity status adopted by the Kapiti Coast District Plan as being good practice. Alternatively, we consider the plan provisions adopted by the Hutt City Council, Hastings District Council, Wellington City Council and Greater Wellington provide good examples of best practice for earthquake (seismic) hazards.

When preparing a best practice guide on earthquake (seismic) hazards, we also recommend that the following matters be considered:

an effective approach requires RMA and Building Act methods (Ministry for the Environment, 2003);
specific earthquake objectives and policies should be developed;
rules need to be based upon risk and the approach used in built-up areas should differ from the approach used in a greenfield area (Ministry for the Environment, 2003);
existing use rights under the RMA also mean that when an existing building over a fault is damaged or burnt down, or requires rebuilding for whatever reason, it can be rebuilt, even once the risk has been realised (Ministry for the Environment, 2003);
linkages between earthquakes and secondary effects (landslips, flooding, liquefaction) could be better defined.

Other mechanisms

The following other mechanisms may be used to assist with the management of earthquake hazards:

Non-statutory plans e.g. Environment Waikato Earthquake Risk Mitigation Plan (Environment Waikato, 1997a) - defining roles and future directions of management across different authorities and the community;
Building Act measures and controls e.g. earthquake prone building policy - all territorial authorities are required to have such policy under the Building Act 2004. The policy must state: the approach that the Council will take in performing its functions under the Building Act 2004; the Council's priorities in performing those functions; and how the policy will apply to heritage buildings.
Building Importance Categories (BIC) can be used to make decisions on resource consents and to require conditions on buildings within fault avoidance zones (Ministry for the Environment, 2003b);
Non-regulatory methods: (Ministry for the Environment, 2003b)
purchasing at-risk land for passive recreational purposes
exchanging at-risk land with land that can be put to some other purpose
allowing greater development rights if land is retired or covenanted
taking at-risk land as a condition of subdivision consent (reserves contribution)
using financial incentives (for example, rates relief on at-risk land if it isn't built upon)
promoting and helping fund the use of covenants (privately or through the QEII National Trust) for the voluntary protection from development of open space on private land.
LIMs and PIMs to provide information on location and/or characteristics of known hazards;
Education programmes to improve knowledge and promote awareness and avoidance or mitigation measures;
Advice and advocacy (e.g. best practice guidelines);
Earthquake monitoring;
Emergency management planning;
Emergency works;
Engineering solutions;
Lifeline engineering projects to assess vulnerability of lifelines and develop contingency and response plans
Acquire / purchase land (Annual Plan, LTCCP).

9.2.4 Flooding Hazards

In general, plans identify two types of flooding - lowland and plains areas flooded by rivers, and coastal areas flooded by sea water inundation. Coastal hazards are addressed in section 9.2.2. above.

Identification of hazard

Large areas of land subject to some degree of flooding risk, including settlements.

Policy statement or plan approach

Objectives

The following outcomes are sought in the objectives:

Minimise the adverse effects to property and the environment from flooding (Tauranga District Plan);
Avoid further non-essential development or redevelopment in the most hazard prone locations of the district (Timaru District Plan);
Mitigate effects in floodable areas other than most hazard prone locations(Timaru District Plan).

Policies

The following ways of achieving the objectives have been identified:

Prevent development in most hazard prone areas while allowing redevelopment with designs/modifications to reduce risk (Timaru District Plan); avoid development in low-lying, possibly flood-prone areas, or permit only when risk from flooding to buildings / structures is avoided or fully mitigated (Tauranga District Plan)
Encourage relocation to alternative sites (plan changes promoted by Council to assist)(Timaru District Plan);
Limit further rezoning for residential development (Timaru District Plan);
Construction standard of 0.5% chance of flood reaching floor level in any one year (Timaru District Plan);
Development shall be discouraged in flood hazard zones unless it can be demonstrated that all habitable floor levels are protected from the 1% AEP flood level, and that structures in the 1% AEP flood level do not divert overland flows onto neighbouring properties (Auckland Regional Policy Statement);
Setback of buildings from stop banks (Timaru District Plan);
Mitigation through design and location (Timaru District Plan);
When developing plan provisions, or assessing resource and building consent applications, Council will adopt 'design flood standards' for flood hazard assessments e.g. peak flood flows, 100 year return period (Gisborne Combined Regional Land and District Plan);
To impose appropriate standards on the subdivision, use and development in areas identified on the Hazard Information Maps as being subject to a high degree of risk from either riverine inundation or sea level rise/storm surge (Invercargill City District Plan);
To control the erection of, and extensions to, residences within areas identified on the Hazard Information Maps as being subject to a high degree of risk from either riverine inundation or sea level rise/storm surge (Invercargill City District Plan);
In assessing any resource consent for subdivision, use or development in areas identified on the Hazard Information Maps as being subject to a high degree of risk from either riverine inundation or sea level rise/storm surge, to take into account: (Invercargill City District Plan)
the degree of risk of flooding to the property;
the effects of flooding on the proposed development;
alteration to the water flow pattern;
the length of time that a building will be on the site;
the extent of any adverse effect from either riverine inundation or sea level rise/storm surge on residences; and
the need for new or upgraded hazard protection works and the effects of those works.
That suitable engineering, emergency management and land use control measures be adopted to reduce the vulnerability of people and their property to flood hazards (City of Lower Hutt District Plan);
When carrying out flood mitigation works, existing vegetation shall be retained, where appropriate, to aid stability and maintain environmental quality. However, the planting of vegetation, which may, because of growth habit, restrict water flow and exacerbate the flooding hazard, shall be avoided (Auckland Regional Policy Statement).

