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Into the valley

Caban Coch dam holds 35 million cubic metres of water but is built of local stone meaning it doesn't appear out of place Caban Coch dam holds 35 million cubic metres of water but is built of local stone meaning it doesn't appear out of place Stephen Clarke
20 Jun
In this month's RGS-IBG Discovering Britain walk Tom Hart finds England's second city relies on a dam built in a Welsh valley

For more great walks, trails and viewpoints, be sure to check out the new Discovering Britain Facebook page by clicking here.

Discovering BritainThere’s a bit of Birmingham in the Welsh valleys. It’s a hundred-mile car journey from the Midlands to the mid-Wales beauty spot known as Elan Valley, and it’s here that Birmingham’s engineers came to find a fresh and incredibly soft water supply for the city.

‘It’s one of the things you actually get used to living in Birmingham. Being born a Londoner, every time I had a bath I would use a quarter of a bar of soap, but if you do that in Birmingham you just end up with soap suds in your eyes,’ says Martin Haslett, who developed this Discovering Britain walk around the Elan Valley and its lowest dam, Caban Coch.

Haslett first visited the Elan Valley as a child, not suspecting that years later he would drink and bathe in Elan water when he moved to Birmingham to work as a town planner.

‘I suppose there were fewer visitors in the 1960s. There weren’t many people there whereas now it is a tourist site, but really otherwise nothing much had changed,’ he says.

As Birmingham grew in the late 1800s the city’s water supply came under increasing pressure. ‘It’s a common thing in mid-Victorian times. There were often outbreaks of cholera. Birmingham was no exception,’ says Haslett.

In 1800, Birmingham had around 70,000 inhabitants. This had grown to more than 500,000 by 1900, all of them needing water. While many focused on how London sought out fresh supplies, it was often forgotten that all growing industrial cities needed to improve their water. ‘In mid-Victorian times, people were saying they didn’t have to put up with this neglect and a lot of cities were looking to the uplands to find good water,’ says Haslett.

The city purchased 18,400 hectares around the River Elan to construct six dams and a reservoir system, with work starting in 1893. Elan was chosen for its regular heavy rainfall, and geographical position relative to Birmingham. A slight downwards incline allowed the water to flow 73 miles to the city without pumping.

‘You think of dams, and you think of a lot of concrete, but these were works of art in themselves,’ says Haslett.

Flooding the valley for Birmingham’s supply did not come without a human impact. More than 100 people had to leave Elan to make way for Birmingham’s water

Caban Coch dam, completed in 1904, provides the route for this walk. At 36 metres high and 186 metres wide, the dam holds 35 million cubic metres of water. But the vast structure is not alien to the landscape. It is the landscape – the builders used dressed local stone to build the dams around Elan.

Constructed at the valley’s narrowest point, Caban Coch was built with impermeable stone placed in concrete. The concrete cake mixture was then used to plug the river’s route.

A scarred cliffside car park marks the quarry’s location and a walk along the disused railway line reveals a wooded landscape that’s perfect for filtering sediment before it reaches the reservoir. It’s also an ideal habitat for owls. At night the birds’ calls echo across the empty valley.

A Baroque extraction tower pulls water from the reservoir to begin its journey to Birmingham. While the dam itself blends into the Welsh landscape, the support system for the reservoir grafts Birmingham on to Wales.

‘It’s all Birmingham Corporation Water Works on all the old signs. The buildings are all Birmingham-style. There’s very little Welsh in them at all,’ says Haslett. The only difference is that in Birmingham the same architectural style – Birmingham Baroque – uses red bricks and not the grey local stone. For any visitor from the Midlands’ city, it is almost certain to be an uncanny experience.

Flooding the valley for Birmingham’s supply did not come without a human impact. More than 100 people had to leave Elan to make way for Birmingham’s water.

On one visit to Elan, Haslett had a surprise encounter. ‘Somehow the organisers had managed to find the relations or grandchildren of the original owners of a farm [in the valley]. I remember thinking this wasn’t going to go very well because they weren’t going to like Birmingham very much,’ he says.

There was no bitterness from the descendents, however, perhaps because the city did its best to make life easier for those it had displaced.

‘I think Birmingham worked very hard to build up a good relationship. They used to send a coach every year to take children to the pantomime,’ says Haslett.

Water is a political issue, whether it’s in the Middle East or the Welsh valleys. At one time there was Welsh nationalist sentiment that favoured Welsh water for Welsh people, with tensions particularly high over dam projects to provide water for Liverpool.

