Between 2019 and 2021 Wellington Water experienced a run of significant failures on critical water assets. Beyond the immediate, often expensive cost of urgent repairs, these incidents inconvenienced the public and eroded confidence in the reliable supply of drinking water and the effective treatment of wastewater and stormwater. Wellington Water responded with the Very High Critical Assets (VHCA) condition assessment programme, which ProjectMax supported. By the time it completed in 2024, Wellington Water understood the condition of almost 500 km of its most critical assets.

Wellington Water then recognised it needed the same picture of its remaining underground network, and that condition assessment needed to become a business-as-usual activity rather than a one-off response to failure.

The Linear Assets Condition Assessment Programme (LCAP) applied the lessons from VHCA:

• A more pragmatic approach to expensive, technology-heavy pressure pipe inspections, using existing data or efficient data collection to justify deploying the costlier technology only where it was warranted. This is the approach set out in the Water New Zealand Pressure Pipe Manual, published in 2025, which ProjectMax authored.
• More thorough planning of both gravity and pressure inspections, so the right pipes were inspected with the right technology, and network access and traffic management were arranged before crews mobilised in the field.
• A programme management approach that packaged nearby inspections together to improve the inspection contractor’s efficiency.
• A condition assessment confidence grading system, based on national guidance, to signal where more information was needed before choosing an intervention.

LCAP now runs as a business-as-usual activity and is becoming more efficient as the lessons bed in. Wellington Water has recovered from the earlier critical failures and, more importantly, now has a strategy to reduce and prevent them, along with a clearer view of the investment required. The community has a more reliable drinking water supply, and wastewater is not ending up where it should not. The programme is ongoing.