Methods

The following methods have been identified in plans to implement the policies:

Rules prohibiting new household units in the most flood prone locations (while allowing reconstruction of existing units), and limiting alterations to existing units to modifications intended to reduce flood damage (Timaru District Plan);
Cooperating with investigations of alternative locations and promoting district plan changes to assist people to move to sites less prone to natural hazards; (Timaru District Plan);
Limiting zoning of additional land in flood plains (for urban purposes) to those areas where no practical alternative exists for the expansion of major settlements (Timaru District Plan);
Rule for residential activities requiring floors to be constructed above a flood with a 0.5% chance of occurrence in any one year (Timaru District Plan); minimum building floor height (Tauranga District Plan);
Rule for minimum habitable floor level based on height over design flood standard, or 300mm-1.0m above general ground level, or 200-300mm above flood levels - depending on location (Gisborne Combined Regional Land and District Plan);
Discretionary activity status given to: (Timaru District Plan)
erection of buildings/structures on landward side of stopbank, within 100 metres of the centreline of the stopbank;
erection of buildings/structures on land subject to a risk of flooding which exceeds 2% in any year.
Prohibited activity status given to household units and other residential activities on the river side of a stopbank (Timaru District Plan);
Require subdivision and development to identify and protect secondary flowpaths in their location and design (Tauranga District Plan);
Flood hazard overlays in planning maps covering different types and scales of flood hazards such as: River and Floodway; Flood Ponding Areas; Flood Fringe Areas; Old River Loops; Urban Stormwater Flood Hazard Area; and Urban Floodways (Gisborne Combined Regional Land and District Plan);
Regional rules - restricted discretionary activities in flood hazard zones: (Gisborne Combined Regional Land and District Plan):
annual cropping except maize and sweetcorn (river and floodway zone);
any activity in the road reserve that may result in the diversion or ponding of floodwaters, including any new road, road alteration or shape correction (most zones);
new fencing other than temporary electric fencing and boundary fencing and boundary fencing (river and floodway zone); any new, or alterations to existing, solid fence along any property boundary (urban stormwater and urban ponding hazard areas);
construction of soil conservation and river control works (moderate/high hazard zone, river and floodway zone);
earthworks which alter the level of the land (most zones);
planting of trees or shrubs (river and floodway zone); planting of trees or shrubs on the banks/berms of rivers or streams (urban floodway zone);
construction or installation of network utility structures (most zones);
construction, relocation, additions / alterations of/to buildings (most zones);
the installation or alteration of culverting or bridging of streams, watercourses or rivers. (river and floodway zone, urban floodway zones);
establishment of woodlots, shelter belts or new permanent horticulture (moderate/high hazard zone);
with discretion restricted to:
restriction or diversion of the passage of floodwaters;
aggradation of the bed or berms of the rivers;
the endangering of lives or property in the event of flooding.
Regional rules - prohibited activities in flood hazard zones: (Gisborne Combined Regional Land and District Plan):
the construction of all new buildings (except network utilities), and addition to or alteration of existing residential buildings (river and floodway zone); construction and relocation of residential buildings (old river loops); construction / addition of/to any building/structure not provided for in other rules;
commercial horticulture involving perennial tree or shrub species (river and floodway zone);
artificial shelter belts (river and floodway zone);
cropping of maize or sweetcorn (river and floodway zone);
deposition of any lawn clippings, tree prunings or any other waste material (urban floodway zone);
raising the level of land by the depositing of materials (urban floodway zone).
Identify a minimum floor level for those areas subject to a high degree of risk from either riverine inundation or sea level rise / storm surge, within which residences must comply with appropriate performance standards (Invercargill City District Plan);
Maintain and update hazard register (various plans).

