Alcantarilla Dam

Alcantarilla Dam
Alcantarilla Dam in 2016
Location of Alcantarilla Dam in Spain
Location	Mazarambroz (Toledo), Spain
Coordinates	39°39′36″N 4°3′28″W
Opening date	1st century
Dam and spillways
Impounds	Guajaraz (Tagus basin)
Height	20 m (66 ft)
Length	>800 m (2,600 ft)
Width (base)	4 m (13 ft)?

The Alcantarilla Dam is a Roman gravity dam built to supply water to the Roman city of Toletum –present-day Toledo, Spain–, in the Roman province of Hispania Tarraconensis. It was build in the 2nd century BC on a tributary of the River Tagus. Currently in ruins, it is located in present-day Mazarambroz (Toledo). It is believed to be the oldest dam in Spain, and is possibly the oldest known Roman dam.

The toponym "Alcantarilla" means conduit and is of Arabic origin: its Latin name is unknown. It was 20 metres (66 ft) high and at least 550 metres (1,800 ft) long. The water was conveyed to the city by an aqueduct which passed through Layos.

Structure

The structure appears to have been similar to the surviving Proserpina Dam near Merida, an earth dam with a stone retaining wall. The upstream retaining wall consists of two parallel rubble-masonry walls about 1 metre (3.3 ft) thick, separated by a concrete-filled space approximately .6 metres (2.0 ft) wide. The upstream side of the wall was faced with cut stone blocks.

Conservation

The structure has been in ruins for a long time. There has been speculation that it was not strong enough to cope with a large volume of water. It was possibly breached in the Roman era. Another possibility is that the masonry collapsed upstream, perhaps by the pressure of the earth fill when the water was low, since, unlike later dams, it was not buttressed on the upstream side.

The remains of Toledo's Roman water supply system are partly protected by a heritage designation (Bien de Interés Cultural).

See also

• List of Roman dams and reservoirs
• Roman architecture
• Roman engineering

References

• Arenillas, Miguel; Castillo, Juan C. (2003), "Dams from the Roman Era in Spain. Analysis of Design Forms (with Appendix)", 1st International Congress on Construction History [20th–24th January], Madrid, retrieved 29 December 2018 – via TRAIANVS

Further reading

• Hodge, A. Trevor (1992), Roman Aqueducts & Water Supply, London: Duckworth, pp. 87–89, ISBN 0-7156-2194-7
• Schnitter, Niklaus (1978), "Römische Talsperren", Antike Welt, 8 (2): 25–32 (29), JSTOR 44431542
• Smith, Norman (1971), A History of Dams, London: Peter Davies, p. 48, ISBN 0-432-15090-0