Townshend's Great Leat & Waggonway

Cadw's description

Summary description and reason for designation

The following provides a general description of the Scheduled Ancient Monument.

The monument comprises an extensive system of leats which was constructed by Chauncy Townshend around 1750 to provide water power for his coal and copper smelting works in the Swansea Valley. This area contains well preserved remains of three leats, as well as a section of his waggonway, all in close proximity to the Gwernllwynchwyth Colliery. Townshend's Great Leat, built c. 1757, ran for four miles from the Glais Brook to Pentre-chwyth. This was of exceptional importance in the early industrial development of the area. Surviving water power systems of this period for early heavy industry are now rare, and these sections form important examples of their design and construction. Townshend's Waggonway was a wooden horse-drawn railway, and the earliest major innovation in industrial transport in the valley.

The monument is of national importance for its potential to enhance our knowledge of 18th or 19th century inductrial practices. It retains significant archaeological potential, with a strong probability of the presence of associated archaeological features and deposits. The structure itself may be expected to contain archaeological information concerning chronology and building techniques. A leat may be part of a larger cluster of monuments and their importance can further enhanced by their group value.

The scheduled area comprises the remains described and areas around them within which related evidence may be expected to survive.