Project Overview
Aqua Analytics was engaged to conduct a full condition assessment and leak-detection inspection of a critical trunk main in Sydney following a recorded pipe failure in May 2025.
The main, constructed from ageing cast iron, runs beneath an active railway corridor, making it one of the most difficult water assets in the network to inspect using conventional methods.
Using the AquaSnake in-pipe inspection platform which has a 1,000 meter tether, Aqua Analytics delivered a complete acoustic and CCTV condition assessment of the full pipe length under live operating pressure, with no service shutdown, no excavation, and no disruption to rail operations (or requirements to enter the rail corridor).
Inspecting a High-Risk, Inaccessible Trunk Main
This project presented a combination of challenges that are common across ageing water infrastructure networks, but rarely occur together at this scale:
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Criticality of supply:
The trunk main forms part of a critical water distribution network. Any inspection methodology requiring dewatering or service interruption would impact supply to a significant number of customers and was not operationally acceptable. -
Location beneath an active railway line:
The pipe's alignment beneath an active rail corridor made conventional access — whether through excavation, entry pits, or bypass infrastructure — either impractical or cost-prohibitive. Sections of the main had never been directly inspected. -
Ageing cast iron pipe:
Cast iron mains of this age are known to be susceptible to graphitisation, corrosion pitting, and progressive wall loss. Without an accurate internal condition assessment, the asset owner had no reliable basis for prioritising maintenance, rehabilitation, or replacement investment. -
Recent failure history:
A pipe failure event recorded in May 2025 elevated the urgency of the inspection and increased the risk profile of the asset. A reactive maintenance approach was no longer sufficient — the client needed comprehensive, evidenced condition data to inform forward planning.
The Solution — AquaSnake Live Insertion Inspection Platform
Aqua Analytics deployed the AquaSnake platform, a specialist in-pipe inspection tool designed for live, pressurised water mains.
AquaSnake is inserted through a standard access point and travels through the main under operating conditions, eliminating the need for dewatering or service interruption.
For this project, the AquaSnake platform was configured to deliver two simultaneous inspection methods across the full length of the trunk main:
Acoustic Leak Detection Inspection
The acoustic inspection module assessed the structural integrity of the cast iron pipe wall along the entire run. Acoustic-based inspection is particularly effective on metallic pipes, detecting areas of wall loss, corrosion, and internal deterioration that may not be visible to a camera. The data collected provides a quantitative condition profile that can be directly used for risk modelling and remaining service life assessment.
Live CCTV Water Main Inspection
Simultaneously, a high-definition CCTV survey captured a full visual record of the pipe’s internal condition including joint condition, lining integrity, corrosion patterns, encrustation, and any evidence of structural distress. The CCTV footage provides a permanent, auditable record of asset condition at the time of inspection.
Combined Dataset — Full-Length Coverage
By delivering both acoustic and CCTV inspection in a single deployment, Aqua Analytics provided the asset owner with a comprehensive, multi-method condition dataset covering the full pipe length, including the previously un-inspected sections beneath the railway corridor. No second mobilisation was required.
Why AquaSnake for Trunk Main Inspection?
AquaSnake is purpose-built for the inspection challenges that conventional methods cannot solve when it comes to larger diameter trunk water mains. It is the right tool when:
- The main cannot be taken out of service
- Access is restricted by railway lines, roads, buildings, or depth
- The pipe is cast iron, asbestos cement, or another legacy material at elevated risk of failure
- A full-length inspection is required, not just a spot check
- Both structural condition and visual data are needed to meet asset management obligations
- When the asset has limited access points for alternative surface-based acoustic technologies such as accelerometers or hydrophones
For water utilities and infrastructure owners managing ageing networks, live in-pipe inspection removes the single biggest barrier to condition knowledge: the cost and operational complexity of shutting down.
Work With Australia's Trunk Main Inspection Specialists
Aqua Analytics delivers trunk main inspection services across Sydney and nationally.
Our teams combine deep technical expertise with a practical, no-disruption approach. We are trusted by water utilities and asset owners to inspect assets that others can’t reach.
Get in touch to discuss your pipeline inspection and assessment requirements.
