Creeping disaster of centuries of over-reliance on chalk streams in Cambridge revealed in new film

Cambridge’s water supply issues began 400 years ago when the chalk streams were first diverted into the city – and inept management means that the region is now sleep-walking into a water supply disaster, says Tony Eva, the writer and producer of a new film about the crisis titled Pure Clean Water.

The just-released trailer for the film, which received more than 5,000 views in its first 48 hours, considers the near impossibility of the region being able to retain its own water supply in the longer term.

Tony, a Cambridge-based campaigner and filmmaker, started working on the project in 2019.

“It was a hot dry summer,” he says, “and that was when it became apparent there were some real problems with our chalk streams.

“They call it a creeping disaster because it doesn’t happen overnight. It takes years, decades, but it became very obvious in 2019. Someone called the council and Cllr Katie Thronburrow called a meeting at the Guildhall.

“I popped in and was absolutely gobsmacked about the state of our chalk streams. I was very ignorant about them, and I made a vow to myself to find out more.”

The first port of call was Hobson’s Conduit, also called Hobson’s Brook, a watercourse built between 1610 and 1614 by Thomas Hobson to bring fresh water into the city from springs at the Nine Wells nature reserve near Great Shelford. Nine Wells feeds Hobson’s Conduit its water.

In 1614 drinking water was piped from the conduit head to a new fountain in Market Hill. In 1631 another supply was drawn from the conduit head for Emmanuel College and Christ’s College. The conduit also supplies Cambridge University Botanic Garden.

More pumping engines were added in the 1850s. Cambridge University and Town Waterworks was established in 1853. Thus began the new era of piped water supply. From then on those who could afford it had water piped into their homes, rather than walking to the market with a bucket.

The water supply to the fountain in the popular city market was eventually switched off in the 1970s.

“Obviously there is no water in the fountain in the market square today and I wondered why,” continues Tony. “The simple answer is that during the construction of Lion Yard car park in 1970 the fountain was turned off.

“But the water level was already very low. There were complaints from Emmanuel and Christ’s that there wasn’t enough water: they had swimming pools in their colleges at that point. So the council decided to turn the fountain off in 1971.

“If there had been a good supply of water at that time, that link would have continued and we’d still have water flowing in the fountain.

“So the question then is, why was water pressure so low in the early 1970s? The answer is that in 1961 they’d opened a pumping station at Babraham – this was pre-privatisation.”

The UK’s water supply was run by publicly-owned water boards until 1989, when the sector was privatised.

“The new station at Babraham had a dramatically negative effect on the outflow at Nine Wells which feeds Hobson’s Conduit,” continues Tony. “So problems with water flow in Cambridge go right back to the 1970s.

“During the 1976 drought Nine Wells dried up, probably for the first time in 8-10,000 years. Water was being pumped from underground and it couldn’t take the combination of abstraction and drought: the effect on wildlife was catastrophic.”

The Pure Clean Water trailer asks: “Is the Cambridge growth phenomenon about to be derailed by a shortage of water? For hundreds of years a chalk stream, diverted into the town centre, provided Cambridge with drinking water. It was a hugely successful public health initiative, supported by both town and university.”

And indeed in the 17th century the city managed to shed the burdens of water-borne diseases such as typhus and dysentery, but the solution was only temporary – even if it lasted for 400 years. Now people are – excuse the pun – kicking up a stink about the state of the Cam, the volume and frequency of sewage discharges into rivers and coastline, and the failure to update the Victorians’ sterling infrastructure efforts.

However, the privatisation of water in the UK in 1989 isn’t likely to be undone any time soon, so what hope is there for the future?

“There’s no mood to unprivatise the water companies right now,” accepts Tony, “but everybody gets water, everybody gets the idea of a dried-up stream, and everybody gets the idea of children being able to play in water and fish being in the water. If the public start telling politicians they have to address the issue then there is a chance.”

But the politicians aren’t listening, so what happens next?

“Well, when people start turning their taps on and no water comes out they’ll say why wasn’t something done about it?”

The chairman of Hobson’s Conduit Trust, John Latham, portrays a city incapable or unwilling to adapt.

“Cambridge claims to be a seat of learning, with a strong repository of knowledge about ancient civilisations,” he said. “How ironic therefore that we lost sight for decades of what the Greeks and Romans, and indeed the Victorians knew - that no viable growing city can exist without an adequate water supply, which may well necessitate significant and costly engineering. A seat-ofthe pants approach to water supply is wholly inexcusable in a city such as Cambridge.

“The City’s still utterly lamentable decision to destroy the historic core buildings around Lion Yard and replace them with what remains the - to put it very kindly - mediocre architecture of the uninspiring parade of modern shops went right over the the pipeline from the Conduit Head which ran under what is now Lion Yard to the marketplace.

“I think that the irrefutable issue is that we, collectively, in the Cambridge Water supply area, are utterly over-reliant on chalk aquifer water. This is why growth here must not be allowed to continue at the current or projected rateunless and until alternative sources of public water supply are secured and put in place for the CWC supply area.

Pure Clean Water started off as a 10-minute short.

“The original plan was to make a short documentary about Hobson’s Conduit,” says Tony, who chairs the Friends of Logan’s Meadow group. “Then I met Nigel Kinnings through a friend. He’s a very experienced camera operator with a strong TV background and he suggested this could be a larger project and was happy to help out, which was fantastic.

“Then of course when you start interviewing people and the story goes where the interviewees take you, and the story – it turned out – was not about Hobson’s Conduit but about the over-abstraction of water in Cambridge, so it snowballed from a 10-minute film to a project with over a dozen people including Cambridge Water, colleges, historians, campaigners, academics, trusts – a good range of people and expertise.

“We’ve got a rough cut of the film finished, it’ll take a couple of months to knock it into shape. The idea is to have a campaigning film with a launch event and a Q&A and a discussion, because the only way the issue can be resolved is through action, and the community needs to be involved.

“Hopefully it’ll get shown at the Cambridge Film Festival, there’s no guarantee but if they do a viewing it’s a prestigious event and it’ll get the conversation going to show to politicians that people are really concerned.”

Pure Clean Water is due to go on general release in October.