Wastney Terrace Stormwater Upgrade

Protecting homes. Respecting neighbours.

Project Overview

Client Nelson City Council

Location Wastney Terrace, Marybank, Nelson

Service Stormwater Infrastructure

Project Value $1.87M

Duration April 2022 – July 2023

Completed 2023

• At a Glance

  • 530m reinforced concrete stormwater network

  • Constructed through private property and steep terrain

  • 21 manholes and two high-capacity sumps

  • Deep excavations with temporary structural support

  • Additional works delivered through collaborative procurement

  • Zero Lost Time Injuries (LTIs)

• The Challenge

  The Wastney Terrace Stormwater Upgrade was designed to improve flood resilience for the Marybank community by constructing a new stormwater network through steep terrain, private driveways and residential properties before discharging to the coast.

  The project required more than technical capability. A new 530-metre reinforced concrete pipeline, incorporating 21 manholes and high-capacity stormwater structures, had to be installed while relocating existing water and wastewater services and working within metres of occupied homes. Every stage of construction demanded careful planning to protect private property, existing structures and the relationships that would ultimately determine the project's success.

  The project presented far more than a conventional pipeline installation. The proposed alignment crossed an operational school, a former landfill site, busy public roads, recreational facilities and existing underground services. The original construction methodology also relied on long directional drill installations, introducing significant technical, financial and programme risk before construction had even begun.

• What Mattered

  For many residents, construction wasn't taking place outside their property—it was happening through it.

  Maintaining access, protecting homes and communicating openly with landowners became just as important as installing the new infrastructure. The project also presented significant environmental challenges, with steep topography, deep excavations and severe weather events requiring robust erosion and sediment controls throughout construction. Success depended on earning trust as much as delivering engineering excellence.

• Our Approach

  Tasman Civil worked closely with Nelson City Council throughout an extensive direct procurement process, helping refine multiple design iterations before construction commenced. That collaborative approach continued on site, allowing the team to respond confidently as additional work packages were introduced and project priorities evolved.

  Technically, the project required deep excavations, groundwater management and temporary support systems to safely construct new stormwater infrastructure immediately beside existing homes and structures. Careful engineering assessments, structural monitoring and tailored construction methodologies ensured neighbouring buildings remained stable throughout the works, despite excavation occurring within close proximity to occupied dwellings.

  Equally important was the team's commitment to stakeholder relationships. Regular communication, respectful engagement and practical problem solving helped build strong relationships with residents, landowners and neighbouring property owners. That trust not only contributed to a successful project outcome but also led to new opportunities beyond the contract itself.

• The Outcome

  The completed stormwater network provides greater resilience for the Marybank community, reducing flood risk while delivering modern infrastructure designed to support the area's future.

  Completed safely and below the client's original budget expectations, the project also earned positive feedback from residents and property owners for the way the works were managed. It stands as an example of Tasman Civil's belief that successful infrastructure projects are measured not only by the assets delivered, but by the relationships built throughout the journey.

• Capabilities Demonstrated

  • Stormwater Infrastructure

  • Deep Excavations

  • Reinforced Concrete Pipelines

  • Temporary Works

  • Structural Support Systems

  • Service Relocations

  • Erosion & Sediment Control

  • Stakeholder & Landowner Engagement

  • Collaborative Contract Delivery

  • Quality Assurance

  • Environmental Management