Landslides and rockfalls

National parks are largely natural areas and can be inherently dangerous. Some natural geological features in parks, such as boulders, cliffs, steep mountains, caves or unstable landforms, may also be hazards. The National Parks and Wildlife Service’s priority in managing landslides and rockfalls in parks is to protect life and property, consistent as far as possible with conserving the natural and cultural values of parks.

Coastal cliffs at Curracarong in Royal National ParkWhat are landslides and rockfalls?

Landslides and rockfalls are the principal geological hazards (sometimes called geohazards) which may be a risk to park visitors, to workers (i.e. National Parks and Wildlife Service staff, contractors or volunteers) in parks, or to neighbouring landowners.

  • A landslide is the movement of a mass of rock, debris, or earth (soil) down a slope.
  • A rockfall is the action of boulders, rocks or slabs of rock falling or toppling.

Other geological hazards that may affect parks include areas of karst (caves formed from the erosion of soluble rocks such as limestone), mining subsidence, sinkholes, and earthquakes. Weather events such as heavy rainfall, flooding, temperature extremes or high winds can affect the stability of geological or geomorphological features in parks. Earthquakes may also destabilise geological features.

What is the difference between hazard and risk?

Hazard and risk are often used interchangeably, but in a risk management context they have quite different meanings.

A hazard is something that has the potential for doing harm or damage, e.g. a venomous snake, a slippery floor, an uncontrolled bushfire or an active volcano. A geological hazard can be an unstable part of the landscape, e.g. a steep hillside, loose or unsecured boulders or rocks, a fractured cliff or a rocky escarpment.

Risk is a conceptual construct for measuring how likely it is that a hazard will do harm or damage, and how severe the consequences will be.

In the context of landslides and rockfalls, a steep, unstable hillside may be a hazard. This hazard may pose multiple risks, such as the risk of a landslide impacting property, infrastructure assets or people, or the risk of damage from small rockfalls. The severity of each of these risks can be measured qualitatively (e.g. using a risk matrix to rate the risk on a scale from 'low' to 'extreme' by considering its likelihood and consequences), or quantitatively (e.g. using a risk formula to represent the risk as a number).

This policy is supported by detailed procedures

Implementation of this Policy is supported by National Parks and Wildlife Service (NPWS) Landslides and Rockfalls Procedures that provide more detailed guidance on how to record and respond to landslide and rockfall incidents and hazards in parks.

Principles

  1. NPWS has a duty of care to minimise the risk of landslides and rockfalls to people in parks and to neighbouring landholders.
  2. NPWS follows accepted risk management and safety practices; conforms with international and Australian standards; and follows corporate Risk Management Procedures and the Work, Health and Safety (WHS) System in its management of risk from landslides and rockfalls.
  3. NPWS bases the management of landslide and rockfall risks on:
    • the systematic identification of hazards
    • a realistic assessment of risks
    • consideration of a range of management options before making decisions, and
    • managing risks under the principle of ALARP (As Low As Reasonably Practicable), consistent with industry practice.
  4. NPWS gives priority, in its management of landslide and rockfall risks, to the protection of life, consistent as far as possible with the protection of the natural and cultural values of parks. The protection of property, including park infrastructure, is also an important consideration but is secondary to the protection of life.
  5. NPWS manages landslide and rockfall risks as part of its regular park management activities - that includes identifying, analysing, assessing and treating risks. NPWS obtains expert geotechnical advice on assessing landslide and rockfall risks where necessary.
  6. NPWS focuses its hazard identification efforts on more developed, high visitation or high-use areas in parks. NPWS treats and monitors hazards according to their assessed risk. Hazards with the highest assessed risk receive the greatest attention, followed by other hazards as resources permit.
  7. NPWS considers landslides and rockfalls as part of the assessment of planned construction and maintenance activities for park and visitor assets.
  8. NPWS maintains a record of identified landslides and rockfalls and management responses. NPWS will, over time, progressively identify and assess potential risks from landslides and rockfalls at a strategic level (i.e. across multiple locations in a park or several parks).
  9. NPWS assesses landslide and rockfall risks using a combination of qualitative and quantitative methods, and has adopted organisational thresholds for acceptable and tolerable risks.
  10. NPWS documents the process of assessing landslide and rockfall risks, determining a management response, and implementing the response.

