Asset Protection

Asset Protection

Working Near Busselton Water Assets

Work that requires approval

In accordance with the Water Services Act 2012, approval is required when you’re planning to work inside the prescribed proximity (distance from the asset) for the size and type of asset tabulated in Table 1. Damage can be avoided by carefully planning and conducting your work.

The information provided in this document is to be used as a guide only. It does not remove the responsibility from the excavator/ contractor to physically locate all services prior to excavation/ ground-disturbing works.

Note: The use of the words “pipeline” and “asset” in this document includes all pipes, fittings, services and associated materials.

Type of WorkAsset SizePrescribed Proximity
Ground disturbing works
Includes heavy vehicle movement, ground compaction, dewatering, earthworks, open and trenchless excavations
AC pipeline of all diameters
< 250 mm diameter pipeline
4 m
Ground disturbing works
Includes heavy vehicle movement, ground compaction, dewatering, earthworks, open and trenchless excavations
≥ 250 mm diameter pipeline6 m
Buildings, structures, and other obstructions
Includes residential/commercial/industrial buildings, pools, sheds, carports, transport infrastructure, services, equipment installed on our assets, stockpiles, ground anchors, large trees.
All Pipelines10m on both sides of the asset
15m above & below the asset
Pile DrivingAll Pipelines100 m
BlastingAll Pipelines1,000 m

Prescribed Proximity

Approval Process

The steps below outline the process for working safely near our assets:

Dial Before You Dig: Submit a Dial Before You Dig (DBYD) enquiry to determine the approximate location of our assets.

Early Engagement: If you are planning to work within our pipelines’ prescribed proximity, please contact Busselton Water as early as possible during the design phase.

Potholing: The location, depth and direction of all assets near your work must be confirmed using potholing. This must be undertaken with reference to DBYD plans and other information we provide. You can engage, at your cost, independent location services to undertake potholing work for you.

Risk Assessment: Conduct a damage risk assessment based on the potholing based on the below questionnaire.

Will the site work
Cause direct contact in any way with a pipeline (including any relatively minor contact with the protective coating)?
Involve digging adjacent to or otherwise disturbing pipeline foundations, bedding or other support?
Cause subsidence of a pipeline, supporting material or structures?
Cause high loads to be applied directly to a pipeline or the soil above it?
Result in high impacts, shock or vibration near or directly to a pipeline?
Cause electrical currents to be directly applied to or induced in a pipeline?
Limit access to a pipeline or other assets for future works or maintenance?

Alternative Analysis: If your work presents a risk, consider what options are available to reduce these risks to allow the work to be carried out safely. We recommend you consider the following options to reduce the risk of potential damage.

Alternative Analysis
Redesign your work
• The preferred option is for you to redesign your work to be outside the Prescribed Proximity to our asset
Relocate, Replace or Reconfigure our asset
• Where you are not able to redesigned, our assets may be able to be relocated, replaced or reconfigured
• Designs must be completed by a suitably qualified practicing design or consulting engineer acceptable to Busselton Water
Protect our asset• Where the above options are not feasible, we may allow you to work within our Prescribed Proximity if you adequately protect our assets
• Proposed protection works shall be designed by a suitably qualified practicing design or consulting engineer acceptable to Busselton Water

Request Approval: Request approval from Busselton Water for the work and provide options after alternative analysis.

Busselton Water Assessment: Proposed works will be assessed with consideration to future demand requirements, in which case we may require pipelines to be replaced or increased in size or strength.

Costs: You are required to pay all costs associated with the proposal however Busselton Water may contribute part of the cost, depending on details and timing of the proposal.

Undertaking Works: You may be given approval to undertake the works to Busselton Water requirements. In these circumstances some costs will be required to be paid in advance for our assessment and approval through to completion. Alternatively, Busselton Water may undertake all or part of the works provided quoted costs are paid in advance.

Construction Activities Requirement: The construction activities shall follow the requirements as below.

WorkPotential Impact on AssetsRequirement
VibrationsCommon types of work that generate excessive vibrations include:

• vibratory ground compaction
• movement of heavy vehicles
• blasting
• demolition works
• pile driving and boring.

Excessive vibrations can cause direct damage to our assets, such as damage of pipe joints or cracking of brittle pipes (AC, RC and CI), or can cause soil subsidence resulting in the collapse of our assets.
Work that creates excessive vibrations within the Prescribed Proximities to our assets may be considered subject to the following requirements:

a) Where possible, use low vibration work methods and control vibration at the source, including:

• The use of light rollers, plate compactors and tampers over the use of heavy vibratory rollers is preferred
• The use of static compaction equipment over vibratory compaction equipment.
• Working in shallower layers.

b) During significant vibratory works, we may require you to:
• perform an asset condition assessment prior to work
• undertake prior testing of vibrations to establish safe limits for the specific conditions of the work
• undertake continuous monitoring of vibrations and asset condition during the work and adhere to safe vibrations limits (peak particle velocities), which we may specify for a particular asset
ExcavationExcavations of all types can cause damage from excavation equipment directly impacting our assets or may affect the stability of our assets by undermining the assets bedding and support material.

