Auckland Council is leading extensive engineering works at the Rawene Road car park in Birkenhead to ensure the safety of the surrounding area where two slips have recently taken place.
Work will continue on a long-term solution. Here are the key things you need to know.
Last updated: 1 March 2018
What happened at the Rawene Reserve car park?
Two land slips occurred at a car park at Rawene Reserve, Birkenhead on 8/9 October and 28 November. The slips carried away car park tarmac and debris, as well as lamp posts and machinery which were being used in the repair of the October slip.
The car park had already been closed off on 20 September by Auckland Transport for safety reasons as cracks that had appeared in the tarmac had got worse.
What caused the slip?
It is too early to be certain what the causes of the slips are. Initial technical investigations suggest that it is unlikely that stormwater pipes played any significant role in either slip.
Auckland Council engineers and technical specialists are continuing with investigations, but this work is complicated by the instability of the site and concerns for staff safety.
Will the slip get worse?
It’s likely that small amounts of material will continue to fall from the steep front face of the slip. Our investigations show that the slip is not likely to regress too much further. We have installed inclinometers, piezometers and survey points which are being monitored to give us early warning of any future movement.
What is the risk to the shops on Mokoia Road?
We would not be doing this work if there was no risk. However, since the second slip on 28 November the regression of the slip has been extremely slow. Despite extensive monitoring and surveying we have not seen any indications of movement that would threaten any of the buildings.
With the sheet piles now in place the risk has reduced to more normal levels, meaning that there should not be a need to worry about the potential destabilising effect of heavy rain.
I own a property that has lost some land, what will be done about this?
No decisions have been made about final designs. We will be consulting with you soon about the best options, and encourage you to discuss the matter with your insurer. We will be happy to share the factual information collected during our investigation to assist your insurer.
I own a property that has fill slip material moved onto it, what will be done about this?
No decisions have been made about final designs. We will be consulting with you soon about the best options. These may include moving all the material, or stabilising the material where it is then reshaping the material to a natural form and re-planting it.
Please bear in mind that this material may contain some contamination. Small sheets of asbestos have been found on part of the site, and the original slip damaged a sewer that then leaked for a short period before it could be repaired. The risk to human health from both of these is low as long as people stay off the slipped material.
Will any of the works require resource consent?
Yes, the next steps will require resource consents and will have to go through the normal consenting process, including consultation. It is expected that some of the consenting process can happen in parallel with design and consultation, and that it shouldn’t slow progress on site significantly unless there are a lot of objections.
Why are there cracks in the ground behind the sheet piles?
When we install the sheet piles we have to excavate a trench about 1.5 metres deep first, in order to clear out obstructions and check that there are no unmarked buried services such as gas pipelines. Relaxation of the ground near these trenches can cause localised cracking, but it poses no risk to the buildings and will be fixed once the sheet piles are installed.
What are the generators being used for?
The generators are being used when heavy rain is forecast. These remove the over land flow further down the gully away from the landslide helping to reduce erosion at the top of the landslide.
Who can I call if during heavy rain I see a potential threat/flood hazard?
If life is at risk please call 111 to request emergency services, followed by a call to Auckland Council Building Control. If you are concerned about property please contact Building Control in the first instance. The help centre phone number is 09 301 0101.
Parking enforcement was supposed to have begun last week – why are people still parking illegally in the Rawene Road carpark?
Auckland Transport have noted that in regards to enforcement they did take a soft compliance approach for the first week and focussed on getting visibility with the local businesses and community rather than issuing infringements. Auckland Transport confirmed that they patrolled the wider Highbury area three times last week and the carpark twice. They are now going to increase their focus on non-compliant vehicles and this will include attendance to the off-street carpark on Rawene Road.
Q&As from public meeting held on Tuesday 13 February 2018
The following are some questions and answers from the public meeting on Tuesday, 13 February. If you have any other questions that you would like to ask, please email rawene@aucklandcouncil.govt.nz
What is the likelihood of slips/subsidence in other areas of Highbury/Birkenhead?
There is no evidence of more large scale landslides. We are aware of other places in Birkenhead, often in car parks, with cracks and rough terrain but in all instances, the evidence is it’s localised meaning it isn’t spreading in depth or width.
How can we get more car parking ?
We will open as much of the car park as we can as soon as we can. The Rawene Road car park will be needed again in the future for access to the site as we work on the site, so parking can only be available temporarily while site works are stopped. The car park will be re-marked to accommodate as many spaces as possible. We will do our best to keep as many spaces open as we can during construction works, and to work as fast as we can to minimize the impact.
What is being done to address enforcement in the car park and misuse of the disabled car parks?
There have been some incidents of misuse of the disabled car parks. We apologise for this and can confirm that we have spoken to those at fault.. If you see any further misuse of the disable parking spaces please let us know.
Auckland Transport has advised that in consultation with the Birkenhead Town Centre Association, enforcement of parking times will begin again on Monday 19th February.
Has anyone thought of a car park building?
A parking building may be considered, but – as with any other development – would require a private developer to be involved in funding it, and it may need other uses (such as shops, apartments or hotels) to make the development financially viable. It would also need to take into account the pressure that additional parking would put on the local roads. To avoid gridlock there may have to be a cap on the number of spaces.
Where will the storm water drain in the gully go?
The drain will go from the crest of the slip to the inlet culvert at the top end of the Chelsea Estate, then into the ponds.
Can you give details of how high a hotel might be on site?
Whilst Council has a proposal of interest from a developer relating to the site, detailed plans have not yet been presented to council. Any detailed proposal would require resource consent, which we expect would be publically notified, so there would be an opportunity to give specific feedback on heights at this later stage.
We are currently asking for broader feedback on what the community might like to see on the site. This may or may not be a building, and the potential height for any such development is certainly undecided at this point.
Can you tell us how high a building could be under the Unitary Plan for this site?
Currently the bulk of the site is still zoned for reserve purposes, although some of the landslide has impacted on private land (generally zoned for residential purposes). As it stands, the previous car park area was zoned ‘Business – Town Centre Zone’ with a height limit of 21 metres or 27 metres, varying across the site.
If there is a third-party enterprise on public land, would the land remain in public ownership?
The landslide site is currently reserve land. There are a lot of steps required to revoke reserve status, including consultation. In a situation like this, Council might continue to own the land and have an agreement to lease the land with the third-party, or in some circumstances might consider sale of the land.
How can I keep up with what's happening?
Regular updates are available about the Rawene Project here on OurAuckland. To subscribe to receive these updates or to ask questions about the Rawene project email rawene@aucklandcouncil.govt.nz
Information is also available on the Auckland Council website.
