Steep, rocky, and accessible only by water, many parts of the Northern Beaches are as secluded as they are beautiful. But with the Mona Vale area earmarked for a new NBN connection, a thoughtful and well-planned HDD approach was required to ensure Northern Beaches locals will be even better connected.
Too isolated for large populations, and with ground conditions too hard for farming, the Northern Beaches’ natural beauty has endured. With many locals living amongst the secluded beaches and national park areas, with modern times have come modern demands, including rollout of the NBN to the area via the Mona Vale Western Bay NBN Outfalls. Thus, the challenge was presented: how best to install this vital infrastructure in such an inaccessible, environmentally sensitive location, with rock conditions?
The project was bound from the start by rigorous environmental conditions. With much of the location covered by Ku-ring-gai Chase National Park, a trenchless solution was non-negotiable in order to minimise environmental impact. Central Coast-based HDD specialists Superior HDD were engaged by Downer to complete the 4 x HDD ocean outfall connections of the HDPE pipes.
James explained that his priority was first to fully understand the project’s risks in detail. “We know the ground conditions in this area very well, and while the consistent Hawkesbury sandstone provides hard but predictable drilling conditions, being such a sensitive area, hydrofracture was not an option,” he said. “So we had our HDD design specialists complete a detailed profile and alignment and hydrofracture assessment, coming up with an ultraconservative, deep profile to minimise frac-out from that perspective,” he said.
monitor, and analyse our returns for the entirety of the bores.”
showcase the accuracy and environmental benefits of HDD with this project, proving that with good preparation and risk mitigation, it’s a safe, responsible method in even the most pristine environments.”
The final of the four connections was completed in late September, on budget and within required timelines.
“We were proud to showcase the accuracy and environmental benefits of HDD with this project, proving that with good preparation and risk mitigation, it’s a safe, responsible method in even the most pristine environments.”