Mangatawa Bridge Repairs
In March 2025, Pryde Contracting was engaged to complete essential stream and roading infrastructure works at Mangatawa Stream. This project was critical for stabilising the stream banks, protecting key structures from erosion, and ensuring the longevity of crucial culvert and manhole infrastructure following a period of persistent, heavy regional rainfall.
As subcontractors to the Principal Contractor (QRS), our scope of work involved:
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Carrying out earthworks on the stream embankments.
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Constructing robust rip rap protection through the stream, up the banks, and around the bridge abutments.
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Installing a new manhole and associated culvert structures.
Extreme Conditions Demand Adaptation
This job was executed during challenging conditions, forcing our team to apply adaptive project management and execution strategies:
Ground Instability & Timeline Interruption: The consistent winter rain led to a significant water table and subsidence problems in the ground. This necessitated an interrupted timeline, requiring the team to shift from linear work to a concurrent methodology to ensure continuous progress.
Logistical Constraints: Due to highly restricted space for aggregate laydown on site, the required rip rap rock had to be stored offsite. This demanded intricate just-in-time delivery coordination, bringing the rock in only as needed for immediate placement.
River Diversion & Access: The necessity of working within the active stream required implementing a river diversion. This mandated the use of delicate Standard Operating Procedures (SOPs) on site, and close collaboration with HBRC (Hawke's Bay Regional Council) regarding the necessary resource consent for working near water.
Public Road Closure: The work required a temporary road closure, which was managed in close cooperation with Wairoa District Council (WDC). We adjusted our daily methodology to ensure the road was open for the scheduled school bus timetable (both morning and afternoon runs), maintaining public access where possible and demonstrating community consideration.
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The Pryde Solution: Precision & Compliance
To manage these challenges, we implemented a highly coordinated execution strategy:
Proactive Scheduling: We adapted the timeline by working various parts of the job concurrently to overcome delays caused by the water table and weather, ensuring that overall productivity goals were met.
Increased Environmental Consideration: Because this job took place in and near a stream, there were increased environmental requirements to ensure fish passage was not obstructed and that erosion and silt did not enter the waterways.
The Outcome
Despite significant environmental and logistical hurdles, Pryde Contracting successfully delivered the Mangatawa Stream protection and infrastructure project on time and within budget. The new rip rap protection and culvert structures provide the necessary resilience for the stream banks and roading assets.
Principal Contractor: QRS
Stakeholders: Wairoa District Council (WDC), HBRC