Bakers Hill Subsurface Utility Survey - Subtera Subsurface Locating

ClientMain Roads Western AustraliaLocationAustralia, WA

The Challenge

The task was to map all the subsurface utilities in Bakers Hill, WA – not a small undertaking! Main Roads WA needed this accurate information on the subsurface utilities in Bakers Hill WA to complete their design of a new road, in various formats, including from 12d Model.

Civil designers need their designs to work in the real world, and existing underground infrastructure can cause major issues. The existing records for the asset owners can be accessed through Dial Before You Dig (DBYD), but the spatial accuracy of these records is often not precise enough – in general there is a lot more underground than these records indicate, and the designers need data they can trust…enter subsurface utility locaters.


The Solution

Dale Shearsmith’s team proceeded to locate all known Quality D utilities via Ground Penetrating Radar (GPR) and electromagnetic locaters. They then potholed for Quality Level A data.

SUI AS5488 (Classification of Subsurface Utility Information)

This Standard was prepared by Standards Australia Committee IT-036. The objective of this Standard is to provide utility owners, operators and locators with a framework for the consistent classification of information concerning subsurface utilities.

This Standard is intended to be used by those agencies and organisations that own, operate or regulate subsurface utility infrastructure and those that collect, depict and map such infrastructure. This Standard is also intended to be used by developers and consent authorities involved in the planning, approval and installation of subsurface utility infrastructure.

Subtera Methodology

To provide consistent data across projects, Subtera uses the following methodology

  • Take Quality Level C & D data and validate it to Quality Level A & B
  • Collate “As Constructed” drawings of the subsurface infrastructure
  • Ensure these utilities are located and surveyed
  • Search for “Unknown” subsurface utilities at the final stage
  • Every “Known” and “Unknown” utility will be accounted for in our field report providing an audit trail
  • We adhere to all asset owners regulations when accessing manholes and infrastructure and hold accreditions for ATCO High Pressure Gas, Telstra Fibre and the Watercorp
  • All works are carried out with a focus on Zero Harm to our employees and the public as outlined in our HSSE documentation


The Result

By delivering data to the AS5488 standard, the team was able to qualify the data with attributes, which flow through the design process, allowing Main Roads to accurately budget for asset relocations as well as trust the clash detections listed and integrate some of the utilities that were already there, allowing for more saving of money.


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