Keeping the conversation flowing over the source of a river

Pith helmet at the ready, David Gill is off in search of the source of Croydon's river, and is looking beyond Wandle Park

Pith helmet at the ready, David Gill is in search of the source of Croydon’s river, and is looking beyond Wandle Park

CROYDON COMMENTARY: Locating the source of the River Wandle ought to be reasonably straightforward, though DAVID GILL says that his latest project has raised a few eyebrows

The conversation usually starts something like this:

“So David, have got this right? Someone is paying you to find the source of the River Wandle?”

“Yep, that’s right.”

“OK, there are some silly people out there. Let me tell them that the Wandle starts in Waddon Ponds – simple and easy!”

“You are sort of right… but it does not end there.”

“How do you mean?”

“Take a walk in Wandle Park and you will see a small river. This is the start of Wandle today.”

“Oh, so its starts in Wandle Park. That wasn’t difficult was it?”

“Well, again you are sort of right…”

“Go on…”

Tesco Express: the acknolwedged source of the River Wandle

Tesco Express: the acknowledged source of the River Wandle

“Historical evidence tells that the Wandle used to start where the Swan and Sugar Loaf pub is now in South Croydon.”

“What? … the one that is now a Tesco Express? On the Brighton Road in South Croydon?”

“You’ve got it…but it does not end there.”

“Go on…”

“Do you remember the awful floods back?”

“The ones that affected Kenley and Purley?”


“Go on…”

“Well some people believe that this is connected to the River Wandle.”

“How can that be? Purley and Wandle Park are miles apart.”

The flooding of the Caterham Bourne is being linked by some to the River Wandle

The flooding of the Caterham Bourne is being linked by some to the River Wandle

“Well observed my friend… Purley and Kenley are well south of Croydon, as you know. They are both built on a rock called chalk.”

“That’s the white stuff isn’t it?”

“Yes… the chalk is porous. That means it allows water to flow down through it.”

“Go on…”

“When rain falls on the chalk, at places like Kenley and Purley, some of that rain disappears under the ground because the chalk is porous…it disappears in to an underground river.”

“So you are saying there is an underground river somewhere below Purley?”

“Yes sort of… occasionally because of lots of rain the water comes up to the surface of the ground to cause flooding.”

“And this underground river is there all the time and somehow flows under the ground and comes out of the ground at Wandle Park in Croydon?”

“Yes sort of…”

“Wow, that’s incredible.”

“Yes it is…”

“Wow, David you are genius!”

“Yes I know.”

“It doesn’t mean they have to pay you though.”

If you would like to find out more about David Gill’s research project, called Discovering the Source of the River Wandle, then do check out or give him a call on 07468 529 312 or drop him a line to

  • David Gill is the education officer of the Wandle Trust

  • Inside Croydon is Croydon’s only independent news source, still based in the heart of the borough. In 2016, we averaged 17,000 page views every week
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News, views and analysis about the people of Croydon, their lives and political times in the diverse and most-populated borough in London. Based in Croydon and edited by Steven Downes. To contact us, please email
This entry was posted in Croydon parks, Education, Environment, History, Kenley, Purley, Waddon, Wandle Park and tagged , , , . Bookmark the permalink.

4 Responses to Keeping the conversation flowing over the source of a river

  1. The Council drainage team could give you “chapter and verse” on the Wandle and its relationship to the Caterham and Merstham Bournes. Problem is that the team no longer exists through retirement, redundancy etc. Records/plans may exist in the Council offices.

  2. Lewis White says:

    Sounds a really interesting challenge, requiring a Sherlock Holmes tenacity to expose the underground sources–rather like Inside Croydon.

    We have the Victorians to blame for strip-developing the once beautiful downland valleys of South Croydon, Purley, Kenley and Whyteleafe with terraces of houses, many of which are built right in the valley bottom–the very place that the ground water came up the surface a few years ago. Unlike most forms of flooding, it is nigh-on impossible to deal with floods that come upwards, with irresistible force.