Comment

Similar to earthquake hazards, policy statement and plan provisions for flooding have developed over a considerable time period, and provisions are well developed. The general approach taken to flooding is to identify and map flood prone areas; identify a management approach depending on the risk - prevent / avoid; alternative sites and relocation; allow development and use subject to standards and assessment criteria. These management approaches are supported by rules in plans that determine activity status, and several plans adopt prohibited activity status where the risk is considered too great. In principle we question whether adopting the prohibited activity approach is best practice as we consider full discretionary or non-complying activity status is sufficient to address the concerns associated with flooding.

Overall we consider that there are a number of best practice examples in the plans reviewed to develop model objectives, policies and methods applicable to flooding hazards for any best practice guide developed in the future. We consider that the Timaru and Gisborne District Councils provide good examples of best practice for flooding hazards.

Other mechanisms

The following other mechanisms may be used to assist with the management of flooding hazards:

engineering solutions e.g. stop banks and structures;
lifeline engineering projects to assess vulnerability of lifelines and develop contingency and response plans
river bank plantings;
investigations of alternative locations for activities;
limiting of zoning of additional land in flood prone areas for urban purposes;
LIMs and PIMs to provide information on location and/or characteristics of known hazards, and advice on building options to mitigate risk of flooding;
education programmes to improve knowledge and promote awareness and avoidance or mitigation measures;
non-statutory plans e.g.
Environment Waikato Flood Risk Mitigation Plan (Environment Waikato, 1997b) and Coastal Flooding Risk Mitigation Plan (Environment Waikato, 1999b) - defining roles and future directions of management across different authorities and the community.
Hutt River Floodplain Management Plan (Wellington Regional Council, 2001) - strategic solutions to manage flood risk in the Hutt Valley (regional council and two territorial authorities)
research, risk assessments;
advice and advocacy e.g. best practice guidelines;
apply provisions of Building Act to buildings and structures in natural hazard areas;
monitoring e.g. rainfall and river;
flood control functions under the Soil Conservation and Rivers Control Act 1941;
notices on the property (under the Building Act) where buildings are erected in the high risk areas for riverine inundation or sea level rise/storm surge (Invercargill City District Plan);
National Policy Statements;
emergency management planning, including flood warnings;
emergency works;
charges / financial contributions;
acquire / purchase land (Annual Plan, LTCCP).

9.2.5 Geothermal Hazards

While geothermal areas in New Zealand are well documented, researched and monitored, there is always an uncertainty as to when and where natural hazards from geothermal areas will occur. This uncertainty makes management difficult. Geothermal activity can include a number of unique hazards including discharges of geothermal fluid, condensates and gases.

Identification of hazard

Discharge of geothermal fluid, condensates and gases and the environmental effects associated with such a discharge; secondary effects such as land subsidence / slip; lack of information on resource.

Policy statement or plan approach

Objectives

The following outcomes are sought in the objectives:

Risks associated with geothermal natural hazards are avoided or mitigated and the adverse effects on the environment of unnatural discharges of geothermal energy, fluid, condensates and gases are avoided or remedied (Bay of Plenty Regional Policy Statement);
The protection of geothermal surface features, the restoration of geothermal surface features outflow activity and the avoidance or mitigation of natural geothermal hazards (Rotorua Geothermal Regional Plan).

Policies

The following ways of achieving the objectives have been identified:

To ensure that effective measures are undertaken to avoid, remedy or mitigate any adverse effects resulting from development sites known to have high actual or potential geothermal hazard risk (Bay of Plenty Regional Policy Statement);
To encourage all resource users to use safe practices when using geothermal resources (Bay of Plenty Regional Policy Statement);
To ensure that the public, particularly tourists and developers, are made aware of the hazards associated with geothermal sites and the use of geothermal resources (Bay of Plenty Regional Policy Statement);
To ensure that any adverse effects of unnatural discharges of geothermal fluid, condensates and gases are avoided or remedied (Bay of Plenty Regional Policy Statement);
To actively encourage geothermal fluid diversion or re-injection that returns fluid into its source reservoir, subject to an assessment of effects (Bay of Plenty Regional Policy Statement);
To avoid, remedy or mitigate natural hazard caused by interference with geothermal activity or geothermal surface features, formal resource consent assessments and tests are to be applied on the effects of development on geothermal surface features present in a development area, with particular regard to the effects of development on geothermal hazard risk (Rotorua Geothermal Regional Plan);
To require the provision of formal planning assessment of the effects of development on geothermal hazard risk in relevant planning documents (Rotorua Geothermal Regional Plan);
Apply a precautionary approach where there is scientific uncertainty and a threat of serious adverse effects to other natural and physical resources including overlying structures (the built environment) (Waikato Regional Policy Statement).