Policy

NPWS minimises risks to visitors and workers in parks

  1. NPWS has a duty of care to park visitors and to people working in parks (i.e. NPWS staff, contractors or volunteers) to minimise the risks of landslides and rockfalls where:
    • the risk is foreseeable to NPWS
    • it is not insignificant
    • a reasonable person (if aware of the risk) would have taken precautions to limit or remove the risk.
  2. While exposure to landslides and rockfalls is a reality of working in outdoor areas, all NPWS employees are responsible for minimising risk to workers in parks, and must always look for options to achieve this outcome. This is consistent with the ALARP principle – to reduce risks to as low as reasonably practicable.

NPWS focuses its management of landslide and rockfall risks on high visitation areas

  1. NPWS recognises that many park visitors expect risks to be managed more intensively in high visitation locations than in more remote areas with no or minimally developed visitor facilities. Consequently, while the responsibility for safety in parks is always shared with visitors, NPWS will focus on high visitation locations in assessing and managing the risk to visitors from landslides and rockfalls.

NPWS takes reasonable measures to manage risks to neighbours

  1. NPWS has an obligation to take reasonable measures in response to landslides and rockfalls in a park that present a risk to neighbouring landholders. That obligation includes:
    • notifying landowners of the risk and allowing them into a park to assess the risk themselves
    • taking steps to manage the risk, including carrying out stabilisation works if that is the most effective option and subject to consideration of environmental impacts and availability of resources
    • seeking a reasonable contribution from neighbouring landholders to the cost of taking management actions that would benefit them.
  2. The extent of reasonable measures taken by NPWS to manage the risk of landslides and rockfalls to park visitors, to workers in parks, and to neighbouring landholders depends on:
    • seriousness of the risk
    • cost and difficulty of risk mitigation
    • feasibility of alternative management approaches
    • risk to workers treating the risk
    • relevant provisions of National Parks and Wildlife legislation
    • resources available to NPWS and landowners to deal with the problem.

NPWS is not obliged to warn visitors of obvious risks in parks

  1. Given the inherent dangers of natural areas and of some types of recreational activities, NPWS does not, in most circumstances, owe a duty of care to warn park visitors of an obvious risk. NPWS aims to inform park visitors where site-specific risks have been identified.

This policy supports NPWS meeting its duty of care

  1. Consistent implementation of this policy and the NPWS Landslides and Rockfalls Procedures will support NPWS meeting its duty of care and the legislative requirements for exclusion of personal liability. The National Parks and Wildlife Act 1974 (section 156C) excludes NPWS staff from personal liability for anything done or omitted to be done in good faith for the purpose of exercising functions under national parks legislation.

NPWS follows Australian standards and agency's risk and safety policies

  1. NPWS manages landslide and rockfall risks to life and property consistent with the Australian Risk Management Standard AS/NZS ISO 31000:2009, and under the agency's Enterprise Risk Management Policy, the agency's Risk Management Procedures, and the NPWS Visitor Safety Policy.
  2. The Enterprise Risk Management Policy requires NPWS to:
    • systematically identify, assess, treat and monitor risk in accordance with AS/NZS ISO 31000:2009 Risk Management
    • ensure that risks which could impact significantly upon the agency, life and property are assessed, monitored and reported upon
    • ensure staff have the necessary resources, tools and procedures to undertake their role in enterprise risk management and can identify and manage risks as part of any strategic, operational or project/program-based activities
    • ensure risk registers at the NPWS, branch and program level are developed and maintained for recording risks, related controls, treatment plans and accountabilities
    • review and report regularly on their risk management activity to monitor and review their risks, controls and risk treatment plans.

Industry standards guide this Policy

  1. NPWS follows existing industry standards and guidelines for managing geological hazards in implementing this policy and the accompanying NPWS Landslides and Rockfalls Procedures. Those standards and guidelines, adapted for a national parks context with the assistance of expert advice, are:
    • Landslide Risk Management Framework, published by the Australian Geomechanics Society in 2007 (AGS Guidelines)
    • Guidelines on Risk Assessment, published by the Australian National Committee on Large Dams in 2003 (ANCOLD Guidelines).

