For the past year, MOTAT’s Aviation Hall has been defying the challenges posed by an old landfill site as it constructs its new car park and redevelops its Motions Road location in Western Springs. The development also includes a cycleway and pedestrian path that connects Meola Road to Motions Road and the paths through the Te Wai Ōrea, Western Springs Precinct.
The car park is a much-needed development for MOTAT and the Western Springs Precinct community. Visitors to the area have often voiced their frustration at the lack of parking in the area, with visitor research indicating that 1 in 4 visitors to the Auckland Zoo and MOTAT drive away after not finding a car park.
The carpark and the MOTAT Aviation Hall are located on capped landfill which makes it unsuitable for most forms of commercial and residential development. MOTAT’s car park will not only support MOTAT, the Westpoint Performing Arts Centre, Auckland Zoo, TAPAC, and local sports centres, but it will also future-proof the precinct while reducing traffic congestion and making it safer for pedestrians and cyclists to move around the area.
As we approach the end of the construction, we reflect on the challenges that were encountered and the innovative solutions that were implemented to deal with them.
Between 1930 to 1976, local residents used the land for the dumping of household waste and chemicals before the landfill was capped and subsequently leased to MOTAT. Due to decades of dumping, the land MOTAT intended for the car park contained several contaminants of concern (COCs) including heavy metals, asbestos, and polycyclic aromatic hydrocarbons often found in oil and gasoline.
Before the project started, MOTAT engaged with and got feedback from its neighbours including the Auckland Zoo, TAPAC, Ngā Puna O Waiōrea Western Springs College, Pasadena Intermediate, Seddon Fields Football Club, Westpoint Performing Arts Centre, and local Iwi.
One of the initial challenges faced by the team was data mapping the depth of the refuse in the covered landfill. While there was pre-existing desktop geotechnical information, this was limited, and the team needed to undertake an updated search to ascertain the depth of the landfill and to identify the pockets of COCs that posed a construction and health and safety hazard.
Unfortunately, the team encountered refuse and other contaminated soil at a shallower depth than shown on the original data map. This meant that the Team had to re-think the approach for the construction of the car park to minimise the risks. Through a flexible design approach, the Team devised a plan that could be adapted to the newly identified refuse-pocket locations and any other pockets that were encountered as construction progressed. This innovative approach meant problems were managed more easily as it was planned to expect these refuse pockets.
Once this pre-construction work was completed our contractors, Auckland Civil, were able to proceed with construction.
The team decided on a surface and pavement design that could accommodate the movement and challenges of an old landfill and could be easily monitored and maintained.
Another challenge of the old landfill site was the release of methane, CO2, and other gases as the rubbish breaks down over time. While these gases are harmless in small quantities they can build up and become trapped under large, paved areas like a car park.
In order to remove this potential risk, subsoil drains were laid under the car park that were in turn connected to gas catch pits with domes and grated lids that vented the gases safely away via gas extraction wells and vents.
MOTAT engaged with local Iwi in the early design stages to ensure that Kaitiakitanga was acknowledged and interwoven into the design and construction process to protect the natural environment and in particular the health of the nearby Te Tokoroa, Meola Reef. An innovative stormwater runoff plan was developed to ensure that any potentially contaminated storm water coming from the car park was properly dealt with.
A top-of-the-line pump station was installed to enable the stormwater pipes to be laid close to the surface and thereby avoid the risk of the stormwater being contaminated by the landfill refuse. Without this pump, the stormwater lines would have been 1 - 1.5 metres deeper, which would have increased the risk of contamination.
The stormwater runoff is also treated by an underground filter to remove suspended solids, hydrocarbons, and metals to ensure that the water that eventually flows into the Waitematā Harbour via the tidal portion of Waiōrea, Motions Creek is clean and good enough to drink.
One of the other challenges that was encountered was COVID-19, which extended the construction time and costs but these challenges like the others were handled professionally and with good humour by MOTAT and the construction teams.
It is also worth noting that the car park and walk/cycleway incorporate lighting and cameras to increase the safety and well-being of those using the facility.
MOTAT is proud of the team that has managed this project and we can’t wait to reopen the Aviation Hall and car park to the public on 20 August. A big thanks to those who have contributed in different ways including Auckland Civil, Auckland Council, Tātaki Auckland Unlimited, Waitematā Local Board and, Auckland Transport.
If you have any questions about the car park, where it is located, and how to use it, see our website for more details.
Story by Makayla Wallace-Tidd, Communications Coordinator, MOTAT
Wallace-Tidd, Makayla, 2022. MOTAT’s new car park is on top of a landfill and it keeps defying challenges. MOTAT Museum of Transport and Technology. Published: 11 August 2022. URL: https://www.motat.nz/collections-and-stories/stories/motats-new-car-park