Methods

The following methods have been identified in plans to implement the policies:

The following activities shall be administered as activities that increase the risk of natural hazard, and have an adverse effect on the environment. They shall be regulated as discretionary activities requiring a land use consent: (Rotorua Geothermal Regional Plan (for the Rotorua Geothermal Field); Rotorua District Plan (for the entire Rotorua district))
any interference with the natural geothermal fluid outflow from a geothermal surface feature;
any interference with the physical structure of a geothermal feature;
any destruction of a geothermal feature including excavation;
any placement or deposition of any substance, including fill or waste material on, into, or under any geothermal surface feature.
When considering resource consent applications, apply conditions that reflect the state of knowledge about the system concerned and about the scale of likely adverse effects to other natural and physical resources including overlying structures (the built environment) (Waikato Regional Policy Statement);
Maintain and update hazard register.

Comment

Our research shows that there are fewer provisions relating to managing natural hazards relating to geothermal resources. This is likely to be a result of the localised occurrences of geothermal activity within a small number of districts. In particular it is notable that preventing or avoiding activities in known geothermal areas is not a current approach adopted in plans (unlike flooding/coastal areas above). The approach in plans is to allow activities and manage the effects and protect the resource. Rules and activity status provide the mechanisms to implement these policies.

In our view, while the existing provisions will be useful for preparing a best practice guide, we consider that a greater emphasis should be given to identifying and assessing the actual and potential effects of the natural hazards associated with geothermal resources, and look to adopt a more precautionary approach where the risks are identified than currently promoted in plans.

We consider Environment Bay of Plenty provides good examples of best practice for geothermal hazards, subject to our comments above.

Other mechanisms

The following other mechanisms may be used to assist with the management of geothermal hazards:

Engineering solutions;
Lifeline engineering projects to assess vulnerability of lifelines and develop contingency and response plans
LIMs and PIMs to provide information on location and/or characteristics of known hazards;
Education programmes to improve knowledge and promote awareness and avoidance or mitigation measures;
Research, scoping studies, hazard vulnerability studies, risk assessments;
Advice and advocacy e.g. best practice guidelines;
Monitoring;
Emergency management planning, including warning systems;
Emergency works;
Acquire / purchase land (Annual Plan, LTCCP).

9.2.6 Landslides / land instability / subsidence hazards

The natural hazards of landslides / land instability / subsidence are linked to other hazards addressed in this research (e.g. seismic and meteorological events), and there is a degree of overlap in policy statement and plan provisions relating to these hazards.

Identification of hazard

Risk to life, property and the environment resulting from land slippage / instability / subsidence.

Policy statement or plan approach

Objectives

The following outcomes are sought in the objectives:

To reduce risk to life, property and the environment resulting from use and development of land subject to, or likely to be subject to, instability (Tauranga District Plan);
To avoid adverse effects from induced subsidence of peat areas / highly compressible soils (Tauranga District Plan);
To minimise the adverse effects of natural hazards and coal mining subsidence on people and property; to ensure future residential development in Huntly is not detrimentally affected by possible subsidence as a direct consequence of coal mining activity; to ensure land subdivision takes into account the topography, building platforms, and potential natural hazards and coal mining subsidence (Waikato District Plan).

Policies

The following ways of achieving the objectives have been identified:

Areas particularly at risk from known instability problems shall be identified in the district plan (Gisborne Combined Regional Land and District Plan);
Avoid subdivision, use and development in areas prone to land instability where those activities are likely to accelerate, worsen or cause damage to land, structures or the environment through slippage or erosion (Tauranga District Plan);
Activity on peat areas / highly compressible soils should avoid altering drainage patterns and/or physical characteristics of the peat/soil (Tauranga District Plan);
Subdivision, use and development in areas prone to land instability to provide a full Assessment of Environmental Effects identifying what activity is appropriate (Tauranga District Plan);
That where areas susceptible to landslide have been identified, appropriate conditions of compliance will be provided to mitigate the adverse effects of subdivision and development on the vulnerability of people and their property (City of Lower Hutt District Plan);
Stormwater discharges directly to ground should occur only where ground conditions are identified as being suitable to receive and absorb discharges without adversely affecting land stability of the site or cumulatively on land in the vicinity of the discharge point(s) (Tauranga District Plan);
That natural hazards and coal mining subsidence be identified and subdivisions designed to safeguard future residents from these potential hazards (Waikato District Plan).