Staff are progressively trained in identifying landslide and rockfall hazards

  1. NPWS aims to provide targeted training for staff to assist in basic identification and understanding of potential landslide and rockfall hazards in parks.

Risk assessment is an integral management activity

  1. Assessment of landslide and rockfall risk is an essential consideration for maintaining or upgrading visitor facilities in parks, and for determining the location of new assets and facilities. NPWS follows Australian standards (where available) and applicable building codes for construction or upgrading of facilities. This may require an expert geological assessment to identify risks and treatment options.

NPWS considers several factors in managing landslide and rockfall risks

  1. NPWS will, in addition to assessing risk to life and property, consider other factors when determining how to manage landslide and rockfall risks:
    1. environmental impacts of alternative management responses (particularly impacts on biodiversity and cultural heritage)
    2. available resources, including funds and trained staff and management capacity to manage all risks (e.g. will it divert resources from another risk management activity?)
    3. impact of response on park management and use (e.g. will the response require the removal of a significant number of camping sites?)
    4. cumulative impact of responses that may occur over time and across visitor areas, parks and branches
    5. relevant plans or standards
    6. community views and expectations (including on extent of modifications to a location).

Management responses to identified hazards must be implemented

  1. It is critical that once a geological hazard has been identified and an appropriate management response has been determined, that the response is implemented.

Qualitative risk assessments are done for all landslide and rockfall hazards

  1. NPWS will firstly do a qualitative risk assessment of a landslide or rockfall hazard using the standard risk matrix, which compares likelihood and consequence. The qualitative assessment will result in a rating of low, medium, high or extreme risk.

Quantitative risk assessments are mandatory for extreme risks and before construction

  1. If the qualitative assessment results in an extreme risk, NPWS must:
    • stop any at-risk activity
    • make the location safe
    • obtain a quantitative risk assessment.
  2. If the qualitative assessment results in a high risk, NPWS will also generally obtain a quantitative risk assessment, even though the risk matrix does not mandate that.
  3. NPWS must do a quantitative risk assessment for construction activities in areas susceptible to landslides or rockfalls.

Quantitative risk assessments are done by qualified geotechnical experts

  1. Where a quantitative risk assessment is required – i.e. mandatory for extreme risks and for construction activities in geohazard susceptible areas, and highly recommended (although not mandatory) for high risks – NPWS will engage a suitably qualified and experienced person to prepare the risk assessment consistent with the NPWS Guidelines for Quantitative Risk to Life Calculations for Landslides (NPWS QR Guidelines).
  1. A quantitative risk assessment will result in a landslide or rockfall hazard falling into one of three risk categories – an acceptable, tolerable or unacceptable risk. A risk threshold is a numerical description (e.g. 1 in 1 million or 1 in 100,000) of the upper limit of a risk category – i.e. there are different thresholds (upper limits) for acceptable risk and for tolerable risk.
  2. Risks rated higher than the tolerable risk threshold are unacceptable.
  3. Consistent with the AGS Guidelines, NPWS has adopted thresholds for acceptable and tolerable risks. These thresholds are detailed in the NPWS Landslides and Rockfalls Procedures.
  4. The tolerability of a risk may also be influenced by:
    • the ALARP principle – risks should be managed to be As Low As Reasonably Practicable
    • the relative level of modification of the area in which the hazard is located (e.g. a highly constructed visitor area compared to a largely natural setting)
    • visitor and staff exposure to the hazard (e.g. areas with high visitation and staff activity compared to low-visitation locations)
    • the type of experience visitors seek in the vicinity of the hazard (e.g. picnicking or sight-seeing compared to rock-climbing or remote area bushwalking).
  1. As an integral part of managing landslide and rockfall incidents in parks, NPWS will:
    • record incidents in the appropriate corporate systems
    • follow agency procedures to report safety incidents where a person is exposed to a serious risk, or where a serious injury or death has occurred
    • identify incidents that require treatment to address risks to safety or property
    • record and track actions for hazards requiring treatment, including any necessary physical works and/or ongoing monitoring, in asset management systems.
  2. The NPWS Landslides and Rockfalls Procedures provide more information on steps to be followed in responding to landslide and rockfall incidents.
  1. When NPWS, or an external proponent, is planning to undertake construction or maintenance works in an area of known or potential landslide and/or rockfall risk, NPWS will manage the risk by:
    • considering the risk as part of the environmental impact assessment process (i.e. through a Review of Environmental Factors or CRA) – this may include an expert geotechnical assessment
    • obtaining, where required by the NPWS Construction Assessment Procedures, appropriate engineering assessment and certification:
      • prior to works commencing
      • during the works ('hold points' to allow for inspection)
      • at the conclusion of works.
  2. When maintaining and upgrading existing visitor facilities in parks, NPWS will, consistent with the NPWS Quantitative Risk Guidelines and industry standards, tolerate a higher level of risk than for construction of new facilities or for major redevelopment of existing facilities.
  3. When constructing new visitor facilities or for major redevelopment of existing facilities in parks, NPWS will, consistent with the NPWS Quantitative Risk Guidelines and industry standards, tolerate a lower level of risk than for existing visitor facilities. Building new facilities allows NPWS to adopt higher construction and safety standards.
  4. The NPWS Landslides and Rockfalls Procedures provide more information on steps to be followed when planning new works or maintenance activities.
  1. NPWS aims, over time, to develop and implement approaches to support the strategic identification and assessment of landslide and rockfall risks. This will progressively enable park managers to consider up-front the relative risks across a whole park or over multiple parks.
  2. Strategic assessments will enable improved decision-making about resource allocation and risk management at a landscape scale, to complement ongoing management of landslide and rockfall incidents.
  3. The NPWS Landslides and Rockfalls Procedures provide more information on steps to be followed in moving towards implementing a strategic approach to managing landslides and rockfalls.

