Bristol is a city built around a river, the ‘place of the bridge’ which has been an important crossing point and port for a millennia or more.
The key to the city’s very existence is the River Avon, which flows in from Bath in the south east and out north west up the Avon Gorge.
But in the 21st century – and indeed for 210 years – the city has two distinct and very different bodies of water, each with its own character.
There’s the Floating Harbour, with its historic docks, railway, paddle-boarders, boats, little marinas and balcony-lined upmarket flats.
Then there’s the River Avon, with its deep embankments, rising and falling, fast-flowing tides and ever-changing patterns of thick, treacherous mud.
But there’s a quirk of Bristol’s bodies of water that people who move to Bristol might not spot, and those who were born and raised here might not have realised.
It’s a bit complicated, and is to do with what each body of water actually is – a river? The sea? A canal? An artificial waterway?
Let’s start with the Floating Harbour
It starts at Netham Locks and goes in a straight line all the way to a spot around the back of Temple Meads Station, in a spot called Totterdown Basin close to Motion nightclub.
Then it winds its way from east to west in a curving path first north to Castle Park, then bending south to Welsh Back, before turning west and following a wiggly line to the Cumberland Basin.
Another stretch of the Floating Harbour starts at the Cascade Steps and goes south, joining the main Floating Harbour at the Arnolfini.
We know this – it’s Bristol’s second most famous geographical feature. It’s not quite the line of the Thames around Canary Wharf that everyone knows from EastEnders, but most Bristol people would recognise the shape if you were to draw it out.
So what is the Floating Harbour?
It’s a river?
No, it was a river. It was the original course of the River Avon, flowing in from Bath and Keynsham, and looping around to the spot at Bristol Bridge where the first bridge was built.
In 1809 it stopped being simply Bristol Harbour and became the Floating Harbour when the western end was stopped up by the great lock gates at the Cumberland Basin and at Netham Locks, trapping the high tide in and keeping a constant, reliable level of water in the docks of Bristol.
So it’s an artificial waterway?
That was a game changer – not just for the merchants and ship’s captains of the city. It meant that the floating harbour was effectively a naturally-created, artificially-maintained waterway, except for the straight bit out to the east, called the Feeder.
That is a wholly-man-made, artificially dug canal that forms the eastern half of what is a naturally-created, artificial waterway.
But it IS still a river?
Yes. So while you’re looking at the placid waters of the Floating Harbour on top, underneath, it’s actually also a flowing river.
The River Frome comes into Bristol on an ancient path that follows the valley used most recently by the M32. You can paddle in it at Snuff Mills and Oldbury Court, and look into its murky depths by the side of Ikea.
Just before Cabot Circus, it disappears into a long tunnel right under the city centre.
It used to be completely open, and follow a line which was first culverted off to form a moat for the castle at Castle Park and then on through what is now Broadmead, around the old city and into what is now The Centre.
The river used to flow in a different direction and merge with the River Avon somewhere along Welsh Back, but in the 14th century, a new channel was dug to create St Augustine’s Reach, to create more space for ships to moor up. That gave us the waterway shape we’re used to now.
But it was even a bit more complicated than that – connections between the River Frome and the tidal River Avon were dug across what is now Castle Park and Old Market, which sometimes flowed one way and sometimes the other, depending on the time of day.
These sections of the main course of the River Frome to the Floating Harbour next to Castle Park are still there, as tunnels under the park and the city centre.
But that was more than 200 years ago – today, the River Frome flows out into the Floating Harbour where the tunnel emerges next to the Cascade Steps, and continues into that artificial lake.
It does an important job under the surface, for the imperceptible flow out from St Augustine’s Reach to the Cumberland Basin, released by Brunel’s complicated lock and pump system, does the job of stopping the Floating Harbour getting too silted up.
And then there’s the New Cut
So the River Avon from Netham Lock to the Cumberland Basin is also a mixed bag of things.
From Netham Lock to a point just south of Temple Meads Station – roughly where the ‘Bridge to Nowhere’ crosses to what is now known as ‘Temple Island’ (even though it’s not an island) – it is a river that naturally follows the natural and historic path of the River Avon. It is what it says it is and looks like it is.
But from that point at Temple Island onwards, it flows into the New Cut – an artificial channel which took five years to dig, between roughly Bath Road Bridge and the Cumberland Basin.
When it opened in 1809, the river switched from flowing north at Temple Island around the city centre, and instead followed a fairly straight, artificial path along and under the place that is now Bedminster Bridge, between what soon became Southville and Spike Island, and Ashton and the Cumberland Basin.
Its walls were built high, to cope with the huge high tides that had previously brought such a daily issue for the city centre.
The mud soon built up, and the walls are beginning to show a spot of wear and tear and, in some parts, total collapse.
So the River Avon through Bristol is half the time a natural river, and for half its course it flows down an artificial channel.
And then there’s the fact that twice a day, the sea rushes in and fills that artificial channel not with river water from Bath and the Wiltshire Cotswolds, but with muddy, silty brown sea water from the Bristol Channel.
So let’s clarify this
The Floating Harbour from Netham Lock is a man-made canal for half its length and then it’s a naturally-created, artificially stopped up waterway for the other half of its length, while simultaneously for a third of its length, being a natural river that has flowed out of an artificial tunnel.
And the River Avon is a naturally-created, natural river for the first half of its length, and then a naturally-flowing river in an artificially, man-made canal channel for the other half of its length, but twice a day it becomes neither of those things and is effectively the sea, when the tide comes in and fulfills its definition requirement of the River Avon at this point still being a tidal estuary.
The Floating Harbour is a former natural river, now an artificial waterway, a wholly-artificial canal, and still a natural river, all at the same time.
The River Avon is both a natural river and a river flowing down an artificial waterway and sometimes is the sea. And that’s as clear as the river at high tide.