    I would love to wind the clock back and get rid of these houses, restoring a green and grassy valley bottom, from the Caterham valley to Wandle Park. If all the road gullies and illegal sewer connections could be diverted into the foul sewer and conveyed for treatment to Beddington Treatment works, the Wandle could be brought back as a crystalline chalk stream.

    We could then resume trout fishing by Croydon Minster, and gather watercress by the Swan and Sugar Loaf !.

    In fact, we might have to look at this scenario for real in future.

    With regard to the sources of the Wandle, Waddon Ponds is the only one with pure unpolluted water that wells up all year. The Carsghalton Branch only flows naturally in years when the water table rises to the surface. The rest of the time it is fed by a main of recycled water from the Beddington Sewage treatment works near Goat Bridge Hackbrigde

    With regard to the Croydon urban area, I would guess that the smaller “Scar Brook” at Scarbrook Hill stopped flowing when the Victorians started abstracting water with the waterworks in nearby Matthews Yard by Surrey Street.

    Sadly, the underground section of the Wandle from Swan and Sugarloaf along Southbridge Road (the South Bridge on the Wandle) probably only flows when storm water off the road enters the road gullies. Whilst some of the natural fresh ground water in this area might just rise as far as the soil just below the surface, under normal conditions, the water table under the South Croydon valley is normally much lower than it once was, due to abstraction of fresh water that we, the residents of Croydon, drink and flush down the loo.

    Some water emerges into Wandle Park through the culvert, to feed the re-opened section in the park ( I think that Croydon Council have done an excellent job in restoring the river to the open air here) but I have to wonder how pure it is.

    Thankfully, exposure to open air, and the natural gravel of the river bed, and presence of water plants, act to purify the water.

    For urban rivers like the Wandle, water quality is always going to be compromised by road run-off. If only the Government made a commitment to a 50 year programme to keep polluted water out of the Wandle, and treat all incoming waters from roads and dodgy sewers, before discharge into the Wandle, we could have a 100% pure river again, but sadly, under current UK politics, this would be difficult to bring about as the water and sewage companies are privatised.

    However, it’s amazing what can be done with reed beds and gravel riffles to purify the waters, so we need to be positive, and try cheaper solutions. Loyal readers of Inside Croydon might be inspired by the restoration works carried out a few years ago to restore the Quaggy River at Sutcliffe Park Greenwich, and the Ravensbourne in Catford and Lewisham.


  3. RJ Newman says:

    I can tell you exactly where the Wandle was flowing during the floods of 1997 and 2007: in my back door and out of my front door.

  4. Lewis White says:

    Hi RJN. I am very sorry that you have has suffered from flooding. Flood victims like you are often bearing the brunt of bad development decisions made in the past, whether in Victorian times or much more recently. Many decisions were made in good faith, on the basis of recent absence of flooding over the 20th century. Sadly, nature has a habit of bucking the trends, and delivering double flood whammies in short succession– as in recent years.

    It makes very clear that ALL new developments must be sited wisely, away from flood zones. Sadly, local and national Government has, until the last 15 years , given planning permission to new buildings on places that our forefathers and mothers knew intuitively or from experience would get flooded at some time. Why?. Yes, no prizes for sussing out that money talks, and developers like to get houses in where they are given permission. They can’t be blamed for building on land that Government said was OK.

    Thankfully, things have changed, and everyone is far more aware of the foolishness of floodplain development. Hopefully this will minimise the number of future “new” flood victims. Local authorities in the UK are also now working on local schemes to address flood prone spots, so I hope that you might benefit from some such scheme in Croydon.

    Some local flooding is a by-product of people paving over the whole of their front gardens– and the water runs off on top the road outside. In my view, we need effective national legislation and enforcement locally to ensure that porous paving is used in all cases. Yes, unlikely, but every drop of rainwater suoked up by the soil ( rather than discharged on to the highway) is one fewer that might flood someone’s house. Every little helps!

    In fact, it is illegal under the Highways Act to discharge water on to the highway, and has been so for well over 100 years!

    Lewis White

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