RAVEN QUAY 3 WATERS RENEWAL, KAIAPOI

PROJECT OVERVIEW

Ongrade Drainage & Excavation was engaged by Waimakariri District Council to deliver the Raven Quay 3 Waters Renewals project within the road reserve of Raven Quay, Kaiapoi. The works involved the renewal and construction of critical wastewater, stormwater, and potable water infrastructure in a constrained urban environment, adjacent to the Kaiapoi River, heritage features, and active businesses.

Project Scope
Construction of four 3 Waters services within the Raven Quay road corridor, comprising a rising sewer main, gravity sewer main, potable water main, and stormwater main.

Wastewater

Installation of approximately 100m of DN225 gravity sewer main, installed at depths of up to 4.0m, including tie-ins to existing live infrastructure.
Wastewater works undertaken on live sewer networks, including both gravity and pressure systems, requiring careful sequencing and temporary service management.
Pressure sewer pipework installed via directional drilling, undertaken to accelerate construction and significantly reduce traffic management requirements and disruption to the public.
Installation of sheet piling to depths of up to 8.0m to support deep gravity wastewater excavations, combined with extensive dewatering to manage groundwater and maintain safe working conditions.
Wastewater excavation supported by ballast rafting beneath the sewer pipeline, providing stability in poor ground and high groundwater conditions.

Stormwater

Installation of a new stormwater main to the Kaiapoi River, comprising approximately 40m of large-diameter concrete pipe (DN300–DN375), including outfall works.
Stormwater outfall works completed within tidal working windows, requiring careful programming and implementation of robust erosion and sediment control measures to protect the river environment.
Stormwater pipework directionally drilled beneath the Kaiapoi War Memorial and through the river stopbank, avoiding disturbance to a significant heritage structure and critical flood protection assets.
Stormwater pipe sections were floated downstream and positioned into final alignment, providing an efficient and innovative installation methodology within the river environment.
Extensive ground settlement monitoring undertaken around the Kaiapoi War Memorial following drilling works, confirming ground stability and protecting the integrity of the monument.

Potable Water

Installation of approximately 140m of potable water main, together with associated connections and fittings.

General / Enabling Works

Completion of dilapidation surveys, along with proactive communication with local businesses, residents, and stakeholders throughout the works.
Delivery of comprehensive traffic management, maintaining access and safety within a busy urban environment.

Associated Civil Works

Road construction and reinstatement works following underground service installation.
Footpath construction and rebuilds, including reinstatement of pedestrian infrastructure.
New kerb and channel preparation and pouring, integrated with final surfacing works.
Coordination and management of asphalt surfacing crews.
Installation of street furniture and reinstatement of road corridor berms, including topsoiling and hydroseeding.

Project Delivery

All QA specifications were completed, with documentation provided to the Engineer.
Nil non-conformances were recorded, and a high-quality outcome was achieved.
An Environmental Management Plan was successfully implemented, with no environmental incidents recorded.
Ongrade maintained a strong working relationship with Waimakariri District Council and was commended by stakeholders for communication, site management, and workmanship