Crai Reservoir (also known as Cray Reservoir) is a storage reservoir located in the Brecon Beacons National Park (named after the village of Crai) for the water supply to the city of Swansea in South Wales and was built between 1898 and 1908 by Swansea Corporation.
The reservoir now supplies water to the towns in the valley of the River Tawe and north Swansea.
The reservoir is one of several established in what is now the Brecon Beacons National Park, an area of Old Red Sandstone peaks with relatively high rainfall.[1] The 28-metre high dam is within a wide glaciated valley and is estimated to impound some 1,007,000,000 gallons of water. The structure is believed to have been made from over 10 million bricks.
Upstream of Crai Reservoir the land is largely upland moorlands or unimproved grassland with one area now given over to coniferous forestry. The impounded water quality is good and the water requires only minimal treatment before entering the water supply system. The treatment of screening, disinfection and lime dosing is carried out south of the reservoir at Nant yr Wydd.
Despite the generally excellent quality of the water, there have been occasional episodes of impaired quality mostly concerned with forestry planting and the release of difficult to treat turbidity into the reservoir. On occasions when such raw water quality impairment has overwhelmed the treatment facilities, some bacteriological deterioration has been experienced in the downstream water supply system such as in 1981.[2]
Plaque
Face of the dam
^"Wales: climate" (PDF). Met Office. Retrieved 21 June 2020.
^Water Supply and Forestry, a conflict of Interests - Cray Reservoir - a case study - C Stretton
CraiReservoir (also known as Cray Reservoir) is a storage reservoir located in the Brecon Beacons National Park (named after the village of Crai) for...
as Blaen-crai flow north from Bwlch Bryn-rhudd, a col between the Crai valley and the upper Swansea Valley for 2 km into the Cray Reservoir. The river...
overlooking Stone Canyon Reservoir. Page two of Sunset Express, a 1996 detective novel by Robert Crais, is set by the reservoir. The 55-mile-long Mulholland...
summit plateau. The hill drains to the north into the catchment of the Afon Crai and to the south and west into that of the River Tawe. Fan Fraith is a nearby...
Inscriptions et Belles-Lettres (in French), 132 (2): 361–380, doi:10.3406/crai.1988.14616 "President al-Assad awards Italian archaeologist Paolo Matthiae...
block and occupies the ground south of the Usk valley and to the west of Crai which rises to Moel Feity. The smaller central block (51°55′37″N 3°42′04″W...
the boundary between Carmarthenshire and Powys, it flows north into Usk Reservoir, then east by Sennybridge to Brecon before turning southeast to flow by...
and Fan Llia as Ystradfellte Reservoir. The headwaters of the northerly-flowing Afon Crai are stored in Cray Reservoir immediately west of the A4067...
Afrique proconsulaire : de l'agglomération numide à la ville africo-romaine », CRAI, 2003, pp. 131-155 Mustapha Khanoussi, « L'évolution urbaine de Thugga (Dougga)...
Llwch Afon Ysgir (L) Nant Brân (L) Afon Cilieni (L) Afon Senni (R) Afon Crai (R) Afon Hydfer (R) River Wye (Afon Gwy) River Trothy (R) River Monnow (Afon...
origin for Croydon in the form "Crai-din" meaning "settlement near fresh water" (cf Creuddyn, Ceredigion), the name Crai (variously spelled) being found...
off the road from Bwysfa fawr near Trecastle on the way to Belfont farm Crai. There now is a large water tank on the place where the farm stood, which...
is the pass of Bwlch Bryn-rhudd over which the A4067 road runs from the Crai valley south to that of the Tawe. Cefn Cul is formed from sandstones and...
Inscriptions et Belles-Lettres (in French), 132 (2): 361–380, doi:10.3406/crai.1988.14616 Wilkinson, Tony J. (2004), On the margin of the Euphrates. Settlement...
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Plaque
Face of the dam
