Following the Auckland Anniversary Day floods, Kerry Drainage & Civil delivered emergency stormwater and stream remediation works at Te Auaunga / Oakley Creek, restoring damaged infrastructure, stabilising the stream banks and helping reopen Great North Road to four lanes of traffic.
Severe floodwaters had scoured the embankment at Waterview Reserve approximately 3.5m below road level, undermining a city-bound traffic lane and destroying two stormwater outlets. With unstable ground, exposed high-voltage power cables and a sensitive creek and estuary environment, the project required an urgent response and a carefully coordinated engineering solution.
Engaged by Auckland Council Healthy Waters under an existing Emergency Works Contract, KDCivil acted as main contractor, managing the project from initial site stabilisation and investigations through to design coordination, construction and reinstatement.
Engineering a solution under pressure
Working alongside Auckland Transport, Vector and the Waterview Tunnel stakeholders, KDCivil prioritised protecting critical power infrastructure and supporting the rapid reopening of Great North Road, while developing a permanent solution for the damaged stormwater network.
The works included constructing temporary stormwater diversions, building a new gravity retaining wall to support the road, reconstructing two stormwater outlets, and reinstating rock armouring and scour protection. The team also stabilised the slopes, completed planting and reinstated the public reserve.
With constrained access, unstable rip-rap, undermined trees, live stormwater flows and exposed 11kV and 22kV power cables, careful planning and coordination were essential throughout construction.
Delivering value through practical problem-solving
Kerry Drainage & Civil delivered worked closely with the client and other stakeholders to resolve design and construction challenges as they arose. By selecting readily available materials, coordinating specialist utility works and reusing suitable materials and assets, the team reduced procurement delays, waste and overall project costs.
Hardstand material was sourced from another worksite, existing rip-rap was reused, and temporary manholes and outfall pipes were recovered from storage or other projects. The team also retrieved assets at low tide without tracking machinery into the waterway, helping minimise environmental impacts.
The project was completed for $530,000 against an initial estimate of $750,000, demonstrating the value of practical construction planning and resourceful delivery without compromising the quality of the permanent works.
A lasting solution
The completed works restored the stormwater outlets, stabilised the damaged embankment and provided a resilient solution for the surrounding road and waterway. Rather than relying on temporary repairs followed by a separate permanent construction phase, KDCivil delivered a lasting solution that addressed the immediate emergency and the longer-term infrastructure requirements.
Healthy Waters Project Manager Jack Thompson praised the team’s collaborative approach, design input and ability to balance the competing needs of the road network, power infrastructure and sensitive environment. The client was particularly pleased that the project delivered a structurally sound and visually appealing result under challenging emergency conditions.
The project was a finalist in the 2023 CCNZ Construction Awards, recognising the team’s delivery of a complex emergency infrastructure project.
