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Underground medieval water distribution network in a Spanish town
Tunnelling and Underground Space Technology 51 (2016) 90–97
Contents lists available at ScienceDirect
Tunnelling and Underground Space Technology journal homepage: www.elsevier.com/locate/tust
Underground medieval water distribution network in a Spanish town Andrés Carrión a,b,⇑, Antonio Fornes b,1 a b
Universitat Politécnica de Valencia, Camino de Vera s/n, 46020 Valencia, Spain Speleological Society La Senyera, c/ Monte Carmelo, 4, 46019 Valencia, Spain
a r t i c l e
i n f o
Article history: Received 23 January 2015 Received in revised form 20 August 2015 Accepted 8 October 2015
Keywords: Water distribution Underground cistern Medieval tunnel
a b s t r a c t The city of Alcudia de Crespins, in the centre of the Valencia province (east of Spain), has an exceptional water distribution system that in the past served fresh water to many houses in the town. This system is formed by more than one km of tunnels and underground cisterns, and dates probably in the late medieval times, while it has been in use and suffering modifications until 1955. This paper presents the structure and characteristics of such exceptional system, and explains the functioning parameters of the infrastructure. Ó 2015 Elsevier Ltd. All rights reserved.
1. Introduction The east of Spain is a Mediterranean climate region, with dry summers and winters and two rain seasons in spring and autumn, with a total rain amount of about 600 mm per year in the area of the city here studied. Thus, water has been always a priority in all human populations in the region, and the knowhow of water distribution, control and use has reached traditionally a remarkable level. Underground cisterns for rain water are frequent in the region, named after an Arab term as ‘‘aljibes” or ‘‘aljubs”, while there are present before the Arab period, as some of them are dated in the 4th century BC, or even before (Egea Vivancos, 2010; Llanos Ortíz de Landaluze, 2010). In the Roman times (for this region approx. 150 BC to 450 AD), important water infrastructures were constructed, and relevant aqueducts can be found in Tarragona, Chelva, Albarracín and other places, frequently including not only the best known scenic image of arches crossing a valley, but also tunnels of hundreds of meters long. In the Arab period (from 700 AD to 1250 AD) the use of water for agriculture reached high level not only in infrastructures (probably based on Roman schemes) but also in water management, as is proved by the existence of the ‘‘Water Court of the Plain of Valencia”, better known by its shortened name of ‘‘Water Court”, the oldest existing justice institution in Europe, dating from the ⇑ Corresponding author at: Universitat Politécnica de Valencia, Camino de Vera s/n, 46020 Valencia, Spain. E-mail address: [email protected] (A. Carrión). 1 A. Fornes sadly passed away on February 2015, while working on this research. We all regret his loss. He will be deeply missed. http://dx.doi.org/10.1016/j.tust.2015.10.015 0886-7798/Ó 2015 Elsevier Ltd. All rights reserved.
10th/11th century, and still active (Prytherch, 2009). The starting of water mining activities is probably related also with the Arab period, as they imported to the dry regions of Spain the construction of ‘‘qanats” or water mines, long underground galleries to capture water springs (Juncà Ubierna, 1998; Stiros, 2006; English, 1998). With this background, the idea of underground water storage and conduction has been easily incorporated into daily life, and where geological characteristics and water availability allow, we can find interesting examples of water infrastructures. In this paper we present one of such cases. Before starting with the study of our specific case, it can be convenient to put in context the water underground infrastructures. We will refer to qanats and aqueducts, as examples more related with our case. Qanats are structures characterized by a double function of conveying water from underground springs or aquifers, and transport water to an area requiring its use, for irrigation or for human use. Qanats, with different names (Foggara in the North Africa, Karez in Afghanistan, and up to 27 different names in countries from Japan to Spain, including Iran and the Middle East, Hamidian et al., 2015) have played a relevant role in water capturing and transporting in dry climate areas, and in different parts of Spain, including the region of Valencia, there are some examples of these structures (Iranzo and Hermosilla, 2011; De Bustamante et al., 2015). While in Iran qanats achieve extraordinary sizes (up to 80 km, Hamidian et al., 2015) in the east of Spain lengths are not so important, and Iranzo and Hermosilla (2011) for an area 40 km east of Alcudia (our area of study) identify eight qanats with lengths under 500 m.
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Fig. 1. General plan of the network with indication of the cisterns.
