8/14/2019 Segovia Aqueduct

1/5

ovia txt

//www.romanaqueducts.info/aquasite/segovia/[10/11/2013 10:38:47]

For the maps and photo's, see below

Segovia from the air

Segovia (Spain)

egoviaegovia was a small Roman town on a steep isolated hill at the junction of two rivers on the main road from EmeritaMerida) to Caesaraugusta (Zaragossa). Despite its small size, the town was supplied with water by an impressivequeduct which was built sometime in the first or second century.

Segovia and its surroundings

egovia is well known for the magnificent aqueduct bridge in the centre of town, one of the largest and best preserved in the Roman empire. Theoman aqueduct channel of Segovia has a total length of 15 km from its source in the mountains to the Alcazar on the NW tip of the city, and thequeduct bridge is only a small part of this structure. Segovia is special not only because of the artistic marvel of the aqueduct bridge and medievaluildings, but also because of its setting in the wide open fields of Castille at the foot of the mountains, and the possibilities this gives to appreciatehe layout of its aqueduct.

he aqueduct obtained its water not from springs, but from a small river in the Sierra de Guadarrama. Although the Romans favoured springs forqueduct water because the risk of contamination is less, this is not everywhere possible because of the local geology. Large springs are most commonn limestone areas, and the mountains surrounding Segovia are mostly gneiss and granite. In this case, a small ledge of stone set was set oblique tohe course of the stream and this directed water into the aqueduct channel. From this source at 1255m altitude, the aqueduct channel followed theontour lines along the west side of a spur of the mountains known as the Cabeza Grande with a slope of 0,43%. The channel was mostly a buriedtructure with internal dimensions of 0,6 x 0,6 m. At the north side of the spur, the channel suddenly descended steeply by 75m over only 553 m, aope of 13,5%, to the crossing of the next major creek, the Fuentecilla de Tilviejo. From here, the aqueduct ran along the top of a long spur of hillstraight towards the city as a channel covered with granite slabs. About 1 km before the city walls, the aqueduct had to cross a 30m deep valley. This

was done by a short section of a wall and a series of arches of one and two tiers, the famous "aqueduct of Segovia". After reaching the town wall, theonduit was buried again but it seems that the aqueduct channel continued up to the Alcazar, including a cleaning basin in the Plaza Mayor. Since thelcazar is at the lowest part of the city, a distribution basin or Castellum Aqueae must have been present close to the end of the aqueduct bridge, at

he highest part of the city.

he original construction of the aqueduct seems to follow common engineering practice of early Imperial Age. A curioushenomenon is the steep section of the channel at the north side of the Cabeza Grande mountain spur. This could beue to a two phase construction of the aqueduct; possibly, a first aqueduct of only 9 km length was constructed to theeadwaters of the Fuentecilla de Tilviejo creek. When this did not produce enough water year round, a second section

was built towards the Aceveda river. It is also possible that difficulties in the terrain made it necessary to choose thisomplex trajectory.long the course of the aqueduct, several cleaning basins have been found, and many more probably existed. Theseasins are known in Spanish as a "desarenador" (de-sander). Structures of this type were common along Romanqueduct channels, especially in aqueducts like that of Segovia which carried "soft" water from a granite source that didot deposit sinter in the channel. As a result, sand was not only transported from the river source upstream, but thehannel eroded constantly by dissolution of cement that was used to bind the stones of the conduit. Several basins wereherefore needed to catch this sediment, and frequent repair jobs were needed on the actual channel to keep iteasonably waterproof.

he aqueduct of Segovia is special in that it has been used almost without interruption from Roman times to the present day. As a result, many partsf the aqueduct are still with us, and the bridge certainly survived because of its usefulness for the local water supply; it could easily have beenecycled into churches and monasteries, like in so many other Roman towns. The longevity of the aqueduct also means, however, that little of theriginal Roman aqueduct channel survived, because parts of it have been used and reused over the centuries by Romans, Visigoths, Arabs, andastillians. The most drastic measure was taken in 1929 when concrete pipes were put in place to replace the Roman channel completely. Most otheremains of the old channel must have been removed at that time.he aqueduct bridge in town and the cleaning basins underwent restoration many times, most recently in the 1970s and 1990s. A book (Gallardo975) and web sites testify to this restoration work and ongoing efforts to preserve the structure. All car traffic has now been banned from near theridge to reduce the danger of vibration and pollution. The aqueduct of Segovia is in excellent shape and maintenance, and will hopefully be andmark for many years to come.

