Claerwen Fault

The Claerwen reservoir and dam in Powys, Wales, were the last additions to the Elan Valley Reservoirs system built to provide water for the increasing water demand of the city of Birmingham and the West Midlands. The dam is built mainly of concrete, with the exterior dam face in dressed stone. The dam is a gravity dam built upon solid rock foundations as the pressure of the reservoir behind should be in equilibrium with the total weight of the dam itself thus causing complete stability. The Claerwen dam was finished in 1952 and was given a late Victorian effect so that it blended in with the earlier dams in the valley. It was necessary to employ the services of Italian stonemasons as British ones were still at work in London during the post-war rebuilding process of the late 1940s. The dam took six years to complete and was almost twice the size of the other dams in the Elan valley. The Claerwen reservoir is almost the size of all the other reservoirs in the Elan Valley system combined. Officially commissioned by Queen Elizabeth II in 1952, it was one of her first royal engagements as monarch. Water from the reservoir flows via an underground aqueduct to the Caban-coch reservoir from which it is abstracted through a gravity aqueduct to Birmingham.

The Elan Valley Reservoirs (Welsh: Cronfeydd Cwm Elan) are a chain of man-made lakes created from damming the Elan and Claerwen rivers within the Elan Valley in Mid Wales. The reservoirs, which were built by the Birmingham Corporation Water Department, provide clean drinking water for Birmingham in the West Midlands of England. The five lakes are known as the Claerwen, Craig-goch, Pen-y-garreg, Garreg-ddu, and Caban-coch.Water from the reservoirs is carried by gravity to Frankley Reservoir in Birmingham via the Elan aqueduct. Pumping is not required because the network drops 52 metres (171 ft) along its 73 miles (117 km) length from its source to Frankley. A gradient of 1:2300 maintains a flow of less than 2 miles per hour (3.2 km/h); water takes one and a half to two days to reach Birmingham. The aqueduct, which was started in 1896 and opened in 1906, crosses several valleys and features numerous brick tunnels, pipelines, and valve houses.Work to build the Elan Valley reservoirs was undertaken because the rapid growth of the industrial city of Birmingham in the late 19th century had led to a lack of available clean water. Numerous outbreaks of disease prompted Birmingham City Council to petition the British government which passed the Birmingham Corporation Water Act in 1892. It allowed the corporation to acquire by compulsory purchase all the land within the water catchment area of the Elan Valleys. Thousands of navvies and their families lived in the purpose-built Elan Village during the construction of the first four dams at the turn of the 20th century. In 1952, the Claerwen dam was opened by Elizabeth II in one of her first official engagements as monarch. Drinking water from the Elan Valley is noted for being exceptionally soft, contrasting with water from local supplies in the West Midlands, not served by the Elan aqueduct, which are noted for hardness.The reservoirs are now owned and managed by Dŵr Cymru Welsh Water. The water filtration works further down the valley is run by Severn Trent Water.

The Craig Goch Dam, often called the Top dam, is a masonry dam in the Elan Valley of Wales and creates the upper-most of the Elan Valley Reservoirs. Construction on the dam began in 1897, and it was completed in 1904. The primary purpose of the dam and the other reservoirs is to supply Birmingham with water. In 1997, a 480 kW hydroelectric generator began operation at the dam.

The Elan Valley (Welsh: Cwm Elan) is a river valley situated to the west of Rhayader, in Powys, Wales, sometimes known as the "Welsh Lake District". It covers 70 square miles (180 km2) of lake and countryside. The valley contains the Elan Valley Reservoirs and Elan Village, designed by architect Herbert Tudor Buckland as part of the same scheme. Elan Village is the only purpose-built Arts and Crafts "Model Village" in Wales. It is also famous for its picturesque scenery. Over 80% of the valley is designated as Sites of Special Scientific Interest, and a popular cycle trail, the Elan Valley Trail, makes a loop from Rhayader around the reservoirs. Part of the trail overlaps with a spur of National Cycle Route 81 (Lon Cambria). As of 2015 it is an International Dark Sky Park.