Methods

The following methods have been identified in plans to implement the policies:

Mapping of areas prone to land subsidence (e.g. Waikato District Plan (coal mining subsidence) and a number of other plans)
Require site investigations of land prone to instability before subdivision or building consent will be considered (Tauranga District Plan);
Avoid urban zoning of peat lands or other compressible soils wherever possible (Tauranga District Plan);
General regional rules for land instability zones (Gisborne Combined Regional Land and District Plan):
land disturbance shall not exceed 1m3 in any 3 month period, except for land disturbance directly associated with the construction of a building platform.
vegetation shall not be removed if the vegetation is more than 2m high, and vegetation removal shall not exceed 10m2 in any 12 month period.
stormwater discharges shall be designed and constructed to avoid erosion of riverbanks.
Council will consider land instability hazards during planning, design and construction of Council services (Gisborne Combined Regional Land and District Plan);
Collation of information into natural hazards register, and regular updating (Waikato District Plan);
Set back lines and buffer areas for cliffs being undermined and eroded by rivers (Palmerston North City District Plan).
Where there is doubt as to the stability of a site, or where areas have been identified in the natural hazards register as being liable to soil instability, the Council shall require as part of building or resource consents, a report from a suitably qualified engineer on the suitability of the site, and the stability of the foundations of the proposed buildings; On sites believed to be subject to gradual subsidence or where areas have been identified in the natural hazards register as being liable to gradual subsidence, Council shall require as part of a building or resource consent a report from a suitably qualified engineer. The buildings shall be constructed in such a manner that they will not be affected by subsidence and/or will be able to be maintained in the event of subsidence (Waikato District Plan);
Maintain and update hazard register.

Comment

Our research has shown that the approach taken in plans to landslides / land instability / subsidence is to reduce the risk, and avoid activities in areas prone to these hazards. The plan provisions relate to the identification and mapping of hazard areas, the need for site investigations, zoning to avoid development in areas subject to the hazards; and developing rules and standards to assess consents for activities in areas prone to these hazards. There is also a link to the Building Act requirements. Notwithstanding these measures, our experience is that there is not a consistent approach around New Zealand to managing activities in areas prone to landslides / land instability / subsidence. In addition, existing use rights may also cause issues when it comes to avoiding the hazards.

The provisions outlined in this section will be useful for preparing a best practice guide. However we consider that a greater emphasis should be given to identifying and assessing: actual and potential effects of the natural hazards associated with landslides / land instability / subsidence; methods to reduce the risk associated with such events; and methods to avoid activities in areas prone to these hazards. Where risks are identified in policy statements and plans, we recommend the adoption of a more precautionary approach than is currently promoted in plans. We also consider stronger links to Building Act provisions could be adopted.

We consider the Tauranga, Gisborne and Waikato District Councils' plans provide good examples of best practice relating to landslides / land instability / subsidence hazards.

Other mechanisms

The following other mechanisms may be used to assist with the management of landslides/land instability/subsidence hazards:

LIMs and PIMs to provide information on location and/or characteristics of known hazards;
Apply provisions of Building Act to buildings and structures in natural hazard areas;
Education programmes to improve knowledge and promote awareness and avoidance or mitigation measures;
Advice and advocacy e.g. best practice guidelines;
Monitoring;
Emergency management planning, including warning systems;
Emergency works;
Engineering solutions e.g. retaining walls;
Lifeline engineering projects to assess vulnerability of lifelines and develop contingency and response plans
Research, scoping studies, hazard vulnerability studies, risk assessments;
Charges / financial contributions;
Acquire / purchase land (Annual Plan, LTCCP).

9.2.7 Meteorological hazards

Meteorological hazards include floods, cyclones, storm surges, thunder- and hail-storms, rain- and wind-storms; blizzards and other severe storms; drought; desertification; lightning-induced fires; temperature extremes; sand- or dust-storms; permafrost; and snow or ice avalanches.

The impact of meteorological hazards has been increasing disproportionately with respect to other hazards and may be related to climate change. In New Zealand, the occurrence of some of these hazards has been linked to climatic patterns of El Ni�o Southern Oscillation (ENSO) and the Interdecadal Pacific Oscillation (IPO) (NIWA, 2004).

Identification of hazard

These hazards are weather-related events such as floods, droughts, sea-level rise, extreme wind, snow, frost, extreme temperature, hail, lightning and fire.

Policy statement or plan approach

Objectives

There are no specific objectives in the policy statements or plans that we have reviewed.

Policies

There are no specific policies in the policy statements or plans that we have reviewed.