Policy adopted 30 November 2019.

Scope and application

This policy applies to all lands acquired or reserved under the National Parks and Wildlife Act 1974 (NPW Act) except for lands reserved under Part 4A of the Act (unless the Board of Management for those lands has adopted the policy). However, NPWS staff can use the policy as guidance in their dealings with Boards of Management.

This policy applies to landslides and rockfalls occurring on the surface of karst areas in parks, and to rockfalls inside caves. The NPWS Caves Access Policy addresses visitation to caves.

This policy applies to landslides and rockfalls in parks caused by mining subsidence. Hazards associated with mining subsidence may also be addressed through separate whole-of-government processes, consistent with the Enterprise Risk Management Policy and Procedures and the NPWS Visitor Safety Policy.

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This policy does not apply to development proposals in alpine resort areas in Kosciuszko National Park, which are covered by State Environmental Planning Policy (Kosciuszko National Park-Alpine Resorts) 2007 (Alpine SEPP). The Alpine SEPP requires geotechnical and land stability issues associated with construction in steep alpine environments to be rigorously assessed under the Geotechnical Policy – Kosciuszko Alpine Resorts (2003) (PDF 429KB).

The NPWS Landslides and Rockfalls Procedures provide further information to support the implementation of this policy.

Objectives

This policy aims to:

  • provide clear guidelines for NPWS's management of landslides and rockfalls in parks
  • explain NPWS's duty of care, in its management of landslides and rockfalls, to park visitors and to staff and contractors working in parks, and to owners of land adjoining parks
  • ensure that NPWS responsibly manages landslides and rockfalls in parks while also protecting the natural and cultural values of parks and providing opportunities for people to experience and appreciate parks.

Definitions

Acceptable risk means a risk which society is prepared to accept – additional work to further reduce the risk is generally not justifiable (AGS Guidelines).

AGS Guidelines means the Landslide Risk Management Framework published by the Australian Geomechanics Society in 2007. The Framework addresses landslide susceptibility, hazard and risk zoning for land use planning, and outlines a step-by-step process for doing risk analysis, risk assessment and risk management of landslide and rockfall hazards.

ALARP means as low as reasonably practicable – the ALARP principle states that 'risks, lower than the limit of tolerability, are tolerable only if risk reduction is impracticable or if its cost is grossly disproportionate (depending on the level of risk) to the improvement gained.' (ANCOLD Guidelines).

