The battle to save England’s chalk streams, one of the planet’s rarest habitats

The battle to save England’s chalk streams, one of the planet’s rarest habitats

Conservationist Allen Beechey remembers a time, in the 1990s, when trout swam along the River Chess as it meandered through the centre of his home town of Chesham. “It was a gentle, reassuring sight and it helped trigger my love of nature,” Beechey said last week.

Then came the droughts, the river dried up – sometimes for several years at a stretch – and the fish died out. They have yet to come back to the Buckinghamshire town.

But Beechey has a dream that one day trout will return to this part of the river, which is one of most important chalk streams in England. It would be a signal that this critically important but highly endangered habitat was returning to good health after years of damage caused by increasing water abstraction and other threats.

Jake Rigg, of Affinity Water, on left, and Allen Beechey, by the River Chess.

These hopes were raised recently when the local water company, Affinity, announced it had stopped abstracting water from the Chess. Previously it had been taking out about 6m litres a day from the river from two pumping stations at Chesham and Chartridge, a nearby village. This abstraction has now been halted and water for the region is now being piped in from other areas of southern England, including regions close to the Thames.

“We have reconfigured our network to bring in water from elsewhere and although this costs quite a bit of money, we recognise it is important to save this precious habitat,” said Jake Rigg, the head of corporate affairs and communities at Affinity Water.

Chalk streams are some of the planet’s rarest habitats and 85% of them are found in England. Of the 260 true chalk streams on Earth, 224 of them run through the English countryside, as listed in the WWF State of England’s Chalk Streams report of 2014, a reflection of the nation’s geology and its temperate climate. (France accounts for most other chalk streams including the Somme.) These streams emerge from underground chalk aquifers and typically flow over flinty gravel beds. This ensures their cleanliness but also endows them with dissolved iron and magnesium minerals.

Aquatic plants such as Flag Iris and Water Crowfoot thrive on their banks; the brilliant sulphur coloured Yellow Dun Mayfly and Green Drake Mayfly flourish in their ultra-clean waters; while otters, kingfishers and water voles make their homes there. They are the embodiment of the tranquillity of the English countryside. Kenneth Grahame’s Wind in the Willows unfolds around a chalk stream; Wordsworth, Rupert Brooke and Tennyson expressed their love of them; while Sir John Betjeman wrote of one, the Kennett: “When trout waved lazy in the clear chalk streams, Glory was in me …”

But like other rare habitats such as the rainforest and the coral reef, the chalk stream is also suffering from environmental threats – with two particular menaces causing most worry.

“First of all chalk streams are being drained of water by companies trying to meet the nation’s increasing thirst,” said Beechey, who manages the Chilterns Chalk Streams Project. “This process began in earnest in the 70s as more and more homes were being built in and were being fitted out with dishwashers, showers, washing machines and other domestic appliances.”

These devices have helped to cause a 70% increase in household water use since 1985 in the UK and, as a result, abstraction rates have soared across the country – including those from aquifers in the Chilterns, which is home to some of the country’s finest chalk streams. This led to the drying out of rivers and streams that began in the 90s and struck Chesham in 1997.

But abstraction is not the only problem. “There is also the impact of global warming which is triggering more and more heatwaves that in turn are helping to dry out streams,” added Rigg.

This threat is now becoming a major concern after the Met Office warned recently that over the next five years there was now a 40% chance that global temperatures will reach 1.5?C above pre-industrial levels, the upper limit that climate scientists want to set for the warming of our planet.

In recent years, rising numbers of heatwaves have led to increasing numbers of chalk streams being drained dry in many places. Overall, fewer than a fifth of all England’s rivers are now considered to be in a healthy condition.

The ruins of Cannon Mill on the River Chess.

It was against this worrying backdrop that the Chiltern Chalk Stream Project and local community groups began talks with Affinity Water with the aim of halting abstraction of water from the River Chess – resulting in the decision to halt abstraction around Chesham. Last week, the crystal waters of the Chess poured through the town, glittering in the sunlight.

A great deal still needs to be done to save the Chilterns’ chalk streams, however – a point stressed by Beechey. “The abstraction around Chesham is only one part of the story. The Chilterns have one of the highest rates of water use in the country – about 170 litres per person per day – and we need to cut that down. In addition, no reservoir has been built in the south-east since the 1970s. We need investment. People assume water will always be cheap, clean and on tap. But there is a limit.”

A measure of the vulnerability of chalk streams was illustrated by the 2019 drought which dried out 67% of those in the Chilterns. These punishing cycles of water loss are killing off vulnerable wildlife. “The end of abstraction around Chesham is a signal that we can do something but a lot more needs to be done by water companies and the government – and they need to do it quickly,” added Beechey.

“To do nothing would be the equivalent of letting rainforests be chopped down at their current rate or letting coral reefs be slowly eroded without trying to save them. Chalk streams are a quintessential component of the English countryside and we need to fight to save them.”

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