Methods

The following methods have been identified in plans:

Undertake a scoping study on the hazards of severe wind and drought and set priorities for more detailed investigations of these hazards if the scoping study shows this to be warranted (Regional Policy Statement for the Wellington Region)

Comment

While no policy statements or plans reviewed specifically address meteorological hazards, we do note that plans do address some events under other hazards such as sea level rise relating to coastal hazards and flooding, and storm events relating to flooding of rivers.

We also note the following statement: "due to the unpredictable nature of meteorological hazards it is not possible to introduce any meaningful method of land-use planning control" (Waikato District Plan). We agree with this statement. Therefore, we consider the best approach is to address those meteorological hazards in specific areas (such as flooding) and not in a generic sense.

Other mechanisms

The following other mechanisms may be used to assist with the management of metrological hazards:

Measures designed to reduce the possibility of damage to property be instituted through the Building Act (Waikato District Plan); Building Act - require minimum standards to withstand wind loading;
Engineering and design solutions;
Lifeline engineering projects to assess vulnerability of lifelines and develop contingency and response plans
Research, scoping studies, hazard vulnerability studies;
LIMs and PIMs to provide information on location and/or characteristics of known hazards;
Education programmes to improve knowledge and promote awareness and avoidance or mitigation measures;
Advice and advocacy e.g. best practice guidelines;
Monitoring (MetService);
Emergency management planning, including warning systems;
Emergency works

9.2.8 Tsunami Hazards

New Zealand's extensive coastline, coastal settlements and off-shore faults make it vulnerable to a tsunami event that could have catastrophic consequences on life, property and the environment. While recent overseas tsunami events have raised an awareness of the tsunami risk, management of the effects of a tsunami hazard needs to be based on good research and science that quantifies risk and vulnerability.

Identification of hazard

Risk to life, property and the environment by inundation of sea water caused by a tsunami event.

Policy statement or plan approach

Objectives

The policy statements and plans reviewed as part of our research did not include specific objectives relating to tsunami events, or managing the effects of a tsunami hazard. Notwithstanding this, as outlined in 9.2.1 above, a number of plans do have generic objectives relating to natural hazards that could be seen as providing guidance for how the adverse effects of a tsunami event could be managed.

Policies

Our comment above regarding objectives in plans is also relevant to policies. The following specific ways of achieving the objectives have also been identified:

That suitable engineering and emergency management measures be adopted to safeguard people and their property from liquefaction, ground shaking and tsunami hazards (City of Lower Hutt District Plan);
To adopt a precautionary approach to the evaluation of risk in making decisions that affect the coastal environment, recognising that there will be situations where there is a low probability of an event occurring, but that such an event has the potential to create major adverse effects (Regional Policy Statement for the Wellington Region).

Methods

The following methods have been identified in plans to implement the policies:

Inundation Mapping - e.g. Wellington Region 'combined earthquake hazard maps' include land susceptible to tsunami inundation; Selwyn District Council Tsunami Response Plan includes a 'red zone' area identified as being subject to a tsunami event;
Regional scale assessments of the various components of seismic hazard including tsunami (Regional Policy Statement for the Wellington Region);
Undertake a scoping study on tsunami and set priorities for more detailed investigations if the scoping study shows this to be warranted (Regional Policy Statement for the Wellington Region);
National and regional research on tsunamis will be monitored on an ongoing basis and assessed as to its relevance to resource planning (Waikato District Plan);
The Plan will not specifically deal with tsunami except to the extent that the 60- metre coastal management area may mitigate the effects of any inundation (Carterton District Plan);
Managed retreat (refer to section 9.2.2: Coastal hazards);
Implement coastal hazard zones (refer to section 9.2.2: Coastal hazards).

Comment

Our research has shown that there is very little consideration given specifically to a tsunami event, and the management of the effects of this natural hazard, apart from mapping and taking a precautionary approach. There is no control or prevention of activities in areas vulnerable to tsunami effects. While some generic planning provisions may assist to address a tsunami event for a particular project on a particular site, in our view there is little best practice currently available in plans.

Notwithstanding this, we consider that a tsunami risk can be mitigated through land-use planning mechanisms, particularly if management approaches are adopted as included in Tonkin & Taylor's 2002 report (Tonkin & Taylor, 2002a). It is noted that a combined management / response approach is required as regulations and land-use planning are in reality unlikely to provide effective mitigation for the entire risk. An effective warning system and other mitigation options, such as protection and adaptation, are also required to address the residual risk through a layered defence. We consider any best practice guide should develop management and response options, with support by land use planning provisions to prevent or control activities in areas subject to a high tsunami risk.

