Between 1750 and 1810 London doubled in size.
From 750,000 to one and a half million people.
It was the largest, most overcrowded city in the world.
It hadn’t grown by plan, it just happened.
Consequently there was no infrastructure for that many people.
There were no sewers in those days: every house had a cesspit.
That meant two hundred thousand cesspits all over London.
And most of them were overflowing.
Into the alleys, into the streets, then back into the houses.
Down the walls and into the basements where the poorest slept.
A quick fix was to divert all that raw sewage into the drains.
The drains that carried the rainwater into the Thames.
The Thames, where the water companies pumped the drinking water from.
And two massive cholera outbreaks killed tens of thousands of people.
But it wasn’t until “The Big Stink” of 1858 that the authorities took much notice.
The Thames flows right past Parliament, and the stench of raw sewage was so overpowering, the enormous hanging curtains in the House of Commons had to be soaked in Chloride of Lime.
But even that couldn’t cover “The Big Stink”.
So Joseph Bazalgette, the Chief Engineer of the Metropolitan Board of Works, designed and built the first system of enclosed sewers.
A massive, entirely brick-built project.
Over a thousand miles of street sewers which would empty into eighty miles of main sewers, all of it underground.
And take all that human waste away from London.
But the part that impressed me most was the way Bazalgette designed the sewers.
He took into account everyone living in London.
He made the diameter of the sewers more than enough to handle everyone’s waste.
Then he did something unthinkable to most people.
He doubled it.
Let’s repeat that.
He calculated the most that could possibly be needed.
Then he doubled it.
Bazalgette said “We’re only going to be doing this once. We’d better allow for the unforeseen.”
If only everyone had that much nous.
To allow for the unforeseen.
What no one could possibly have foreseen, when Bazalgette built those sewers, was a hundred years into the future.
In the 1960s, councils all over London would be building massive high-rise blocks of flats.
Huge multi-story dwellings everywhere, emptying their waste into those hundred year-old Victorian sewers.
If Bazalgette had stuck to the original specification, the sewers would have overflowed back up into the streets.
But they didn’t.
Because Bazalgette had doubled the original specification.
He made the sewers well over-spec.
He didn’t try to get away with the bare minimum.
The way most people do.
Spend absolutely the least possible amount we can get away with.
Do the job on as tight a budget as possible.
Skimp, and call it efficiency.
We need to learn a lesson from Bazalgette about doing a job properly.
Stop thinking under-spec and start thinking over-spec.