Client: March Cato
Location: Rosedale, Auckland
Service: Full utility locating, mapping, and manhole documentation
Technologies Used: EML, 2D GPR, 3D GPR (Stream DP), RTK GPS survey, CAD outputs, 360° manhole imaging
Ground Scan NZ was engaged by March Cato to support the early stages of an upgraded wastewater rising main project extending from the Rosedale Pump Station. With the alignment running through a heavily serviced corridor, the primary objective was to accurately identify, verify, and map all utilities that could influence design, construction, and future risk management.
To achieve a high-confidence dataset, our team deployed a combination of complementary locating technologies. Electromagnetic Locating (EML) was used as the initial method to trace conductive assets and establish baseline positions. This was supported by extensive 2D Ground Penetrating Radar sweeps, enabling us to detect non-conductive utilities and refine depth assessments. For complex areas and multi-layered subsurface conditions, advanced multi-channel (3D) GPR technology was utilised, providing high-resolution volumetric data and enhanced clarity where traditional methods alone may fall short.
All findings were captured using RTK GPS for survey-grade spatial accuracy, allowing March Cato to integrate the results seamlessly into their design workflows. The final deliverables were supplied in CAD format, ensuring compatibility with engineering platforms and enabling efficient planning for the rising main upgrade.
In addition to utility locating, Ground Scan NZ completed internal manhole inspections to support the broader assessment of existing wastewater assets. Each manhole was documented with interactive 360° imagery, giving the project team a virtual view of internal conditions without the need for repeat physical access—improving both safety and efficiency.
The combination of advanced subsurface investigation, high-precision survey, and immersive visual documentation provided March Cato with a robust, dependable dataset. This work ensures the upcoming wastewater rising main upgrade can progress with reduced uncertainty, improved design accuracy, and greater confidence in the subsurface environment.
