2007-2008 Labour Government Proposals
Valued @ $2.89bn with possible construction period between 2009-2015
The Waterview Connection is the last part of the South Western Motorway extensions, and will be the last section completed under the Western Ring Route project. It will also be the most expensive section at $2.89 billion.
This option of all options investigated by Transit will offer the least disruption during and after construction and is the shortest and fastest route. It will take pressure off residential streets making them safer and it will also provide an easier tri-city connection from Waitakere to Manukau through Auckland City.
There will be new interchanges at Maioro Street and Waterview (interchange with Great North Road and North Western Motorway). Ventilation shafts at each end of the tunnel and the project will provide space for rapid transit projects and the Southdown rail line.
Waterview Extension Map. Image from Transit.
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The Tunnel
Originally the plan was to create cut and cover tunnels over the length of the extension, this was far cheaper, but the ground is heavily disturbed because the tunnel is dug - then covered over.
The chosen method is twin bored tunnels, one north-westbound and one south-westbound. Both are between 20-40m below the surface and 13m apart.
Inside both tunnels are two lanes, a road reserve (total road width) of 9.7m and the tunnel (road interior) at 4.9m high. Each tunnel (outer) is 13m by 13m.
The tunnel is ventilated by two stacks, one at Waterview and one at Maioro Street. They would be between 15-20m high and dirty air from inside would meet air quality standards when expelled.
Image from Transit
The tunnel will be bored with a Tunnel Boring Machine (TBM) which excavate tunnels with a circular cross section through a variety of rock. They can be used to bore through hard rock or sand and almost anything in between. Tunnel diameters can range from a metre (done with micro-TBM's) to 15 metres. The two biggest were built in 2005 to dig two tunnels for the same urban project in Madrid, Spain. Tunnels of less than a metre or so in diameter are more typically done by horizontal directional drilling rather than by TBM's.
Tunnel boring machines are used as an alternative to drilling and blasting methods. A TBM has the advantages of not disturbing surrounding soil and producing a smooth tunnel wall. This significantly reduces the cost of lining the tunnel, and makes them suitable to use in built-up areas. The key disadvantage is cost. TBM's are expensive to construct, difficult to transport and require significant infrastructure.
Tunnel boring can take a few days to cover a few metres, if you live in a property above the TBM it may be there for a couple of days, it may cause some light vibration. As Transit puts it "like a fridge rattling" depending on how old the fridge is, it could be a rattle or a shake.
Due to the length some radio stations will invest in providing signal when you are in the tunnel, so they offer uninterrupted service while traveling over the 4km section.
This would be the fourth project in Auckland to have tunneling investigated or involved; the Northern Motorway Extension twin tunnels the Auckland Harbour Crossing twin sunken tunnels and the Victoria Park cut and cover Tunnel.
Depth perspective of the tunnel. Image from Transit
Maioro Street Interchange, South Western tunnel portal. Image from Transit
For more information on Tunnel Boring and similar project worldwide have a look on Wikipedia here.
Funding
This is an expensive project, coming in at $2.89b. The government will not commit to a project that expensive if it doesn't have to, so has seeked alternative means of funding. One way is through Public-Private Partnership (PPP), this system is a popular way of funding expensive projects, ones that are usually highly desired but provide alternatives when an original route is already in place e.g. the Penlink project in Whangaparaoa, or the defunct Eastern Corridor.
This system of PPP is popular internationally and in Australia where it has seen numerous transport projects completed, namely tunnels and even a hospital.
Definition: Public-private partnership (PPP) describes a government service or private business venture which is funded and operated through a partnership of government and one or more private sector companies.
This does not mean that the road would be privatised, but is leased to a company, where it collects money made from it possibly in the form of tolls.
Annette King has said that if PPP is not sought, the project will go ahead with full funding from the government. Currently how the PPP would be ran is under speculation.
For more information on PPP's take a look at the Wikipedia page.
Controversy
People are asking the question is this project really worth $2.89b. Even with the PPP this may not all be taxpayers money. But the question of spending money and time on a 4km section of motorway this expensive vs. fast tracking electrification of Auckland's Rail and public transport investment etc. keeps coming up.
If this project is constructed will this slow down other more important infrastructure projects like the Auckland Harbour Crossing, Victoria Viaduct Tunnel, Rail Electrification and the Inner City Rail Loop?
Considering in the next few years that the price of oil will rise dramatically and people using vehicles will make shorter, smarter trips, and change their place of work. Would a tunnel that was just completed that had 4 lanes for traffic and cost $2b be worth what was paid for?
From a user came this comment:
"The problem is that people want the motorway, but they don't want the motorway. In other words (to pardon the double Dutch), they want the provision of a fast roadway without the impact of the road - thus they want a tunnel. People want the motorway or they don't, they simply can't have their cake and eat it in this case. I say give the whole thing to a private company, let them charge people who want to drive to death and at least then they can't complain about lack of provision. It's the residents who want the tunnel, let them pay for the tunnel through exorbitant tolls.
Its funny how quickly funding seems to come to the Governments lips when it concerns a roadway compared to the Inner City Rail Loop and even electrification (which has slipped to the back burner). This will be (at present) NZ's largest ever spend on infrastructure. Is this link really worth it?"
One thing to remember is that this is the last piece of the Western Ring Route, all other projects are under construction or complete. So it would be a waste of already invested money not to complete the network, but at what cost?
Above: Results from polling on this website about the project.
