Mairaki Rd Drainage Improvements

Chinnery Construction delivered the replacement of two existing 1200 mm aluminium culverts with a new 3 m × 2 m precast box culvert, significantly improving the capacity and performance of the existing crossing. The works included the installation of the associated structural components, along with all required excavation, backfilling, and compaction to properly integrate the new structure into the surrounding ground conditions.

Inlet and outlet channels were reshaped to enhance stormwater flow and improve hydraulic efficiency through the structure. Existing timber retaining walls were carefully retained and protected throughout the construction process to maintain site stability and avoid unnecessary disturbance.

On completion, all disturbed areas were reinstated, with finishing works carried out to deliver a durable, clean, and well-resolved outcome consistent with the surrounding environment.