The risk of damage increases with more extensive excavations and larger machinery, or for excavations near brittle pipe materials which can be more easily damaged.

AC, RC and VC pipelines are assembled from short pipe lengths. Any differential soil movement can damage these joints causing a leak or burst.
Open excavations within the Prescribed Proximities of our assets will be considered subject to the following requirements:

a) Any deep excavation (i.e. deeper than the asset or 1200mm, whichever is the lesser) where its zone of influence passes under the asset is required to have a ground support system such as shoring in use. Serious consideration should also be given to temporarily taking the asset offline during the works to prevent any possible inundation.

When shoring is installed, it is a requirement to ensure that no ground movement/subsidence occurs on removal, particularly in the proximity of AC, RC & VC mains.

If the main is to be taken offline, the following applies:

a) The main is to be depressurised during the duration of the works, by isolation or temporarily cutting and capping the main on either side of the excavation, in an area outside of the zone of influence of the excavation.
b) Depending on the specific location, a temporary bypass main and temporary services may be required.

c) Buried assets must not be exposed; adequate cover (mentioned in Table 4) is maintained at all times, including during road box-out – though a minimal exposure is acceptable, such as for service crossings and if only the top of the pipeline is exposed or where the actual cover has to be established. Establishment of actual cover is to be carried out prior to the works commencing via potholing, preferably by vacuum excavation techniques

d) Thrust blocks restrain thrust forces in pressurised pipelines and are commonly found at pipeline fittings and changes in pipeline size and direction – thrust blocks and the ground supporting them should never be disturbed as this could cause sudden failure of the asset.

e) Excavation of acid sulphate soils can cause damage to assets through corrosion, in particular steel pipelines – we may require you to address the risks and management controls to our assets in your acid sulphate soils management plan.

f) Details of proposed work methods (including excavation equipment) and details of any assets that need to be exposed must be provided.

g) Backfilling and reinstatement – our pipelines are installed in compacted bedding, selected fill and support material which is part of the pipeline design. Where pipelines are exposed, we require you to backfill and reinstate the pipeline to our standards.

h) We may require an inspection by one of our representatives before backfilling takes place and may require compaction test results.
DewateringDewatering (the removal of groundwater from a construction site) has the potential to cause ground
Subsidence which may affect the stability of buried assets.
Dewatering or alteration of the water table within the Prescribed Proximities to our assets (as defined in Table 1) may be considered if you can demonstrate that there will be no impact on our assets.

Generally, we require you to address the risks to our assets in a dewatering management plan which should include information about:

a) purpose of dewatering (an explanation of why dewatering is necessary)
b) dewatering technique (including wellpoint, deep well, open hole)
c) anticipated dewatering flow rate and total dewatering duration
d) measures and techniques to manage geotechnical stability issues
e) contingency plans in case of any emergency situation.
Movement of heavy vehiclesHeavy vehicles, such as construction equipment or other heavy transport, crossing buried assets can cause damage due to heavy loads and vibration.

Even relatively light loads can crack assets if the asset is brittle with shallow cover RC, AC, VC and CI pipelines are particularly susceptible to damage from the movement of heavy vehicles.
Movement of heavy vehicles (other than on permanent roads) within the Prescribed Proximities of our assets (as defined in Table 1) may be considered subject to the following requirements:

a) You must confirm the depth of cover above an asset with potholing. Subject to having minimum cover for trafficable conditions, vehicles that are legally permitted on public roads are allowed within the Prescribed Proximities.
b) For heavy construction plant or vehicles that exceed maximum legal load limits (such as piling rigs, cranes and rollers), you may need to provide an engineering assessment demonstrating that there will be no excessive loadings or vibrations on our assets. The assessment should take into consideration the condition of our asset, which you may choose to confirm via an asset condition assessment.
c) The use of protective measures such as increased ground cover above the asset or steel road plates may be permitted where no other viable options are available.

Minimum Cover Requirements

The minimum cover (depth from ground level to top of pipe) requirement must always be achieved, defined in Table 4, as the minimum cover provides support and protection from excessive loads and damage.

Type of Asset LocationCover
≥ 250 mm diameter pipelineRoad reserves, car parks and other trafficable areas

Parklands, private property and other non-trafficable areas
1,000 mm

600 mm
< 250 mm diameter pipelineRoad reserves, car parks and other trafficable areas

Parklands, private property and other non-trafficable areas
600 mm

600 mm
Residential service connectionsRoad reserves, car parks and other trafficable areas

Parklands, private property and other non-trafficable areas
450 mm

450 mm

Work that does not require approval

  • Lightweight structures, fencing and walls that can be readily removed
  • Planting and removing trees that have a mature height of less than 5 m