The other infrastructures we will briefly comment are aqueducts, specifically the tunnels related to them. To some point a qanat is also an aqueduct, or at least one of his sections plays this role. The world of aqueducts is extremely complex and is out of the focus of this paper, but at least we have to mention that in the Mediterranean countries they have played a very significant role for supplying water to cities and irrigation systems. In the east of
Europe, we find well studied examples like the Eupalinos tunnel, in Samos (Greece) to cite only one (Stiros, 2009). In France there are magnificent examples, as the Lyon Roman aqueducts, where more than 3.8 km of tunnels have been constructed (Burdy, 2002). In Spain, as in the entire in Roman world, we find various examples of aqueducts requiring tunnels. We will mention only two examples. In Chelva, 60 km north of Alcudia, we can find the
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Peña Cortada, a nice example of an aqueduct using tunnels. In Albarracín, 150 km NW from our area of study, a Roman aqueduct includes a main tunnel of almost 5 km length (Arenillas, 2007). 2. The city of Alcudia de Crespins The small city of Alcudia de Crespins, in the center of the Valencia province, with 5000 inhabitants, lies in the Cañoles River Valley, at an altitude of 150 m over the sea level. Near to the city, the spring of ‘‘Los Santos” supplies water to the villages of the area. Materials in the underground of Alcudia de Crespins are formed by horizontal layers of different materials, from lake limestone to clay, including carbonated marls (the more frequent material) and also sporadic layers of sand, slime and even thin gravel and pebbles layers. The result is a homogeneous material, with dominant whitish tones due to calcium carbonate limestone and lake marls. These materials were deposited in a lake area formed by an important travertine structure, probably dated in the Medium Pleistocene, as it is superimposed (but included in the same alluvial sequence) to a river terrace of that age (IGME, 1976; Garay, 2015). This material is consistent enough to allow digging, but at the same time relatively easy to dig.
3. The underground water supply system In a moment that cannot be precisely determined, as ancient documents don’t cite this fact, a branch of the channel that brings water from Los Santos river, was constructed. This river is born in Los Santos spring, one and half km east of the network entrance point. The branch consists in a tunnel of about 130 m long, ending in an underground cistern (cistern 1.1 in Fig. 1). The cistern was under the Lord’s Palace that existed in the city since the 14th century. Today the Palace has disappeared, and the central place of the village occupies its location, but the channel and the cistern are still there, five meters under the surface. After this initial channel, the network of water supply tunnels started to grow. Only three meters before cistern C 1.1, in the left side of the tunnel a new gallery starts forming a 90° angle and drawing a curve around the cistern (proving that cistern 1.1 exists when this tunnel was excavated). From here, different branches of the network were excavated to serve water to other neighbors’ houses and to a well of public use (cistern 1.2). Under each house, a cistern was excavated. The public well consists in a cistern with eight shaped well, forming almost a double well, maybe to host some type of water wheel. Fig. 1 shows
Fig. 2. Network plan superimposed with the city view.
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As a result, better than a net, the general shape is like a tree. Only in one point we find a loop in tunnels, closed by rubble work, and this is not linked with the water circulation. 4. The galleries
Fig. 3. One of the authors (A. Fornes) surveying in a galleries junction.
the plan of the network, and Fig. 2 put this plan in relation to the city aerial view. The general structure of the network follows the following criteria: Water enters by the oldest part of the network and traverses under the city up to an open air channel on the other side of the town. From a main tunnel, lateral tunnels fed the houses’ cisterns.
The galleries were excavated using traditional methods, inherited from Roman and Arab times. These methods try to minimize excavation effort and time using multiple working faces. To do this, and using Roman terminology according to Vitruvio (VIII, 7) (Vitruvio, 2012), tunnels have regularly spaced shafts, named putei or spiramina that had a triple purpose: they allow excavating simultaneously from these shafts; they also had a ventilation function; and they served for material extraction purposes during the excavation process. These putei should be separated by one or two actus (one actus = 37.5 m). Qanat construction procedures are also similar, and shafts with the same functions can be found, having a spacing of 50–100 m (Stiros, 2006; English, 1998). The basics of this working procedure are to some point similar to today’s working schemes, with obvious technological differences. In our network these putei can be found in different places of the network, and they are not so frequent as should be according to Vitruvio’s recommendations due to the fact that cisterns also serve for this purpose. In any case, at least six of these wells can be found, marked with P in Fig. 1. If we take into account that cisterns’ wells may have the functions of putei, with a total of fifteen cisterns plus six putei, the mean distance between wells is 48 m, in the range of the above mentioned schemes (in Roman aqueducts distance is between 37.5 and 75 m, in traditional qanats is between 50 and 100 m). Tunnels walls show excavation tool marks, with a typical arch shape as effect of the excavation movement. Tool marks are about 3–5 cm wide, corresponding to a flat tool. No remains of tools have been found in the tunnels. There are also, in the walls, frequent small cavities used as light points. While the main tunnel section varies frequently, typical section is 0.60 m wide and 1.80 m high. Lateral galleries, driving to individual cisterns have frequently smaller width and/or high. The gradient of the network galleries is about 1.5/2 per thousand. The deep
Fig. 4. Two images of the galleries: Left, the main gallery, with a blocked entrance to a secondary gallery. Right, a lateral smaller gallery.
