Ancient Monuments

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Sarn Howell Pond and Watercourses

A Scheduled Monument in Town (Y Dref), Merthyr Tydfil (Merthyr Tudful)

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Latitude: 51.7448 / 51°44'41"N

Longitude: -3.3394 / 3°20'21"W

OS Eastings: 307620

OS Northings: 205969

OS Grid: SO076059

Mapcode National: GBR HQ.18QD

Mapcode Global: VH6CZ.2DFS

Entry Name: Sarn Howell Pond and Watercourses

Scheduled Date: 21 July 1997

Source: Cadw

Source ID: 1452

Cadw Legacy ID: GM494

Schedule Class: Water Supply and Drainage

Category: Pond

Period: Post Medieval/Modern

County: Merthyr Tydfil (Merthyr Tudful)

Community: Town (Y Dref)

Traditional County: Glamorgan


The monument consists of a collection of water management features connected with the supply of Dowlais Ironworks and its associated iron and coal mines. The Dowlais works grew rapidly in the early 19th century to become the largest in the world, leading to much greater demands for water to supply waterwheels, balances and steam engines at the works and its surrounding mines. Water resources were collected by an exceptionally intensive network of reservoirs and leats constructed on the surrounding watersheds. By 1862 the system included 37 named reservoirs totalling 83 acres, and tens of miles of leats. Water was also transferred and stored underground. The Sarn Howell watercourse was one of the principal leats, bringing water across the Cwm Bargoed watercourse and storing it in Sarn Howell Pond. This part of the system probably dates from about 1818, and was well developed by 1839. Remains include a series of leats and holding ponds for the Sarn Howell watercourse, and sidings from the incline railway from Penydarren Pits. South of this are the ruins of the incline winding engine house, and the Sarn Howell pond, with parallel dams either side of a saddle in the hill and a leat running away from it on the west side. A separate area to the east contains another well-preserved section of the main watercourse, smaller leats, and a square stone-lined tank.

The monument is of national importance for its potential to enhance our knowledge of maritime practices. It retains significant archaeological potential, with a strong probability of the presence of associated archaeological features and deposits.

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

Source: Cadw

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