In our view, Greater Wellington provides good examples of high level best practice for tsunami hazards.

Other mechanisms

The following other mechanisms may be used to assist with the management of tsunami hazards:

Emergency management planning i.e. monitoring and warning systems, evacuation planning, response plans e.g. tsunami contingency plans such as Gisborne District Council's Emergency Services Tsunami Contingency Plan (Gisborne District Council, 2005);
Research, scoping studies and technical reports;
Education programmes to improve knowledge and promote awareness and avoidance or mitigation measures;
LIMs and PIMs to provide information on location and/or characteristics of known hazards;
Engineering solutions such as sea walls, design special foundations; rock revetments, beach and fore-dune nourishment with external sand or gravel, or building up vulnerable coastal roads or causeways (Institute of Geological and Nuclear Sciences Ltd, 2005);
Adaptation (or accommodation) � dune and coastal vegetation restoration, plant or enhance coastal forests, re-create coastal/estuarine wetlands or marshes, raise and deepen foundations of dwellings, better tie-downs to foundation, open-up ground floors of engineered buildings (Institute of Geological and Nuclear Sciences Ltd, 2005);
Financial contributions for tsunami hazard mitigation works/services;
LTCCPs: (Institute of Geological and Nuclear Sciences Ltd, 2005)
assess and identify the need for areas that should be open space or passive use (e.g. because of tsunami risk) and have a purchase programme for such land;
discourage the location and design of critical community facilities and infrastructure in areas at risk from tsunami when undertaking a new development;
consider redevelopment and re-siting of community resources and infrastructure when due for renewal or replacement;
consult communities on desired outcomes for tsunami mitigation and preparedness strategies.
Lifelines engineering projects to identify the impacts of tsunami - this requires potential tsunami hazard to be assessed at a local scale;
Advice and advocacy e.g. best practice guidelines;
Emergency works;
Acquire / purchase land (annual plan, LTCCP);
Development controls e.g. control the location and nature of new development to mitigate tsunami effects, avoid new development in tsunami hazard areas, ensure that comprehensive development plans and / or AEEs consider tsunami risk for all coastal developments, and / or require resource consent applicants to provide information on tsunami-resistant designs or other mitigation measures for new developments within tsunami risk areas.
Maintain and update hazard register.

9.2.9 Volcanic Hazards

Along with the geothermal and earthquake seismic hazards, parts of New Zealand are subject to volcanic hazards which also present unique effects that need to be identified and managed. This is particularly difficult for parts of New Zealand where volcanic activity is now dormant, but may reoccur in the future.

Identification of hazard

Risk to life, property and the environment from volcanic eruptions (molten lava, ash and gases) and lahars.

Policy statement or plan approach

Objectives

The policy statements and plans reviewed as part of our research did not include specific objectives relating to volcanic events, or managing the effects of a volcanic hazard. Notwithstanding this, as outlined in 9.2.1 above, a number of plans do have generic objectives relating to natural hazards that could be seen as providing guidance for how the adverse effects of a volcanic event could be managed.

Policies

Our comment above regarding objectives in plans is also relevant to policies. The following ways of achieving the objectives have been identified:

To manage development occurring on land subject to, or at risk from, erosion, avulsion, alluvion, subsidence, inundation, slippage, volcanic or seismic induced flooding that will be adversely affected by those events (Ruapehu District Plan).

Methods

The following methods have been identified in plans to implement the policies:

Maintain and, where appropriate, extend rainfall, river and volcanic seismic monitoring systems;
Map those areas at risk from volcanic hazards (Regional Policy Statement for Manawatu-Wanganui);
Provide measures to avoid or mitigate volcanic, flood, seismic, subsidence and tsunami hazards. These may include controls on land use and subdivision;
Maintain and update hazard register.

Comment

Our research has shown that there is very little consideration given specifically to a volcanic event, and the management of the effects of this natural hazard, apart from mapping and monitoring. There is no control or prevention of activities in areas vulnerable to volcanic effects. While some generic planning provisions may assist to address a volcanic event for a particular project on a particular site, in our view there is little best practice currently available in plans.

We are aware that to date councils with active volcanoes in the region/district have been addressing the management of the effects of the hazard through engineering solutions / emergency management / monitoring. We consider any best practice guide should develop management and response options, with support by land use plan provisions to prevent or control activities in areas subject to a high volcanic risk.