Visible remains

ource of the aqueduct

ocation: 40.85173N, 4,06881W (WGS84)he caption of the aqueduct of Segovia lies in a small mountains stream, the Rio Aceveda, headwaters to the Rio Frio, in pine and oak forests on theorthern slopes of the Sierra de Guaderrama at 1255m altitude. The caption is one of the best preserved Roman structures of this type in existence. Itonsists of a narrow ledge or weir of gneiss blocks at a spot there the valley is slightly wider and not hammed in by steep gneiss outcrops. The weir is1 m long and consists of 26 gneiss blocks, 69cm long and of variable width, held together with (modern) iron clamps in lead, which mimic theriginal Roman setting and use the small holes in the stones.

http://www.romanaqueducts.info/aquasite/foto/segoviagooglemap.jpg

8/14/2019 Segovia Aqueduct

2/5

ovia txt

//www.romanaqueducts.info/aquasite/segovia/[10/11/2013 10:38:47]

The source

Casa Aqua

The weir lies at approximately 45 to the axis of the river and channels the water to the north side of the stream,where it is led into the actual aqueduct channel with a maximum debit of 50 litres per second. The head of the aqueductis made of large nicely worked granite blocks. A modern steel sluice gate can close off the channel, but a ledge in thestone suggests that the Roman caption used a sluice gate as well, possibly of wood.This kind of weir is known in Spanish as an "azud", and the channel leading away from such a dam a "caz". Like mostwords to do with water in Spanish, these are derived from Arabic.

Valdeconejos bridge

Not far from the source, the aqueduct channel had to cross the small brook of Valdeconejos (valley of rabbits). Here isn interesting structure in the form of a small bridge of 5 granite plates that still serve their original purpose of leading the water of the small creek ofaldeconejos over the top of the aqueduct channel. In most Roman aqueducts, the channel is lead on a bridge over small drainages, but here the

pposite solution was chosen.

ow to reach these sections

oth the Azud (the source) and the Valdeconejos bridge can be reached on foot in about 1 hour (3km) from the village of Revenga. Park in Revengar at the entrance of the road that runs along the north side of the Embalse the Puenta Alta Lake. Follow the road to the parking beyond the end ofhe lake and then follow the yellow aqueduct signs up the hill. From the parking, take the track that goes up steeply and passes through the fence,ollow this to above the creek on the north side until the track reaches some meadows; cross the creek here, and follow the yellow signs steeply uphe hill till reaching the aqueduct channel at 40,85727N, 4,07430W; this can be recognised by the box-shaped maintenance shafts that have beennstalled on the water pipe in the early 20th century. Follow the track now along the contour lines towards the captions upstream (to the right, sign toazud"). On the way back, the aqueduct can be followed past Valdeconejos until reaching the track that descends again to Revenga. It is evenossible to follow the aqueduct all the way to the city. The tourist information in Segovia can organise trips to the aqueduct source, and has arochure (in Spanish) describing three walks along the course of the conduit, from the mountains to the city.

Remains of the channel

long the track that follows the hilltop between Segovia and the mountains, several fragments of the Roman channel can be seen. This includes partsf the actual channel, and some granite cover stones.

o see these remains, either take the small asphalt road that leads east from the Revenga-Segovia road up to a farm on the north side of the road,nd walk from here north or south. Alternative is to walk south from the city or from the Segovia - San Ildefonso road towards the track of thehannel. The new high speed train between Segovia and Madrid unfortunately cuts the track of the aqueduct, but it can be avoided on the east side.he approximate trace of the aqueduct can be seen on air photos because it is followed by an artificial open channel that provides water to theurrounding vegetation. At some time during the history of the aqueduct, it apparently functioned as a open channel. Nearby can be seen remains ofeveral stages of the aqueducts operation in a 100m wide zone, including the pipeline from the 1920s.

asa de Piedra or "el Casern"

long the west side of Avenida Juan de Bourbon y Batenberg, before reaching the Plaza de Toros, lays the first cleaning basin of the aqueduct. This

asin is in a small concrete building, known locally as the Casa de Piedra or el Casern. It has is 5,50 x 5,90 m with a door on the north side and awindow in the opposite wall. The aqueduct entered from the south and left at the north side and passed through a basin of 2,25 x 3,10 m and 2meep. The basin could be cleaned by means of a side channel to the west of the same depth as the basin, which could be opened with a sluice toush out the basin. The channel that leaves the building on the north side is not the original Roman aqueduct channel but a later replacement with aiameter of 0,30 x 0,30 m. The building itself is at least partly Roman.

queduct wall

t the junction of the Calle del Coronel Rexach and the Avenida del Padre Claret is a small monument that marks the start of the most spectacularection of the Segovia aqueduct. The cylindrical stone is a monument from the 17th century, found close to Segovia. It has been placed on the wallhat originally supported the Roman aqueduct channel, and which now carries its narrower successor, a 30 x 30cm channel from the 15th century.his wall, 141 m long and 1,4 m wide, runs up to a building that covers the second and final cleaning basin before the aqueduct bridge.

