Work to extend Marlborough’s Pukaka Quarry is well underway, freeing up more armour rock for the region.
Senior Rivers Engineer Frank Westergard was pleased to see progress on the extension over the winter months, bringing a plan some years in the making to life.
“Favourable weather enabled a dry-weather dumper haul road to be completed to all the upper quarry benches. Work is now focused on preparing the back boundary of the quarry for permanent fencing. The stormwater bunds and settlement ponds on the quarry floor are also in the process of being enlarged to cater for the increased stormwater catchment area,” he said.
“The quarry operator has begun benching the eastern face of west knob to create a second work face to complement the top bench. Extraction of hard rock by explosives took place in mid-September, the first such operation in three years.”
It’s expected west knob will provide lower-grade armour rock, while the top benches continue to produce large rubble material - both for use in flood damage repairs next year. Large high-grade armour rock is well-buried in the quarry but should become extractable within the next 12 months.
The west knob should also produce crushable material to replenish aggregate stockpiles, which will play a small part in addressing the district-wide demands for aggregate.
Pukaka Quarry, near Rārangi, was a key supplier of armour rock for construction of the Wairau River Flood Protection Scheme in the 1960s. Council acquired the quarry in the 1990s to ensure this strategically important rock supply remained available to Council, but by the early 2010s, the ability to extract rock was becoming limited by property boundaries.
“A project commenced at that time to expand Pukaka Quarry and maintain Marlborough’s supply of armour rock, and the process of acquiring land from the neighbouring landowner and obtaining resource consents for expansion concluded in 2022,” Frank says.
“In late 2022, the development of the quarry extension began in earnest, with commencement of earthworks to strip the overburden and establish an internal haul road.”
The quarry extension will enhance the supply of rock products to the district for several decades to come. In the short term, it will provide material for repairs to the Wairau Diversion and Lower Wairau floodways after the 2021 and 2022 storms.