The River Tawe flows from its source in the red sandstone hills of the Forest Fawr region of the Brecon Beacons in a more or less south-westerly direction, meeting the sea at Swansea Bay and the Bristol Channel.
Passing through a number of towns and villages including Ystradgynlais, Ystalyfera, Pontardawe and Clydach, the only large tributary is the River Clydach.
The lower part of the valley was intensely industrialised in the 18th and 19th centuries by coal mining and copper, lead, nickel and zinc refining and working and to a much lesser extent by porcelain manufacture.
By weight, more coal than copper ore is needed for the process of smelting copper from the ore, so it is more economical to build the smelter near the coal source. Swansea had very local mines, a navigable river, a nearby supply of limestone (necessary as flux), and trading links across the Bristol Channel to Cornwall and Devon, sources of copper ore.
As the Industrial Revolution took off, a series of works were built along the Tawe river from 1720 onwards and a series of mines were opened. Initially, the smelting works concentrated on copper. Coal was brought down to them by waggonways and tramways; copper ore was brought on ships which could sail right up to the works; and the resulting copper was exported out again. Swansea had become “Copperopolis”, and the lower Tawe valley became a mass of industry.
More and more riverside wharfs were built. Tramways, waggonways and railways proliferated and connected the different works and the collieries supplying them. Today’s Hafod was originally the village of Vivianstown (Vivian owned the Hafod Copper Works); and Morriston was founded circa 1790 (the exact date is unclear) by the Morris family who owned the Cambrian Works among other properties. “By 1750, the Swansea district was providing half the copper needs of Britain”.
The Cambrian Works closed down as a smelter but reopened as a pottery in 1764: pottery-making is another industry which requires vast quantities of coal (available locally) and clay and flint (available from the West Country, readily accessible by water). The Glamorgan Pottery was founded in 1813 by the ex-manager of the Cambrian Pottery, right next door to it and in direct competition with it. Not only the managers of the potteries but many of the workers came originally from Staffordshire. Examples of Swansea pottery can be seen today at the Glynn Vivian Art Gallery and at Swansea Museum.
Over recent years, the quality of the river has now greatly improved with salmon and trout now swimming up the river to spawn. In 1992, a barrage was built at the mouth of the river.