The aqueducts that funnel the water to Birmingham were not marked on OS maps, according to Haslett. ‘I think it was more to do with Welsh extremists. Birmingham gets its lovely water and Wales loses some. But it is run by Welsh Water now so I think that helped to ease that problem because Welsh Water now sells the supply to Severn Trent,’ says Haslett.

walesThe picturesque Elan Valley reservoirs still provide Birmingham with its water supply (Image: David Hughes)

A small church has been constructed to replace one lost in the valley. The visitor’s book is studded with tributes to the church’s peacefulness. And there’s a stillness to it that matches the reservoir waters outside.

Beyond it, the woodlands end abruptly, as if a razor has been run down the hillside.

‘We’ve suffered from a lack of wood[land] through the early parts of the 20th century,’ says Haslett. Very well-ordered plantations result from efforts to re-wood the landscape. ‘You can contrast that with large areas, where there are scrubby short trees,’ says Haslett.

The River Elan still flows through the Caban Coch dam, supplying water for southeast Wales. Keeping a sustainable water supply was already a priority for the dam’s engineers. ‘If you cut the river off there’s not going to be a supply,’ says Haslett. It’s not only water the dam supplies, of course, but also electricity for the National Grid, around 11 million kWh per year.

Beneath the dam is a barred suspension bridge with peeled paintwork. This was the checkpoint to the dam worker’s village, which was guarded to keep out ‘unsuitable night workers’. The 11-year project used 50,000 men, and Birmingham wanted them all in good health.

The houses were temporary wooden buildings, but a small permanent village for the workers who maintained the dam still exists. Again, it’s built in the Birmingham style. ‘If you look through the village it is built from local stone, but the actual designs you would find in Birmingham in the prosperous garden villages,’ says Haslett.

Near the workers’ village is a small dam that used to supply the village with water. Long hidden among trees, the site is now more visible thanks to a clearance project by Welsh Water. It was here that large-scale destruction was planned in miniature. ‘I hadn’t come across this, but it was an ideal design for Barnes Wallis to test his bombs,’ says Haslett.

Further along the route, another replacement chapel houses the old graveyard from the drowned community. An old railway line now turned into a cycle route runs past the church. A branch off this path leads to a camouflaged aqueduct that runs across a narrow valley above Llanfadog Farm. The disguised aqueduct, which could just be an unusually positioned rural bridge, fits with the Elan Valley’s natural engineering. ‘I suppose the fact that we can make use of the countryside and yet still leave it looking beautiful is probably the watchword,’ says Haslett.

Once the visitor centre shuts for the day it quickly becomes clear how isolated the Elan Valley is from the world

When the water first flowed from the reservoir the prediction was that it would take exactly seven days to reach the reservoirs on Birmingham’s outskirts.

‘It is a very slow gradient, but the engineers were able to predict when it would arrive, and they were spot on. So it’s a tribute to the Victorians,’ says Haslett.

Before the water heads for Birmingham, a treatment works hardens the exceptionally soft water. Water was once passed over a chalk bed, but this process has now been substituted with a chemical treatment. The plant also removes sediment and other materials by passing the water over sand and shingle.

Beyond the treatment plant is a road that leads to the other dams and reservoirs, each a beautiful construction in their own right and a spectacular sight when the reservoirs are full to overflowing and the water is cascading down the dam face. Stone blocks on the face’s surface creates a strange whiteness.

‘You can’t help but feel that the engineers, when they put those blocks there, were thinking about how beautiful it would be,’ says Haslett.

‘You need a wet summer with a really sunny day though,’ he advises.

The Elan Valley visitor centre sees 200,000 visitors each year, but aside from the cascades over the dams, the site is most spectacular at night. Once the visitor centre shuts for the day it quickly becomes clear how isolated the Elan Valley is from the world.

There’s nothing to hear but bird cries in the distance, and the water flowing through the dam and on to the towns and villages below.

Overhead, if the weather is clear, the sky is filled with zig-zagging satellites, and at the right time the International Space Station provides a steady light, which looks as natural in the sky as the dams in the Elan Valley.

WALK Details
• Location: Wales
• Type: Rural
• Distance: 6 miles
Click here for more details

Unearth more of our nation’s history and find more great walks, trails and viewpoints around the UK at discoveringbritain.org or via the new Discovering Britain Facebook page.

This was published in the June 2015 edition of Geographical magazine.

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