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of circulating water was about 30 cm, as can be noted from the waterproofing cover of tunnel walls. This cover is similar to Roman opus signinum (this material was a plaster or cement used for making pavements and for waterproofing aqueducts, and was made with ceramic tiles or pottery broken in small pieces, almost a powder, mixed with mortar and beaten down with a rammer (Matias et al., 2014)). In some places deep is greater, especially in the gallery cistern, where water seems to fill almost completely the tunnel, creating a reservoir, before reaching a level that permit the water to continue to other parts of the network. Total length of the network is 1010 m, corresponding to the galleries that can be visited. Twenty-eight galleries are closed by masonry, rubblework or rubble, meaning that the true length of the network is with certitude greater.
One of these closed galleries was also the exit of the network to the open air, essential in the operation procedure of the system. Figs. 3 and 4 show different views of the galleries.
5. The cisterns A total of fifteen cisterns were located and studied. Its approximate capacity ranks from 3.6 m3 (in cistern 4B.2, Fig. 1) to 67 m3 of the Palace cistern (C 1.1. in Fig. 1) and 75 m3 in the Gallery Cistern (C.5.1., Fig. 1). The total capacity registered in these 15 cisterns is 269 m3. Almost half of this capacity corresponds to only two of the cisterns (Palace cistern and Gallery Cistern). The third cistern in capacity corresponds to the old public well of the city, with 30 m3.
Fig. 5. Two images from the cisterns: Left, the double well in cistern 1.2. Right, an image of cistern 5.2.
Fig. 6. Cistern types in Alcudia.
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If we eliminate these three special cases, the rest of the cisterns correspond to domestic reservoirs for private use. For these cisterns, capacities ranks from 3.6 to 17 m3, with a mean of 8 m3. The general structure of cisterns corresponds to sub-circular plan of 2.5 m diameter, a deep of 1.5 m and a well to extract water almost in the center of the ceiling. Some exceptions can be made to this general shape: Cistern 1.1, or Palace cistern. It has a rectangular plant with one end rounded. Its dimensions of 8 3 m plant and 4 m deep denote its special use, as a palace in medieval times was more than a simple house. Cistern 1.2, corresponding to the city public well. Its plant is rounded, and of greater dimensions than regular (domestic) cisterns, but its main characteristic is its double well: the shaft formerly leading to the surface has an 8 shaped horizontal section (see Fig. 5 left and plan in Figs. 6 and 7). This structure is similar to those wells with a type of chain water wheel called ‘‘noria de cangilones”, in which the double well serves one for the descent of the water recipients and the other for the ascent (see Figs. 7 and 9). Fig. 8 shows a photo a water wheel of this type, still with the main wheel in position but nowadays out of use. Cistern 4.1. It has a triangular plant, completely out of the standard. The reason for this shape in unknown. Cistern 5.1, or Gallery Cistern. Two are the specificities of this cistern. The first one is that the same gallery of the tunnel has reservoir functions, serving both to feed the downstream parts of the network and as reservoir, accessible as cistern by the extraction well at the end of the gallery. The second one is that is the only part of the galleries that is below the general level of the water flow. The walls of the galleries are waterproofed usually about 30–50 cm high, but in the gallery cistern waterproofing is up to the ceiling. It is difficult to understand the role of this cistern in the network, and it has to be considered that it
Fig. 8. Water wheel of Bolnuevo (Murcia, Spain). (Image taken from http://www. regmurcia.com/servlet/s.Sl?sit=c,522,m,205&r=CeAP-10306-R_933_DETALLE_ REPORTAJES.)
seems to be relatively modern. Graffiti at the entrance of this section warns about the fact that the gallery can be completely inundated. Fig. 6 shows different cisterns: a typical domestic cistern (4.2), plus two of the non-standard ones (1.1 and 1.2). Fig. 7 shows the hypothetical reconstruction of the chain water wheel in the cistern of the public well (cistern 1.2), according to the testimonies of people from the city. A ceramic piece found in the cistern may be part of one of the recipients. In Fig. 8 we have a view of the water wheel of Bolnuevo (Murcia, Spain), from inside the shaft to the wheel. Similarly to cistern 1.2, an eight shape can be recognized in the section of the well. Fig. 9 is a drawing from the XVIIth century showing this type of water wheel (Lastanosa, 1601).
Fig. 7. Hypothetical reconstruction of the chain water wheel in cistern 1.2.
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entrance to the tunnels, with a gate located at the entrance to the network (see Fig. 1), and up today the access to the network. The gate was closed when the water exits by the other end of the tunnels, located about 300 m south of the entrance, and today disappeared, and from there used for irrigation. It was assumed that when the water exits, cisterns have been filled. Each house was responsible for the maintenance of its own cistern, and the Irrigation Association was responsible for the maintenance and cleaning of the tunnels.
