Tuesday, April 13, 2010

Why the Thames Tunnel is Controversial

The Thames Tunnel described in yesterday's post is designed to stop 32 million cubic metres of untreated sewage from entering the Thames each year, where it plays havoc with the wildlife and water sports enthusiasts alike. The 50 - 60 discharge "events" per year are above the maximum levels in the EU Urban Waste Water Treatment Directive 1991.

Supporters include Thames 21, Peter Ackroyd, the RYA and Olympic kayaking champion Tim Brabants (see more here).

How can such a project be controversial?

Well it is, and for two reasons. Firstly cost: as you'd imagine a 32 km long tunnel 75 m underneath the Thames does not come cheap - in fact estimates are around £2.2 billion. And this is going to come from just one source - residents of London through higher water bills.

The second is that access is going to be required to water front or adjacent locations from which bore shafts can be constructed through which to drop machinery and extract soil. And quite big machines and quite a lot of soil.

To give you an idea of the scale, the figure above from Thames Water shows a cross section in which fits three London double decker buses.

In fact "Thames Water anticipate that for the Main Tunnel Drive Shafts the typical construction duration is 6 to 7 years with indicative peak HGV traffic movements of 120 vehicles per day." (*)

You can see that this might not be popular.

So the Borough of Hammersmith and Fulham, which is currently the proposed start point of the tunnel, are raising objections - "Super sewer crater opposed". But they won't be alone - the report suggests that secondary sites will have to be located all along the river.

Watch this space, as they say.

(*) See this Wandsworth Council Planning Report, 1st March 2010.


tillerman said...

Shit! You gotta move it.

Pat said...

For those of us not in the news loop, how is the Thames Tunnel going to reduce pollution in the river; how is it supposed to work?

tillerman said...

Pat, the tunnel will capture flows from the 34 most polluting sewer overflows that discharge untreated sewage to the River Thames and transfer that sewage to a sewage treatment plant.

doryman said...

And Londoners shouldn't pay for cleaning up their #%&@ ? The big question is why does the waterway always pay the price (which is not in pounds).

Carol Anne said...

Yikes! It is undoubtedly an extremely important project, but a price tag in the billions (with a B), and in pounds, which are bigger than dollars, leaves me stunned.

Still, it is also urgently needed. The Thames is a lot less polluted than it used to be, and that has been a Very Good Thing. We want to keep it that way.

Eau Gazeuse said...

I sailed last year after a period of heavy rain and large discharges in the Thames, and I can guarantee that it's NOT pleasant.
I understand the cost and the heavy work won't be easy, but what are the alternatives? Building a sewage treatment plant in Chelsea ?

JP said...

In dollars it would be about $ 3.3 billion, and even averaging over 8 years over all Londoners that's still a hefty bill.

As a sailor / kayaker who also cares about the environment I certainly think its a good idea, even given the cost and disruption.

However a niggling thought is that I've seen documentaries about slums in 3rd world where sewage runs through the street of the mega cities and wonder if we're being a bit over zealous.

I suppose you can only tackle those problems one at a time, so lets go ahead and solve this one.