The Principality of Wales (Welsh: Tywysogaeth Cymru) was originally the territory of the native Welsh princes of the House of Aberffraw from 1216 to 1283, encompassing two-thirds of modern Wales during its height of 1267–1277. Following the conquest of Wales by Edward I of England of 1277 to 1283, those parts of Wales retained under the direct control of the English crown, principally in the north and west of the country, were re-constituted as a new Principality of Wales and ruled either by the monarch or the monarch's heir though not formally incorporated into the Kingdom of England. This was ultimately accomplished with the Laws in Wales Acts 1535–1542 when the Principality ceased to exist as a separate entity. The Principality was formally founded in 1216 by native Welshman and King of Gwynedd, Llywelyn the Great who gathered other leaders of pura Wallia at the Council of Aberdyfi. The agreement was later recognised by the 1218 Treaty of Worcester between Llywelyn the Great of Wales and Henry III of England. The treaty gave substance to the political reality of 13th-century Wales and England, and the relationship of the former with the Angevin Empire. The principality retained a great degree of autonomy, characterized by a separate legal jurisprudence based on the well-established laws of Cyfraith Hywel, and by the increasingly sophisticated court of the House of Aberffraw. Although it owed fealty to the Angevin king of England, the principality was de facto independent, with a similar status in the empire to the Kingdom of Scotland. Its existence has been seen as proof that all the elements necessary for the growth of Welsh statehood were in place.The period of de facto independence ended with Edward I's conquest of the principality between 1277 and 1283. Under the Statute of Rhuddlan, the principality lost its independence and became effectively an annexed territory of the English crown. From 1301, the crown's lands in north and west Wales formed part of the appanage of England's heir apparent, with the title "Prince of Wales". On accession of the prince to the English throne, the lands and title became merged with the Crown again. On two occasions Welsh claimants to the title rose up in rebellion during this period, although neither ultimately succeeded. Since the Laws in Wales Acts 1535–1542, which formally incorporated all of Wales within the Kingdom of England, there has been no geographical or constitutional basis for describing any of the territory of Wales as a principality, although the term has occasionally been used in an informal sense to describe the country, and in relation to the honorary title of Prince of Wales.

Elan Village (Welsh: Pentre Elan) is a small purpose-built community in Powys, Wales. It was designed by architect Herbert Tudor Buckland as part of Birmingham Corporation's scheme to construct a series of water supply reservoirs in the Elan Valley between 1892 and 1904. It housed workers and their families responsible for maintaining the scheme's dams and the filtration systems. Elan Village is the only purpose-built Arts and Crafts "Model Village" in Wales. It is served by the B4518 road which runs three miles southwestwards from Rhayader to end at the village, though continuing as a minor road to Caban-coch Reservoir. The road continues over the Elenydd to Cwmystwyth and a cul-de-sac branch runs to the dam of Claerwen Reservoir. It is in the community of Rhayader.

Caeau Cnwch a Ty'n-y-graig is a Site of Special Scientific Interest in Brecknock, Powys, Wales. It occupies sloping ground on the south west side of Pen-y-garreg Reservoir in the Elan Valley. Caeau Cnwch a Ty'n-y-graig comprises four traditionally managed fields in a small valley below Craig Cnwch, near Elan Village. They provide a type of herb-rich grassland that is characteristic of the upland fringe of central Wales.

Carn Gafallt is a Site of Special Scientific Interest in Breconshire, Powys, Wales, and a hill of 466 metres (1529 feet) which is a Marilyn.

Marteg Halt railway station was a station to the northwest of Rhayader, Powys, Wales. The station closed in 1962.

Garreg Lwyd is a hill in Mid Wales, between the towns of Rhayader and Llangurig. It rises to the east above the A470 as it follows the Wye Valley. The Bryn Titli Wind Farm is situated on an area of flatter moorland to the north-west. Red kites frequent the area.

Beulah is a village in southern Powys, Wales, in the community of Treflys, lying on the Afon Cammarch. The village sits astride the main A483 road about 8 miles south-west of Builth Wells and is 49 miles (79 km) from Cardiff and 154 miles (248 km) from London. It benefits from both a pub and service station with attached shop. The parish church Eglwys Oen Duw ("Lamb of God"), built in 1867, can be found 1 mile to the north-west of the village.

The Afon Marteg is a river in Powys, Wales. It is about 15 km long, flowing roughly south-west to join the Wye at Pont Marteg (grid reference SN952714) about 5 km above Rhayader.Fishing is available, with appropriate permits, for brown trout, chub, dace, grayling and pike. The river has a run of spawning Atlantic salmon in the autumn.