7. Conclusions and final comments
Fig. 9. Chain water wheel in a XVII century drawing (Lastanosa, 1601).
While today only fifteen cisterns are accessible, the network includes other cisterns. At least 28 galleries are closed and eventually each one communicates with a cistern, or maybe more. We find the following cases: Some of the closed galleries are partially isolated from the main galleries, closing the passage with masonry, but leaving an entrance for the water that feeds the cistern. This entrance usually consists of a ceramic tube, and corresponds to ancient structures, compatible with the use of the tunnel network as water supply system. In some cases closures completely block the passage, and indicate the end of the function of the corresponding part of the network. Some are clearly related to changes in the streets of the city, as is the case of closures marked with B in Fig. 1, related to the construction of a new avenue: Closures are aligned and made with the same type of masonry. By the topography of surface and the houses distribution over this area of the network, probably only one cistern can be fed by each of this three galleries. In other cases the property of the house over the cistern closes the access tunnel when cistern became out of use, instead of simply closing the well as was the case in the accessible cisterns. Considering these non accessible cisterns, a conservative estimation of the total capacity of cisterns in the network increases this from 269 m3 (only accessible cisterns) to about 500 m3, considering that all these hidden cisterns are of domestic size. 6. Network operation Even considering that the network was abandoned in 1955, almost 60 years ago, we had the opportunity of interviewing the last person responsible for its operation. The channel feeding the network has the name of ‘‘setenes”, and is still in operation. This name indicates that this main channel distributes water for seven minor irrigation ditches, feeding each one day of the week. This secondary irrigation ditches were named upon the day of the week they are in operation, and these names have been applied also to the areas irrigated by each one. Testimonies explain that this domestic water supply network was fed every Wednesday. The procedure consists in opening the
To our knowledge, this supply system extended to a relevant number of houses in a village is unique. The system has provided fresh water to the citizens during centuries, and became obsolete when a modern drinking water distribution system was established. Its memory has been at risk of disappearing, and young generations didn’t know about it until these recent researches. Underground civil infrastructures are frequently underestimated, but they are a relevant part of the history of how humans have faced challenges of daily life. Its preservation starts with the public knowledge, and needs the support of public authorities. Avoiding damages to this (and other) infrastructure is a common responsibility of the community, starting by civil engineers and contractors who need the support of other specialists, as archeologist and historians. Acknowledgements The support of the Major of the city, Mr. Javier Sicluna, has been essential to these researches, as well as the information and help provided by Mr. Antonio Beltran, former member of the City Council, and other citizens of Alcudia de Crespins. To all of them and to the members of the Speleological Society La Senyera our sincere gratitude. References Arenillas, M., 2007. A brief history of water projects in Aragon. Int. J. Water Resour. Dev. 23 (1). Burdy, J., 2002. Les aqueducs romains de Lyon. Presses Universitaires de Lyon, France. De Bustamante, I., Sanz, J., Iglesia, J., Lopez-Camacho, B., 2015. Some Examples of Spanish Qanats. (accessed June 2015). Egea Vivancos, A., 2010. La cultura del agua en época Ibérica: Una visión de conjunto (Water in the Iberian period: the big picture). Lvcentvm XXIX, 119– 138. English, P., 1998. Qanats and life worlds on Iranian plateau villages. In: Albert, J., Bernhardsson, M., Kenna, R. (Eds.), Transformation of Middle Eastern Natural Environment, Bulletin Series 103, Yale School of Forestry and Environmental Studies. Yale University Press, pp. 187–205. Garay, P., 2015. Notas Geológicas. Lapiaz, Monographic 8, L’Alcudia de Crespins Subterránea. Hamidian, A., Ghorbani, M., Abdolshahnejad, M., Abdolshahnejad, A., 2015. Qanat, traditional eco-technology for irrigation and water management. Agric. Agric. Sci. Proc. 4, 119–125. IGME, 1976. Mapa Geológico de España, Canals. IGME, Madrid. Iranzo, E., Hermosilla, J., 2011. Las galerías drenantes o foggaras de la Safor. Documents of the Hidrographic Confederation of River Jucar. (accessed April 2011). Juncà Ubierna, José A., 1998. Tunnel heritage in Spain: roots of the underground. Tunn. Undergr. Space Technol. 13 (2), 131–141. Lastanosa, P.J. de, 1601. Los veintiún libros de los ingenios y de máquinas. Manuscript of the XVII century. National Spanish Library. . Llanos Ortíz de Landaluze, A., 2010. El estanque celtibérico de la Barbacana (Laguardia, Alava) dentro del conjunto de estanques de la península. Cuad. Arqueol. Univ. Navar. 18, 263–282. Matias, G., Faria, P., Torres, I., 2014. Lime mortars with heat treated clays and ceramic waste: a review. Constr. Build. Mater. 73 (30), 125–136.