Casa de Aqua

This building, 8,90 x 7,50 m is known locally as the Casa de Aqua. Inside is a basin of 4,25 x 2,18 m, 2,90 m deep withan entry and exit of the aqueduct channel. Contrary to the Casa de Piedra, there is no channel at the base of the basin,so that any sediment that accumulated had to be removed by hand, and could not be flushed out. There is a diversionchannel on the west side of the building, but it probably only served to skim off floating debris like leaves and branchesbefore the water entered the aqueduct bridge where any dirt would be extremely difficult to remove. The building is atleast partly Roman.

queduct bridge

he aqueduct bridge of Segovia starts at the Casa del Aqua. A 42 m long section of wall is followed by a 683 m long bridge of arches in a section thathanges direction several times. The corners where the bridge changes direction have not been strengthened in any way. A first section of 75 singerches is followed by the most famous section of two tiers and 44 double arches that crosses the valley close to the city wall with a maximumevation of 29 metres. The aqueduct bridge is completely built in opus quadratum, large blocks of granite without the use of cement. This method ofonstruction is probably imposed by the lack of limestone to make cement in this part of castille, but helped to preserve the building by making theridge flexible to survive small earthquakes, settling and small motions due to wind and temperature gradients. The ornamentation of the bridge isparse and restricted to imposts along the tops of the spandrels, at the springing of the arches, and in the piers. The imposts were probably meant asrnamentation, but also to carry the formwork to build and maintain the bridge. The diameter of the piers decreases stepwise by one Roman footpwards at the imports from 3 x 2,4 m at the base of some pillars to 2,5 x 1,8 m at the top. Because of the decreasing diameter of the piers, therches increase in span from 4,5 m to 5,1 m at the top.he aqueduct is special in that nearly every pillar and spandrel has a different design. Some arches have a commonpringer, others have spearte but touching ones, and the base of many of the spandrels is different. This may partly beue to later reconstruction, but especially in the two tier section of the bridge, the design seems to be original. This

would imply that the bridge was not designed in advance in great detail, but that arches and spandrels were designed

http://www.romanaqueducts.info/aquasite/foto/casaaqua0.jpghttp://www.romanaqueducts.info/aquasite/foto/weirsegovia.jpg

8/14/2019 Segovia Aqueduct

3/5

ovia txt

//www.romanaqueducts.info/aquasite/segovia/[10/11/2013 10:38:47]

The aqueduct bridge

n the spot with the bocks that happened to be available and designed as construction progressed.

egovia is mostly underlain by soft sandstone, but the hill to the east where the bridge starts consists of gneiss. Thequeduct pillars are either set directly on the gneiss, or in foundation pits that have been excavated in the softandstone, mainly in the double arched part of the bridge. The Roman engineers apparently realised the differentroperties of the two rock types, and decided to take no risk with the sandstone. A gneiss outcrop supporting a pillar cane seen in one of the last pillars of the single arch section, before the final bend that leads to the city (pillar 71)

he bridge is built from approximately 20.400 blocks of granite, 7.500 m3 of granite with a total weight of 20.000 tons. The largest block in the bridgeas a weight of 2 tons, and blocks of 1.000 kg are common. The granite was obtained locally from granite outcrops NE of the city up to 5 km away.

ince no quarries have been found that can have produced such a large amount of granite, it is assumed that the blocks were obtained from largeranite boulders that dotted the landscape at that time; presently, there is a marked absence of large granite boulders close to Segovia.mall holes in most of the granite blocks of the bridge indicate that the bridge was built using cranes with grips that tightens when weight isuspended.he rounded, bossed form of the granite blocks of the aqueduct is partly original, but also enhanced by weathering of the relatively soft granite in theourse of time.

he deck of the bridge carries the specus of the aqueduct, but this is actually a pile of concrete which has gradually been added to over the course ofhe life of the bridge; the Roman section is probably buried somewhere in the lower part. Most of the specus and the channel presently visible at theop of the aqueduct date from the 15th century. This channel, 30 cm wide, is much smaller than the Roman specus which was 0,6 x 0,6 m. Theresent slope of the channel along the top is variable, but is mostly below 1%.

he small section of wall of 16 x 2m in the second tier of the aqueduct over the centre of the bridge was initially meant to carry an inscription andtatues, possibly of Hercules, the legendary founder of Segovia. The bronze letters have long since been removed, and the only thing left are the holeshat were used to attach the letters to the wall. Several suggestions have been made for a reconstruction of the inscription, based on the shape andetting of these holes, but no agreement exists to date. The aqueduct has therefore been attributed to Claudius, Trajan or Nerva, depending on theeconstruction. The two most quoted reconstructions are:

IMP NERVAE TRAIANVS CAES AVG GERM P M TR P II CO S II PATRIS PATRIAE IVSSVP. MVMMIVS MVMMIANVS ET P. FABIVS TAVRVS IIVIRI MVNIC FL SEGOVIESIVM

AQVAM RESTITVERVNT

r an older one:TI ClAVDIVS PONT MAX VIII COS III TRIBVNICIA POTESTATE VIIII IMP PP OMNIVM FECIT

arts of the aqueduct bridge have been torn down or collapsed during its long history, especially in the lower, upstream part. Every time thisappened, it has been fatefully reconstructed, although not always with the original stone and design. As a result, several of the first upstream archesave a distinctly un-Roman pointed profile to them.

he section in the city

t the top of the bridge, just inside the city wall, are four arches preserved of an original arrangement of 9: these arches carried the aqueduct up to a

ection of wall with a sharp curve to the west, towards the centre of the city and the Alcazar. No Castellum Aquae has been found to day, but thismay have been present somewhere in the first section after the bridge. Recently, a cleaning basin and section of the aqueduct was found below the

aza Mayor.

ees Passchier

egovia - SEGOVIA

Item Info

Length 14,965 km

Cross-section 0,6 m x 0,6 m

Volume 1800 - 4500 m3/day

Fall 1,6 %

Period Augustan

Features

river intakeaqueduct bridge

Recommended literature : Supervivencia de una obra hidrulica: el acueducto de Segovia, by Aurelio Ramrez Gallardo (1975)Tras la huella del aqueducto., by Charo Domnguez and Cristina Pampilln (2007). Ayuntamiento de Segovia

Recommended website :F. Jurado: E l Acueducto Romano de Segovia (2002) ,in SpanishNN: Segovia, su acueducto y ...., in Spanish

How to visit : see above

HOME More literature on more aqueducts Last modified: November, 2007 - (webmaster)

http://traianus.rediris.es/textos/segovia.htmhttp://traianus.rediris.es/textos/segovia.htmhttp://www.tarraconensis.com/segovia/segoviacueducto.htmlhttp://www.romanaqueducts.info/index.htmlhttp://www.romanaqueducts.info/aqualib/aqualit.htmmailto:wilke@romanaquaducts.infomailto:wilke@romanaquaducts.infohttp://www.romanaqueducts.info/aqualib/aqualit.htmhttp://www.romanaqueducts.info/index.htmlhttp://www.tarraconensis.com/segovia/segoviacueducto.htmlhttp://traianus.rediris.es/textos/segovia.htmhttp://www.romanaqueducts.info/aquasite/foto/bridge2segovia.jpg

8/14/2019 Segovia Aqueduct

4/5

ovia txt

//www.romanaqueducts.info/aquasite/segovia/[10/11/2013 10:38:47]

Sketch map

Weir in Aceveda River

Weir at the source

Detail of the weir

Sluice gate

Bridge of Valdeconejos

Coverstones

View from the north

View from the west

Interior of the Casa

Southern side of the Casa

Channel below the doorway

Bulb as a filter

Inside the Casa de Aqua

Looking downstream

Single arches

Reused stone

Overflow

Base of a bridge pier

Start two-tier section

http://www.romanaqueducts.info/aquasite/segovia/foto1.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto2.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto3.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto4.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto5.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto6.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto7.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto8.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto9.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto10.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto11.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto12.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto13.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto14.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto15.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto16.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto17.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto18.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto19.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto20.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto20.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto20.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto19.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto19.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto18.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto18.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto17.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto17.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto16.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto16.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto15.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto15.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto14.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto14.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto13.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto13.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto12.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto12.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto11.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto11.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto10.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto10.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto9.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto9.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto8.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto8.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto7.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto7.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto6.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto6.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto5.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto5.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto4.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto4.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto3.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto3.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto2.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto2.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto1.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto1.html

8/14/2019 Segovia Aqueduct

5/5

ovia txt

Detail of a pier

Central part

Evening view

Aerial view

Bridge with niche

Bronze letters have been removed

The 15th century channel

pier 117

Final section of arches

Early morning view

GoogleEarth View of Segovia

Typical hoisting grip

http://www.romanaqueducts.info/aquasite/segovia/foto21.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto22.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto23.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto24.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto25.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto26.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto27.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto28.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto29.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto30.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto31.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto32.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto32.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto32.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto31.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto31.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto30.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto30.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto29.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto29.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto28.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto28.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto27.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto27.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto26.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto26.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto25.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto25.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto24.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto24.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto23.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto23.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto22.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto22.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto21.htmlhttp://www.romanaqueducts.info/aquasite/segovia/foto21.html