Welsh dams that helped save Birmingham will be 120

It is 120 years since four impressive dams were built in Mid Wales to supply clean water to polluted and fast-growing Victorian Birmingham.

Opened by King Edward VII in 1904, the Elan Valley dams have since held back 50 million cubic metres of water – about 20,000 Olympic-sized swimming pools.

The structures near Rhayader in Powys, which now also supply water to mid and south Wales, have stood the test of time and are now an integral part of the region’s landscape.

“They will outlive us all. We expect they will still be here for the next 120 years,” said Jen Newman, Elan Valley expert at Welsh Water.

The four dams Craig Goch, Garreg Ddu, Pen y Garreg and Caban Coch were built by the Birmingham Corporation Water Department from 1893 onwards.

The Elan Valley site was chosen by Joseph Chamberlain, father of future Prime Minister Neville Chamberlain, who was elected Mayor of Birmingham in 1873.

“Birmingham experienced a massive industrial revolution and a huge population boom, but there were no major rivers flowing into the city,” explained Ms Newman.

“There were smaller rivers and they became polluted very quickly, so diseases were widespread: dysentery, diarrhea and all the usual diseases.

“Joseph Chamberlain knew that to save his city, he had to get clean water to it, and fast.”

Once the site was found, the company was able to acquire the Elan Valley through a compulsory purchase pursuant to an Act of Parliament in 1892.

What was good for the people of Birmingham was, however, less beneficial for the local population.

“The people in the village had no say,” Glyn Webster of the Elan Valley Visitor Centre told the BBC earlier.

Two large mansions and about 44 properties were demolished, including 18 farms, a small mill, a school and a church.

“About 100 people had to move,” Mr Webster said.

“Most of the villagers were tenant farmers and only the landowners received little compensation.”

Ms Newman said the site was chosen because it was almost the “perfect location” for such a project.

There was plenty of rainfall, the riverbed was made of the right rock, and the valleys were beautifully narrow – ideal for a dam, or four, according to Mrs Newman – and apparently Mr Chamberlain too.

In just over ten years, the four dams were built and the water began to slowly flow into the central plateau.

“The pipeline is ridiculous,” Ms. Newman said.

“It is approximately 70 miles (112 km) long and runs from the Elan Valley to Frankley Reservoir in Birmingham… entirely by gravity.”

“The gradient is 1:2,300, which means there is a one centimeter drop every 23 meters… it trickles at about 1.6 km/h and takes three days to get there.”

In addition to their practical uses, each of the four dams attracts thousands of tourists and regularly appears on thousands more Instagram feeds.

Civil engineer James Mansergh, who Ms Newman says is “not celebrated nearly enough,” was chief planner of the project.

“He built the dams not only to hold back the water, but also to build them beautifully,” she said.

“The style is called Birmingham Baroque, a kind of Gothic style. You’d think it came from some kind of Hound of the Baskervilles.

“We built these towers with the copper-colored green roofs that have become a kind of icon.”

Ms Newman estimates that the dams attract around half a million people to Rhayader and the surrounding area every year.

“Rhayader is such an amazing community of people who are so proud of the dams and the Elan Valley. It’s a really important part of their tourism,” she said.

“I love it when the dams overflow, like all the others, and everyone flocks here.

“I’m pinching myself a little bit that I get to work in such a beautiful area.”