A. Carrión, A. Fornes / Tunnelling and Underground Space Technology 51 (2016) 90–97 Prytherch, David L., 2009. Elegy to an iconographic place: reconstructing the regionalism/landscape dialectic in L’Horta de València. Cult. Geogr. 16 (1), 55– 85. Stiros, S.C., 2006. Accurate measurements with primitive instruments: the ‘‘paradox” in the qanat design. J. Archaeol. Sci. 33, 1058–1064.
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Stiros, S., 2009. Orientation and alignment of the 5TH C BC tunnel of Eupalinos at Samos (Greece). Surv. Rev. 41 (313), 218–225. Vitruvio, M., 2012. The Ten Books on Architecture. Courier Dover Publications.
Contents lists available at ScienceDirect
Tunnelling and Underground Space Technology journal homepage: www.elsevier.com/locate/tust
Underground medieval water distribution network in a Spanish town Andrés Carrión a,b,⇑, Antonio Fornes b,1 a b
Universitat Politécnica de Valencia, Camino de Vera s/n, 46020 Valencia, Spain Speleological Society La Senyera, c/ Monte Carmelo, 4, 46019 Valencia, Spain
a r t i c l e
i n f o
Article history: Received 23 January 2015 Received in revised form 20 August 2015 Accepted 8 October 2015
Keywords: Water distribution Underground cistern Medieval tunnel
a b s t r a c t The city of Alcudia de Crespins, in the centre of the Valencia province (east of Spain), has an exceptional water distribution system that in the past served fresh water to many houses in the town. This system is formed by more than one km of tunnels and underground cisterns, and dates probably in the late medieval times, while it has been in use and suffering modifications until 1955. This paper presents the structure and characteristics of such exceptional system, and explains the functioning parameters of the infrastructure. Ó 2015 Elsevier Ltd. All rights reserved.
1. Introduction The east of Spain is a Mediterranean climate region, with dry summers and winters and two rain seasons in spring and autumn, with a total rain amount of about 600 mm per year in the area of the city here studied. Thus, water has been always a priority in all human populations in the region, and the knowhow of water distribution, control and use has reached traditionally a remarkable level. Underground cisterns for rain water are frequent in the region, named after an Arab term as ‘‘aljibes” or ‘‘aljubs”, while there are present before the Arab period, as some of them are dated in the 4th century BC, or even before (Egea Vivancos, 2010; Llanos Ortíz de Landaluze, 2010). In the Roman times (for this region approx. 150 BC to 450 AD), important water infrastructures were constructed, and relevant aqueducts can be found in Tarragona, Chelva, Albarracín and other places, frequently including not only the best known scenic image of arches crossing a valley, but also tunnels of hundreds of meters long. In the Arab period (from 700 AD to 1250 AD) the use of water for agriculture reached high level not only in infrastructures (probably based on Roman schemes) but also in water management, as is proved by the existence of the ‘‘Water Court of the Plain of Valencia”, better known by its shortened name of ‘‘Water Court”, the oldest existing justice institution in Europe, dating from the ⇑ Corresponding author at: Universitat Politécnica de Valencia, Camino de Vera s/n, 46020 Valencia, Spain. E-mail address: [email protected] (A. Carrión). 1 A. Fornes sadly passed away on February 2015, while working on this research. We all regret his loss. He will be deeply missed. http://dx.doi.org/10.1016/j.tust.2015.10.015 0886-7798/Ó 2015 Elsevier Ltd. All rights reserved.
10th/11th century, and still active (Prytherch, 2009). The starting of water mining activities is probably related also with the Arab period, as they imported to the dry regions of Spain the construction of ‘‘qanats” or water mines, long underground galleries to capture water springs (Juncà Ubierna, 1998; Stiros, 2006; English, 1998). With this background, the idea of underground water storage and conduction has been easily incorporated into daily life, and where geological characteristics and water availability allow, we can find interesting examples of water infrastructures. In this paper we present one of such cases. Before starting with the study of our specific case, it can be convenient to put in context the water underground infrastructures. We will refer to qanats and aqueducts, as examples more related with our case. Qanats are structures characterized by a double function of conveying water from underground springs or aquifers, and transport water to an area requiring its use, for irrigation or for human use. Qanats, with different names (Foggara in the North Africa, Karez in Afghanistan, and up to 27 different names in countries from Japan to Spain, including Iran and the Middle East, Hamidian et al., 2015) have played a relevant role in water capturing and transporting in dry climate areas, and in different parts of Spain, including the region of Valencia, there are some examples of these structures (Iranzo and Hermosilla, 2011; De Bustamante et al., 2015). While in Iran qanats achieve extraordinary sizes (up to 80 km, Hamidian et al., 2015) in the east of Spain lengths are not so important, and Iranzo and Hermosilla (2011) for an area 40 km east of Alcudia (our area of study) identify eight qanats with lengths under 500 m.