Other mechanisms

The following other mechanisms may be used to assist with the management of volcanic hazards:

Management plans e.g. Lower Tongariro River Natural Hazard Management Plan (Tonkin & Taylor, 1998) - this plan defines the extent of the hazard, provides / assesses management options (land-use and engineering approaches), and sets a strategy for ongoing management;
Engineering solutions;
Lifeline engineering projects to assess vulnerability of lifelines and develop contingency and response plans
Non-statutory plans e.g. Environment Waikato Volcanic Risk Mitigation Plan (Environment Waikato, 1999c) - defining roles and future directions of management across different authorities and the community;
Research, volcanic hazard risk assessments e.g. Hipaua steaming cliffs;
Education programmes to improve knowledge and promote awareness / preparedness and avoidance or mitigation measures;
Mapping (outside district / regional plans) intended for emergency management and/or educational purposes rather than land-use planning, e.g.
Environment Waikato maps on lahar and ashfall zones (www.ew.govt.nz);
Auckland Regional Council volcanic hazards map (www.arc.govt.nz).
Monitoring and recording e.g. seismic (by the Institute of Geological and Nuclear Sciences, Taranaki Regional Council, Auckland Regional Council); ground deformation, volcanic eruptions and other geological events (by the Institute of Geological and Nuclear Science);
Building codes for ash fall e.g. require roofs to have steeper pitches;
Attaching to building consents under the Building Act, conditions relating to structural requirements for flood, wind, fire, earthquake and volcanic hazards;
Emergency management planning including warning systems - the Eruption Detection System (EDS) and the Eastern Ruapehu Lahar Alarm and Warning System (ERLAWS) are operative. The former provides warning of eruption lahars, particularly on Whakapapa Ski Area, and other volcanic hazards. The latter provides warning of lahars down Whangaehu Valley and on the eastern flanks of the park. The Department of Conservation operates both in conjunction with concessionaires, agencies and communities;
LIMs and PIMs to provide information on location and/or characteristics of known hazards;
Advice and advocacy e.g. best practice guidelines;
Emergency works;
Acquire / purchase land (Annual Plan, LTCCP);
Prevent development in zones that are of high risk to volcanic hazards.

9.3 Sources of information

The sources of information listed below have been used in the preparation of this section. Please refer to the 'References and bibliography' section of the report for full references.

Local government plans

Auckland Regional Council (1999) - Auckland Regional Policy Statement

Carterton District Council (2000) - Carterton District Plan

Environment Bay of Plenty (2003) - Bay of Plenty Regional Coastal Environment Plan

Environment Bay of Plenty (1999a) - Bay of Plenty Regional Policy Statement

Environment Bay of Plenty (1999b) - Rotorua Geothermal Regional Plan

Environment Canterbury (2005) - Regional Coastal Environment Plan for the Canterbury Region

Environment Waikato (2000) - Waikato Regional Policy Statement

Gisborne District Council (2006) - Combined Regional Land and District Plan

Gisborne District Council (2005) - Gisborne District: Emergency Services Tsunami Contingency Plan

Greater Wellington (1995) - Regional Policy Statement for the Wellington Region

Hastings District Council (2003) - Hastings District Plan

Hawke's Bay Regional Council (2004) - Hawke's Bay Regional Coastal Environment Plan (Draft)

Horizons Manawatu-Wanganui Regional Council (1998) - Regional Policy Statement for Manawatu-Wanganui

Hutt City Council (2003) - City of Lower Hutt District Plan

Invercargill City Council (2005) - Invercargill City District Plan

Kapiti Coast District Council (1999) - Kapiti Coast District Plan

Matamata-Piako District Council (2005) - Matamata-Piako District Plan

Porirua City Council (1999) - Porirua City District Plan

Rodney District Council (2003) - Omaha Coastal Compartment Management Plan

Rotorua District Council (1996) - Rotorua District Plan

Ruapehu District Council (2000,) - Ruapehu District Plan

Tauranga District Council (2006) - Tauranga District Plan

Timaru District Council (2005) - Timaru District Plan

Waikato District Council (1997) - Waikato District Plan

Wairoa District Council (2004) - Wairoa Coastal Strategy: Te Maahere Taatahi ki te Wairoa

Wellington City Council (2000) - Wellington City District Plan

Other References

www.arc.govt.nz - Auckland Regional Council website

www.ew.govt.nz - Environment Waikato website

www.gw.govt.nz - Greater Wellington website

Environment Waikato (1997a)

Environment Waikato (1997b)

Environment Waikato (1999a)

Environment Waikato (1999b)

Environment Waikato (1999c)

Environment Waikato (2002a)

Hastings District Council (2004)

Institute of Geological and Nuclear Sciences Ltd (2005)

Ministry for the Environment (2003b)

Tonkin and Taylor (2002a)

Tonkin and Taylor (1998)

Wellington Regional Council (2001)

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