Where Does The River Begin?

cu trees taggs island

Doing some research in the London Metropolitan Archives, I come across a map of all the trees on Taggs Island from 1982. We’re intrigued to find a moment to visit the island – just up river from the library and former home to Fred Karno’s Karsino – but before we do it seems right to try following the river from the centre of London out to Hampton.

Westminster to Hampton Court (twenty-two miles) takes three hours, so I decide to start by taking the small river boat from Westminster to Kew, (which is over half way of the distance) and takes about 90 minutes. Catching the first boat of the day, there are only about 15 other people on the boat and very quickly the gentle speed of the boat and the soft tones of the grey sky and water create a feeling of reverie. The boat’s captain offers a voluntary commentary, which references notable buildings along the edge of the Thames as well as facts about the bridges and Thames wildlife.  It immediately strikes me how much of the commentary is about wealth and money whether it’s about the specially built hotel for a Sheikh or ‘Luxury Riverside Apartments’ which have sprung up at an increasing number of places  along this stretch of river and dug down as they are into the flood plain are a factor in the recent increase in the height of the Thames Tide, so the captain suggests.

After we pass by Chelsea the river starts to widen and it begins to feel like the river belongs to its birds. We see cormorants and moorhens, as well as mallard ducks and even a heron.

birds on a boat

I find out that there are two tides a day on the Thames and that it takes approximately five hours for the tide to come in and a little over seven hours for it to go out. Each high tide occurs slightly more than twelve hours later than the last – pulled by the gravitational force of the moon – the tide advances.

About every two weeks – close to the new moon and full moon, there are ‘spring tides’ when there is a rise and fall between low tide and high tide of up to 8m Seven to eight days after spring tides there are ‘neap tides’. During the neap tides the water’s movement is less extreme and difference between low water and high water is around 5m.

The riverboat website emphasizes that tidal predictions are always subject to other environmental factors – such as Unfortunately, tidal predictions cannot “wind in the estuary and land water from the hills”.

Our boat’s captain predicts that the Thursday following our boat trip the Harvest super-moon may well cause the tide to swell so much that the boat will have to delay its start in order to pass underneath some of the river’s bridges.

Whilst we’re on the river it seems hard to imagine the pattern of ebb and flow of the tide – at first thought it feels like the river is quite still and that it’s the birds and the clouds that are creating a sense of movement. I enjoy looking more closely at the water and imagining the undercurrents and turning points.

We pass two small islands on the way to Kingston – Chiswick Eyot and Oliver’s Island. (Westminster itself used to be on an island called Thorny Island and there are over 80 islands in total on the Thames.)

thames island


olivers island3

Later, in a conversation with Sheila I realise that I don’t know where the river Thames begins. She tells me that it’s somewhere in a field in Gloucestershire and sure enough when I look it up, I find that it lies near the village of Kemble. The  start of the Thames – or the Thameshead – is marked by a stone and a signpost showing the start of the Thames path which is 184 miles. The river itself is 215 miles long.