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Fig. 1. General plan of the network with indication of the cisterns.
The other infrastructures we will briefly comment are aqueducts, specifically the tunnels related to them. To some point a qanat is also an aqueduct, or at least one of his sections plays this role. The world of aqueducts is extremely complex and is out of the focus of this paper, but at least we have to mention that in the Mediterranean countries they have played a very significant role for supplying water to cities and irrigation systems. In the east of
Europe, we find well studied examples like the Eupalinos tunnel, in Samos (Greece) to cite only one (Stiros, 2009). In France there are magnificent examples, as the Lyon Roman aqueducts, where more than 3.8 km of tunnels have been constructed (Burdy, 2002). In Spain, as in the entire in Roman world, we find various examples of aqueducts requiring tunnels. We will mention only two examples. In Chelva, 60 km north of Alcudia, we can find the
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Peña Cortada, a nice example of an aqueduct using tunnels. In Albarracín, 150 km NW from our area of study, a Roman aqueduct includes a main tunnel of almost 5 km length (Arenillas, 2007). 2. The city of Alcudia de Crespins The small city of Alcudia de Crespins, in the center of the Valencia province, with 5000 inhabitants, lies in the Cañoles River Valley, at an altitude of 150 m over the sea level. Near to the city, the spring of ‘‘Los Santos” supplies water to the villages of the area. Materials in the underground of Alcudia de Crespins are formed by horizontal layers of different materials, from lake limestone to clay, including carbonated marls (the more frequent material) and also sporadic layers of sand, slime and even thin gravel and pebbles layers. The result is a homogeneous material, with dominant whitish tones due to calcium carbonate limestone and lake marls. These materials were deposited in a lake area formed by an important travertine structure, probably dated in the Medium Pleistocene, as it is superimposed (but included in the same alluvial sequence) to a river terrace of that age (IGME, 1976; Garay, 2015). This material is consistent enough to allow digging, but at the same time relatively easy to dig.
3. The underground water supply system In a moment that cannot be precisely determined, as ancient documents don’t cite this fact, a branch of the channel that brings water from Los Santos river, was constructed. This river is born in Los Santos spring, one and half km east of the network entrance point. The branch consists in a tunnel of about 130 m long, ending in an underground cistern (cistern 1.1 in Fig. 1). The cistern was under the Lord’s Palace that existed in the city since the 14th century. Today the Palace has disappeared, and the central place of the village occupies its location, but the channel and the cistern are still there, five meters under the surface. After this initial channel, the network of water supply tunnels started to grow. Only three meters before cistern C 1.1, in the left side of the tunnel a new gallery starts forming a 90° angle and drawing a curve around the cistern (proving that cistern 1.1 exists when this tunnel was excavated). From here, different branches of the network were excavated to serve water to other neighbors’ houses and to a well of public use (cistern 1.2). Under each house, a cistern was excavated. The public well consists in a cistern with eight shaped well, forming almost a double well, maybe to host some type of water wheel. Fig. 1 shows
Fig. 2. Network plan superimposed with the city view.
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As a result, better than a net, the general shape is like a tree. Only in one point we find a loop in tunnels, closed by rubble work, and this is not linked with the water circulation. 4. The galleries
Fig. 3. One of the authors (A. Fornes) surveying in a galleries junction.
the plan of the network, and Fig. 2 put this plan in relation to the city aerial view. The general structure of the network follows the following criteria: Water enters by the oldest part of the network and traverses under the city up to an open air channel on the other side of the town. From a main tunnel, lateral tunnels fed the houses’ cisterns.
