Interview: Andrew Mitchell, chief executive, Thames tideway tunnel

“If all we did was build a sewer and get crap out of the Thames, it would demonstrate a distinct lack of imagination.”

Tunnelling under the Thames was never going to be easy, but Andrew Mitchell, chief executive of the Thames Tideway Tunnel, has experience of managing tricky projects on a grand scale. The former programme director at Crossrail joined Thames last spring and, in a little under a year, has seen away a clutch of judicial challenges, winning victory in the planning halls, with the tunnel now fully consented and work set to start next year. Meeting Utility Week as he prepares for another action-packed year, Mitchell outlines his plans for a “new water company”, and the super-sewer that he believes will breathe new life into the Thames.

The planning issues around the tunnel are now all but resolved. Last week, the High Court rejected four appeals for a judicial review of the project. It won full planning permission in September last year, despite pockets of vociferous local opposition, and a concerted campaign by figures including Liberal Democrat MP Simon Hughes. While not everyone is satisfied that the tunnel is the best way to solve London’s sewerage problems, it seems clear the mega-project will go ahead as planned. Indeed, the remaining questions centre on its financing, the detail of the construction and the project’s potential once built.

Due to the significant cost of the super sewer – £4.2 billion at the last count – Thames Water is setting up and then in effect selling on the venture, creating a new utility company. The water company has done battle several times with Ofwat over the funding of the tunnel, beginning with its request to raise customer bills at the end of the AMP5 cycle, the attempted IDoK that was rejected by Ofwat in 2013. Its proposed charges relating to the Thames Tunnel in AMP6 have also caused issues in the PR14 cycle, though these appear to be approaching resolution, with Ofwat granting Thames various allowances relating to the tunnel in its final determination, which Thames seems likely to accept.

Mitchell acknowledges that the establishment of a separate company is an “unusual process”. He says: “[We’re] setting up a new water company from scratch – which technically hasn’t been done before as all the previous water companies were part of existing industry that was packaged up. [It’s] giving birth to a new water company.”

But before the Thames Tideway tunnel is cast out into the world, Thames Water is nurturing its offspring and helping it to establish a footing. The process will be far from straightforward as it goes through “uncharted territory”, something that is throwing up “some interesting tensions and dynamics”, according to Mitchell.

“My team [is] part of Thames Water at the moment, but we have to be wearing the hat of the new company and inevitably there is a need to make sure that those agreements are fair and straight. Sometimes there is a sense that this organisation needs to have some healthy debates with itself.”

Mitchell believes the gestation of the Thames Tideway Tunnel IP could set the blueprint for other major infrastructure projects – especially as the government presses ahead with its National Infrastructure Plan (NIP) in financially constrained times. The NIP is a blueprint for government spending across the next two decades, highlighting 646 crucial infrastructure spending programmes.

“The government’s NIP is just a list if we don’t get reliable, trusted, respected mechanisms for securing private investment. So I think we are blazing a trail.”

There “is a lot of money looking for a home” in the world, and the Thames Tideway Tunnel company is not just a way of digging holes across London, it is also “demonstrating a mechanism of how to bring private money to infrastructure investment”.

Mitchell is keenly aware of this pressure – on top of getting the much-needed super-sewer built. “There is a lot riding on this,” he says. “But we are aware of that.”

Adding to the pressure have been the threats of legal action – with two judicial review applications coming from the Blue-Green campaigners, who are keen to soften up the hardstandings of London, implement sustainable drainage systems (Suds) and prevent the tunnel being built in the first place.

Mitchell bats away comments on the judicial review hearings and subsequent appeals – “this is a matter for the court to deal with” – but will be drawn on the issue of blue-greening London and the Thames (the linking of urban infrastructure to urban vegetation, as opposed to the creation of projects such as the sewer).

“Somewhere along the line in the past five or six years, this has become a very polarised debate of either or. And it just shouldn’t be. It’s not an either or, it’s a both,” he says.

His basis for this view is that on their own, Suds and blue-greening will not be able to cope with the growth of London and the increasing pressures on the existing sewage infrastructure.

A combination of the two is not just a good idea, but essential. Without a “coherent blue-green solution” alongside the tunnel, you will “accelerate the point at which what we’re doing becomes inadequate again and you have to consider a third tunnel. That would be wrong.”

Mitchell’s enthusiasm for the controversial super-sewer is palpable – and his inspiration soon becomes clear. Sir Joseph Bazalgette, the engineer and brain behind the Victorian combined sewers, is one of his heroes. Bazalgette and his system of sewers “made sense” in the late 19th century, according to Mitchell. He adds: “You had rivers that were pretty much sewers anyway and that’s where rainwater and sewage met for the first time. Everything that’s happened since then has been a perpetuation of that basic principle.”

But with the antiquated Victorian sewers now overwhelmed – they were designed to deal with the waste of 4 million people and struggle to cope with the 6.2 million Londoners living in the city today – Mitchell is determined to leave a legacy of a cleaner river with a suitable sewer solution for future generations. That is more than just the tunnel itself.

“If all we did was build a sewer and get crap out of the Thames, I guess that is what it said on the tin. But if that is all we do, it will demonstrate a distinct lack of imagination.”

That imagination comes with re-engaging with the Thames. The starting point is making it cleaner – at the moment only the “hardened enthusiast” currently uses it, rather than it being a public space. And Mitchell is keen to point out that as a public space, “it is seven times the size of all the other London parks put together”. He adds: “For most people the Thames is the brown bit between north and south London”, and that this is an opportunity to change that.

And alongside the leisure potential for the Thames in a post-tunnel London, Mitchell also holds grand visions for a transport revolution. This is already happening. A key part of the planning behind the tunnel has been around the transportation of materials in and out of the 24 construction sites across London. The easiest option – and one that will circumnavigate the infamous London rush hour traffic – is to use the Thames itself.

Freight on the river will quadruple when construction gets under way in 2016, and to cope with the additional river traffic, Thames Tideway Tunnel is working with London Thamesport on a “massive training programme” so the volume of freight can be handled.

“It will enable part of industry that has not been there for a long period of time,” says Mitchell. “What can we do with that?” There will be significant spare capacity, built up with years and millions of pounds’ worth of investment – so it will be a case of using it for other construction projects, moving people around the city, and possibly even retail delivery.

“It is as much a marine job as it is a tunnelling job,” says Mitchell. “The more access from the river than the road, the better it is for everyone. Doing it like this is not normal and certainly not normal for this city. We are bringing innovative solutions to the construction process, which is fascinating. The more we get into it, the more we will find elegant solutions.”

Back to the here and now, there is much to be done before construction of the project can begin. Aside from getting the finance sorted, and separating Thames Tideway Tunnel from Thames Water, there is the not insignificant issue of designing and building the tunnel boring machines.

Six tunnelling machines need to be built – “sadly, this is no longer done in the UK” – and here Mitchell comes into his own. He was involved in the Crossrail project, with all its “intricate” drilling under the packed streets. Likewise, drilling through the deep chalk of the region has been done – and recently – with the Lee Tunnel.

“Bring the two together and you’ve got the Thames Tideway Tunnel. It is big shaft and big tunnel engineering. It is big boys’ toys and it’s great.”

Will Mitchell be on the front line when the tunnel is being dug?

“I am going to be out there with my hard hat on. I just won’t be able to resist it. I am an engineer, I promise you – but you’ve got to look at things this way: it is so much more than just a pipe.”