Opua Boatyard Jetty, Floating Pontoon Construction and Dredging

Johnson Bros Ltd were the main contractor (self-performing 80% of the contract) and completed the design and build of the project. The dredge specific work on this contract involved JBL completing; internal pre-dredge and post-dredge surveys; dredging via hydraulic excavator, which was equipped with machine control equipment; the disposal at JBL own approved and consented disposal site; self-monitoring as required under the resource consent.

The project involved construction of; 80lm Timber Jetty - finished in purple heart timber, installation of a floating concrete pontoon (12m x 4m) with fender piles, and 7000m³ of captial dredging works.
The resource consent for the project was granted via environmental court ruling, it included very stringent and specific pre-works and monitoring during dredging. As with all projects, JBL followed resource consent requirements, including relocation of pipi shellfish bed from within the foreshore portion of the dredging footprint. Relocation of the pipi involved development of a suitable methodology, with ecological approval, which allowed the construction of specific equipment to complete the shellfish relocation.

The project was completed within the contractual timeframes and budgeted amounts. A significant number of forging objects were encountered, as the site was the footprint of a historic wharf and slipway. JBL developed a screening process to be implemented to sperate debris matter from dredge spoil to allow the material to be disposed of within the stringent resource consent conditions.