The galleries were excavated using traditional methods, inherited from Roman and Arab times. These methods try to minimize excavation effort and time using multiple working faces. To do this, and using Roman terminology according to Vitruvio (VIII, 7) (Vitruvio, 2012), tunnels have regularly spaced shafts, named putei or spiramina that had a triple purpose: they allow excavating simultaneously from these shafts; they also had a ventilation function; and they served for material extraction purposes during the excavation process. These putei should be separated by one or two actus (one actus = 37.5 m). Qanat construction procedures are also similar, and shafts with the same functions can be found, having a spacing of 50–100 m (Stiros, 2006; English, 1998). The basics of this working procedure are to some point similar to today’s working schemes, with obvious technological differences. In our network these putei can be found in different places of the network, and they are not so frequent as should be according to Vitruvio’s recommendations due to the fact that cisterns also serve for this purpose. In any case, at least six of these wells can be found, marked with P in Fig. 1. If we take into account that cisterns’ wells may have the functions of putei, with a total of fifteen cisterns plus six putei, the mean distance between wells is 48 m, in the range of the above mentioned schemes (in Roman aqueducts distance is between 37.5 and 75 m, in traditional qanats is between 50 and 100 m). Tunnels walls show excavation tool marks, with a typical arch shape as effect of the excavation movement. Tool marks are about 3–5 cm wide, corresponding to a flat tool. No remains of tools have been found in the tunnels. There are also, in the walls, frequent small cavities used as light points. While the main tunnel section varies frequently, typical section is 0.60 m wide and 1.80 m high. Lateral galleries, driving to individual cisterns have frequently smaller width and/or high. The gradient of the network galleries is about 1.5/2 per thousand. The deep
Fig. 4. Two images of the galleries: Left, the main gallery, with a blocked entrance to a secondary gallery. Right, a lateral smaller gallery.
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of circulating water was about 30 cm, as can be noted from the waterproofing cover of tunnel walls. This cover is similar to Roman opus signinum (this material was a plaster or cement used for making pavements and for waterproofing aqueducts, and was made with ceramic tiles or pottery broken in small pieces, almost a powder, mixed with mortar and beaten down with a rammer (Matias et al., 2014)). In some places deep is greater, especially in the gallery cistern, where water seems to fill almost completely the tunnel, creating a reservoir, before reaching a level that permit the water to continue to other parts of the network. Total length of the network is 1010 m, corresponding to the galleries that can be visited. Twenty-eight galleries are closed by masonry, rubblework or rubble, meaning that the true length of the network is with certitude greater.
One of these closed galleries was also the exit of the network to the open air, essential in the operation procedure of the system. Figs. 3 and 4 show different views of the galleries.
5. The cisterns A total of fifteen cisterns were located and studied. Its approximate capacity ranks from 3.6 m3 (in cistern 4B.2, Fig. 1) to 67 m3 of the Palace cistern (C 1.1. in Fig. 1) and 75 m3 in the Gallery Cistern (C.5.1., Fig. 1). The total capacity registered in these 15 cisterns is 269 m3. Almost half of this capacity corresponds to only two of the cisterns (Palace cistern and Gallery Cistern). The third cistern in capacity corresponds to the old public well of the city, with 30 m3.
Fig. 5. Two images from the cisterns: Left, the double well in cistern 1.2. Right, an image of cistern 5.2.
Fig. 6. Cistern types in Alcudia.
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If we eliminate these three special cases, the rest of the cisterns correspond to domestic reservoirs for private use. For these cisterns, capacities ranks from 3.6 to 17 m3, with a mean of 8 m3. The general structure of cisterns corresponds to sub-circular plan of 2.5 m diameter, a deep of 1.5 m and a well to extract water almost in the center of the ceiling. Some exceptions can be made to this general shape: Cistern 1.1, or Palace cistern. It has a rectangular plant with one end rounded. Its dimensions of 8 3 m plant and 4 m deep denote its special use, as a palace in medieval times was more than a simple house. Cistern 1.2, corresponding to the city public well. Its plant is rounded, and of greater dimensions than regular (domestic) cisterns, but its main characteristic is its double well: the shaft formerly leading to the surface has an 8 shaped horizontal section (see Fig. 5 left and plan in Figs. 6 and 7). This structure is similar to those wells with a type of chain water wheel called ‘‘noria de cangilones”, in which the double well serves one for the descent of the water recipients and the other for the ascent (see Figs. 7 and 9). Fig. 8 shows a photo a water wheel of this type, still with the main wheel in position but nowadays out of use. Cistern 4.1. It has a triangular plant, completely out of the standard. The reason for this shape in unknown. Cistern 5.1, or Gallery Cistern. Two are the specificities of this cistern. The first one is that the same gallery of the tunnel has reservoir functions, serving both to feed the downstream parts of the network and as reservoir, accessible as cistern by the extraction well at the end of the gallery. The second one is that is the only part of the galleries that is below the general level of the water flow. The walls of the galleries are waterproofed usually about 30–50 cm high, but in the gallery cistern waterproofing is up to the ceiling. It is difficult to understand the role of this cistern in the network, and it has to be considered that it
Fig. 8. Water wheel of Bolnuevo (Murcia, Spain). (Image taken from http://www. regmurcia.com/servlet/s.Sl?sit=c,522,m,205&r=CeAP-10306-R_933_DETALLE_ REPORTAJES.)
seems to be relatively modern. Graffiti at the entrance of this section warns about the fact that the gallery can be completely inundated. Fig. 6 shows different cisterns: a typical domestic cistern (4.2), plus two of the non-standard ones (1.1 and 1.2). Fig. 7 shows the hypothetical reconstruction of the chain water wheel in the cistern of the public well (cistern 1.2), according to the testimonies of people from the city. A ceramic piece found in the cistern may be part of one of the recipients. In Fig. 8 we have a view of the water wheel of Bolnuevo (Murcia, Spain), from inside the shaft to the wheel. Similarly to cistern 1.2, an eight shape can be recognized in the section of the well. Fig. 9 is a drawing from the XVIIth century showing this type of water wheel (Lastanosa, 1601).
