The Elan Valley Dams

The engineering is Victorian municipal confidence at full stretch, and it is worth being clear-eyed about both halves of that.

Birmingham's population had grown enormously and its water was inadequate. The Birmingham Corporation Water Act of 1892 gave the city the Elan and Claerwen valleys, twelve miles west of Rhayader, on the grounds that they were high, wet, geologically suitable and thinly populated.

The scheme

Four dams went up between 1893 and 1904: Caban Coch, Garreg Ddu, Pen y Garreg and Craig Goch, in a chain up the Elan. Edward VII opened them in July 1904. Claerwen, in the adjacent valley, was added in 1952 and is much the largest.

The design is deliberately architectural. Masonry rather than earth, with balustrades, corbelled overflows and a submerged dam at Garreg Ddu carrying a road across on arches. Water pours over the crests in a sheet when the reservoirs are full, which was an intended effect.

The aqueduct runs 73 miles to Frankley outside Birmingham and works entirely by gravity, dropping about a foot every two miles. It has never needed pumping and it is still in service.

What went under

Farms, a school, a chapel, and two country houses, Cwm Elan and Nantgwyllt.

Percy Bysshe Shelley stayed at Cwm Elan in 1811 and tried to buy Nantgwyllt two years later, which is why the drowning of these valleys turns up in literary biography more often than the drowning of Llanwddyn does.

Around a hundred people were displaced. Landowners were compensated; tenants and labourers were treated very much less generously, and several accounts record that they simply left the district. In drought years the gable of Nantgwyllt appears above the falling water, which draws visitors and is a fairly blunt reminder.

A purpose-built village housed the construction workforce, which ran into the thousands at peak, with its own hospital and school and a compulsory bath house. Then it emptied.

Why there was no outcry

Compare Tryweryn in the 1960s, which became the defining Welsh political grievance of the century. Elan produced almost nothing comparable, and the differences are timing, language and law: in the 1890s there was no Welsh national political movement with the reach to run a campaign, Radnorshire had almost no Welsh-language press, and a private Act of Parliament settled the matter as a question of property rather than of community.

Now

The estate runs to around 45,000 acres and is managed by Welsh Water for access, conservation and supply together. It is open in a way very little Welsh upland is, with a visitor centre, waymarked trails and a traffic-free route along the old Birmingham Corporation railway.

It is also an International Dark Sky Park, which on a clear night is worth the drive on its own.

Red kites survived their near-extinction in Britain in exactly this country, a handful of pairs in the Elan and Wye valleys. The feeding station at Gigrin Farm near Rhayader now draws several hundred birds daily.

Visiting

Free, open, with parking and a visitor centre near Caban Coch. The road up the valley is single track in places.

Go after heavy rain if you want the dams overflowing, and in a dry summer if you want to see what is underneath.