Alpine resort areas means the Thredbo, Perisher Range, Mount Selwyn and Charlotte Pass ski resorts; the Kosciusko Mountain Retreat, Ski Rider and Sponar's Chalet accommodation areas; and the Bullocks Flat Skitube terminal.

ANCOLD Guidelines means the Guidelines on Risk Assessment published by the Australian National Committee on Large Dams in 2003. These guidelines are an accepted industry standard for the practical application of risk assessment, including guidance on addressing societal risk.

Consequence means the outcome or impact of an event and may be expressed qualitatively or quantitatively – there can be more than one consequence from one event (AS/NZS 31000:2009 Risk Management).

Geohazard means a geological or geomorphological process that poses a threat to people and/or their property – the principal geohazards in NSW parks are landslides and rockfalls.

Geotechnical engineer (or engineering geologist) means a specialist geotechnical engineer or engineering geologist who is degree-qualified, is a member of a professional institute and who has achieved chartered professional status as a CPEng, CPGeo or RPGeo with 'Landslide Risk Management' as a core competence (adapted from: NSW Department of Planning 2003 – Geotechnical Policy: Kosciuszko Alpine Resorts).

Geotechnical report means a report prepared by and/or technically verified by a geotechnical engineer or engineering geologist of an assessment of the risk posed to people or property by all reasonably identifiable hazards at a site (adapted from NSW Department of Planning 2003 – Geotechnical Policy: Kosciuszko Alpine Resorts).

Hazard means a potential or existing condition that may cause harm to people or damage to property or the environment (Emergency Management Australia 1998 – Australian Emergency Management Glossary). In this policy, a hazard is a physical event or condition in the landscape that causes or may cause harm or damage e.g. a landslide or a rockfall.

Karst means an area or environment formed from the erosion of soluble rocks such as limestone to create underground caves and streams, fissures and sinkholes.

Landslide (or landslip) means the movement of a mass of rock, debris, or earth (soil) down a slope (AGS Guidelines).

Likelihood means a general description of probability or frequency – it can be expressed qualitatively or quantitatively (AS/NZS 31000:2009 Risk Management).

Mining subsidence means changes in the landscape resulting from previous or continuing sub-surface mining in parks, which may cause the collapse of cliffs, changes to the ground surface and to drainage, and other risks to park visitors and staff.

NPWS QR Guidelines means the NPWS Guidelines for Quantitative Risk to Life Calculations for Landslides prepared by Golder Associates in 2019. NPWS requires geotechnical consultants to use these guidelines when doing quantitative risk assessments of rockfall and landslide hazards in parks.

Park means a reserve gazetted under the National Parks and Wildlife Act 1974, including a national park, nature reserve, historic site, Aboriginal area, state conservation area, karst conservation reserve, regional park or any land acquired by the Minister under Part 11 of the Act.

Qualitative risk assessment (or analysis) means an analysis which uses a descriptive [e.g. low, high or very high] or numeric rating scale to describe the magnitude of potential consequences and the likelihood that those consequences will occur (AGS Guidelines).

Quantitative risk assessment (or analysis) means an analysis based on numerical values of the probability, vulnerability and consequences [of the risk], and resulting in a numerical value of the risk (AGS Guidelines). It is often expressed as a ratio, e.g. 1:10,000.

Risk means a measure of the probability and severity of an adverse effect to health, property or the environment (AGS Guidelines). Risk is often expressed as a combination of the likelihood of an event's occurrence and its consequences (AS/NZS ISO 31000:2009 ‐ Risk Management).

Risk threshold means a numerical description (e.g. 1 in 1 million or 1 in 100,000) of the upper limit of a risk category – i.e. there is a threshold (upper limit) for an acceptable risk, and a threshold (upper limit) for a tolerable risk.

Rockfall means the action of boulders, rocks or slabs of rock falling or toppling.

Tolerable risk means a risk within a range that society can live with to secure certain net benefits – the risk is non-negligible and should be kept under review and reduced further if possible (AGS Guidelines).

Accountabilities

See the NPWS Landslides and Rockfalls Procedures for all accountabilities.