Fig. 7. Hypothetical reconstruction of the chain water wheel in cistern 1.2.
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entrance to the tunnels, with a gate located at the entrance to the network (see Fig. 1), and up today the access to the network. The gate was closed when the water exits by the other end of the tunnels, located about 300 m south of the entrance, and today disappeared, and from there used for irrigation. It was assumed that when the water exits, cisterns have been filled. Each house was responsible for the maintenance of its own cistern, and the Irrigation Association was responsible for the maintenance and cleaning of the tunnels.
7. Conclusions and final comments
Fig. 9. Chain water wheel in a XVII century drawing (Lastanosa, 1601).
While today only fifteen cisterns are accessible, the network includes other cisterns. At least 28 galleries are closed and eventually each one communicates with a cistern, or maybe more. We find the following cases: Some of the closed galleries are partially isolated from the main galleries, closing the passage with masonry, but leaving an entrance for the water that feeds the cistern. This entrance usually consists of a ceramic tube, and corresponds to ancient structures, compatible with the use of the tunnel network as water supply system. In some cases closures completely block the passage, and indicate the end of the function of the corresponding part of the network. Some are clearly related to changes in the streets of the city, as is the case of closures marked with B in Fig. 1, related to the construction of a new avenue: Closures are aligned and made with the same type of masonry. By the topography of surface and the houses distribution over this area of the network, probably only one cistern can be fed by each of this three galleries. In other cases the property of the house over the cistern closes the access tunnel when cistern became out of use, instead of simply closing the well as was the case in the accessible cisterns. Considering these non accessible cisterns, a conservative estimation of the total capacity of cisterns in the network increases this from 269 m3 (only accessible cisterns) to about 500 m3, considering that all these hidden cisterns are of domestic size. 6. Network operation Even considering that the network was abandoned in 1955, almost 60 years ago, we had the opportunity of interviewing the last person responsible for its operation. The channel feeding the network has the name of ‘‘setenes”, and is still in operation. This name indicates that this main channel distributes water for seven minor irrigation ditches, feeding each one day of the week. This secondary irrigation ditches were named upon the day of the week they are in operation, and these names have been applied also to the areas irrigated by each one. Testimonies explain that this domestic water supply network was fed every Wednesday. The procedure consists in opening the
To our knowledge, this supply system extended to a relevant number of houses in a village is unique. The system has provided fresh water to the citizens during centuries, and became obsolete when a modern drinking water distribution system was established. Its memory has been at risk of disappearing, and young generations didn’t know about it until these recent researches. Underground civil infrastructures are frequently underestimated, but they are a relevant part of the history of how humans have faced challenges of daily life. Its preservation starts with the public knowledge, and needs the support of public authorities. Avoiding damages to this (and other) infrastructure is a common responsibility of the community, starting by civil engineers and contractors who need the support of other specialists, as archeologist and historians. Acknowledgements The support of the Major of the city, Mr. Javier Sicluna, has been essential to these researches, as well as the information and help provided by Mr. Antonio Beltran, former member of the City Council, and other citizens of Alcudia de Crespins. To all of them and to the members of the Speleological Society La Senyera our sincere gratitude. References Arenillas, M., 2007. A brief history of water projects in Aragon. Int. J. Water Resour. Dev. 23 (1). Burdy, J., 2002. Les aqueducs romains de Lyon. Presses Universitaires de Lyon, France. De Bustamante, I., Sanz, J., Iglesia, J., Lopez-Camacho, B., 2015. Some Examples of Spanish Qanats.
A. Carrión, A. Fornes / Tunnelling and Underground Space Technology 51 (2016) 90–97 Prytherch, David L., 2009. Elegy to an iconographic place: reconstructing the regionalism/landscape dialectic in L’Horta de València. Cult. Geogr. 16 (1), 55– 85. Stiros, S.C., 2006. Accurate measurements with primitive instruments: the ‘‘paradox” in the qanat design. J. Archaeol. Sci. 33, 1058–1064.
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Stiros, S., 2009. Orientation and alignment of the 5TH C BC tunnel of Eupalinos at Samos (Greece). Surv. Rev. 41 (313), 218–225. Vitruvio, M., 2012. The Ten Books on Architecture. Courier Dover Publications.