Four years of construction and The Oaks on Neville retirement village is finally on the home straight, after crossing a number of hurdles along the way.
The biggest structures ever built in Warkworth’s CBD contain 62 units, resident facilities and a number of ground floor retail shops.
Project manager Dave Stott, who has had international experience on large construction projects, says the early stages of the Oaks build were as testing as anything he had come across in his career.
After joining the project team in 2014, he faced his first difficulty when plans were changed to accommodate new code requirements and improve the layout of the buildings.
“Following the Christchurch earthquake, a number of new rules came into play so we were forced to redesign the superstructure,” Dave says.
“This meant we decided to keep the contractor on who was doing the piling for further groundworks and, as a result, things went slower than anticipated.”
The change in layout meant that a stormwater drainage pipe had to be redirected and had to zigzag around structural work, which had already been done.
Once design plans were finalised, earthworks and piling started, but ran in to difficulty because of the high water table.
“Every time we tried to dig a trench of any sort it would collapse, so we had to put in a drainage system to distribute the water so the clay was dry enough to move.”
Groundwater continued to be the main challenge for the rest of the project, with the underground carpark going down well below the water level.
“Four metres of water pressure is huge so we had to build the superstructure before the carpark, otherwise it would have popped out of the ground.
“We also devised a system to keep the water down to its median summer season level, which was probably the most complex part of the whole project, but has worked well.”
Other related tasks included constant monitoring of the water levels below surrounding businesses and the use of silt traps to avoid environmental damage.
Dave says once water levels were under control, the build was relatively straightforward.
“There were more than 100 variations to the plan, but that is very little compared to the 15,000 or so that were done during the construction of the Mount Eden prison, which I was also involved in.
“I would have liked to have seen the project finished a few months earlier, but I think we moved as quickly as we could under the circumstances.”