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The Clwyd-Powys Archaeological Trust News - old stories

The House Under the Water

The House Under the Water, immortalised in Francis Brett Young’s romantic novel published in 1932, was spectacularly revealed during the drought of the late summer and autumn of 2003 below the receding waters of the Elan Valley reservoirs. Young describes ‘Nant Esgob’, based upon the eighteenth-century mansion of Nantgwyllt, below the Caban-côch reservoir, being submerged below the waters daming up behind the fictitious ‘Cwm Gwilt Dam’: ‘the waters passed on, engulfing step by step, the box-borders, the ragged sward of lawn, the flagged path, till, scaling the threshold at sunset, they crept into the panelled hall, exploring the cracks in the pavement and filling the mice in the wainscot with urgent alarm’. In reality, all the buildings affected by the Elan Valley scheme, which included the early nineteenth-century country house of Cwm Elan, the little church at Nantgwilt, a school, Baptist chapel, and about twenty farm and other buildings, were all demolished before they were reached by the rising waters.


Left: The extensive landscape at Nantgwyllt, normally submerged below the Caban-côch reservoir, includes the remains of the eighteenth-century country house, a walled garden, road walls and road bridge, and the foundations of numerous other buildings and cottages which extends over an area of several hectares. © CPAT 1539-03

The drought of 2003 enabled many of these sites to be recorded during the course of historic landscape characterization work funded by Cadw. Additional fieldwork was undertaken with the help of members of the field section of the Radnorshire Society and some recording from the air was undertaken with the help of funding from the Royal Commission. In addition to Nantgwyllt, exposed remains included the foundations Cwm Elan and the farmhouse at Dol-faenog, both below the Garreg-ddu reservoir, and the foundations of the farmhouse at Ty Nant below the Penygarreg reservoir. Various elements of the construction works were likewise exposed during the drought, notably the mason’s yard and stretches of the former Elan Valley railway to the south-west of Caban-côch dam, and the stone and timber foundations of a workmen’s hut just to the west of the Craig Gôch dam.


Right: Distant view of Craig Gôch dam from the south-east with Penygarreg reservoir in the foreground, seen during a period of low water. The remains of Ty-nant house, demolished to make way for the reservoir and normally submerged below the reservoir, are visible at the bottom left. In the far distance is Esgair Rhiwlan. © CPAT 1528-08

The House Under the Water is by no means the earliest or most illustrious of the Elan Valley’s claims to literary fame. The Romantic poet, Percy Bysshe Shelley, endeavoured with Harriet, his newly-wedded wife, to aquire Nantgwyllt in 1812, to found ‘a little colony of enlightened souls’. ‘Give me Nantgwillt, fix me in this spot, so retired, so lovely, so fit for the seclusion of those who think and feel. Fate, I ask no more!’ In the eyes of some, the association with Shelley is clouded by the fact that his first sojourn in Elan Valley was a consequence of having been sent down from Oxford for espousing aetheism, compounded by his abandonment of Harriet and elopement with Mary Wollstonecraft just two years later. Other poets had been drawn to the dramatic landscape of the Elan Valley before Shelley. William Lisle Bowles’s poem ‘Coombe-Ellen’ (Cwm Elan), published in 1801, begins with an ‘invocation to the spirit of wild untamed Nature’: ‘Call the strange spirit that abides unseen / In wilds, and wastes, and shaggy solitudes’.


Left: In the foreground can be seen field walls the foundations of the former house at Garreg-ddu, below Caban-côch reservoir, which gave its name to the Garreg-ddu viaduct. © CPAT 1526.05

These literary associations were well known when work began on Birmingham’s reservoir scheme and are likely to have subtly influenced various picturesque aspects of its design. Writing in 1894 William Rossetti, perhaps with a vision of Millais’ iconic Ophelia before him, observed somewhat melodramatically that ‘Harriet Shelley died by her own deed in the Serpentine in 1816, Shelley in the Mediterranean waves in 1822; and now a watery doom effaces the scenes of their short-lived love, Nantgwilt and Cwm Elan. A world of waters, a world of death.’ Like the foundations of the houses and gardens revealed as the water levels recede these literary associations provide a significant though often subliminal dimension to this designed landscape of the late Victorian and early Edwardian period.


Right: Entrance through the walled garden at Nantgwyllt, with Caban-côch dam in the far distance. In normal years this wall is entirely under the water, like the rest of the former gardens of Nantgwyllt © CPAT 1539.13b

The Elan Valley historic landscape is defined in the Register of Landscapes of Special Historic Interest in Wales, of which details can be found on the website of the Countryside Council for Wales ( The excellent Powys Digital History Project website ( makes available an extensive archive of photographs and drawings about the construction and opening of the reservoirs. A report on historic landscape characterization in the Elan Valley will appear on the CPAT website in due course. This year marks the Centenary of the opening of the reservoirs by King Edward VII, two years before the works themselves were completed.

Bill Britnell, February 2004

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