The City Council of Segovia has awarded the company ‘Técnicas para la Restauración y Construcciones SA’ (TRYCSA) the service contract for the complete cleaning of the upper vegetation of the aqueduct of Segovia for an amount of 39,203.48 euros (VAT included), plus 9,000 under budget for which it launched a call for tenders (48,399). December.
“The works, which have an estimated duration of around three months, will begin before the end of the year”, indicates the town hall in a press release sent on Saturday, while the major part will be carried out between January and March. If this is the case, the optimal period of intervention indicated in the documentation itself, which runs from March 1 to April 15, would therefore not be expected. Basically, because from April 15 begins the reproduction of the birds that frequent the monument, but it is assumed that acting too early can reduce the effectiveness of the intervention itself, since the plants are not sufficiently developed. Progress will be made on the fly in these months to come, in any case.
In this sense, the Town Hall recalls in its press release that the intervention will be carried out by “an expert specialist in restoration so that the treatments carried out are effective and do not damage the stone in any way”. In this sense, the winning company entrusts the contract to Carlos Sanz Velasco, a graduate in fine arts, specializing in the conservation and restoration of cultural property. In summary, the removal of existing plants and their elements will be treated, the treatment of plant remains and the elimination of residues on cornices and cavities, among other interventions, simultaneously checking the condition of the stone in the intervened areas.
In this regard, some studies on stone analysis from the Geological and Mining Institute of Spain (IGME) will be incorporated. In addition, the contract includes the preparation of a final report regarding the works and treatments carried out in the execution of the intervention, as well as the conservation needs detected.
The process of integral clearing of vegetation in the aqueduct will involve the use of auxiliary means such as lifting platforms that allow access to all exposed facades, including the upper parts of the monument. This is to minimize bioweathering in the stone of the monument.
“The appearance of the upper vegetation in the aqueduct of Segovia is an annual and recurring cyclical phenomenon; it affects the whole monument because it is permanently exposed to the elements due to its configuration and nature”, states the municipal Council. “It is a well-studied problem in all monuments and can affect stone materials due to the mechanical or chemical action associated with the presence of these plant elements.”
“Deterioration caused by vascular plants (vegetation of a certain size, different from lichens and bryophytes such as mosses) is a consequence of the growth and penetration of roots, which are introduced into building plants through the joints or in mortars and areas with less physical resistance, although this is also not the most favorable environment for the development of plants”.
“After the deep storm that was called Philomena, in January 2021, optimal climatic conditions occurred that caused an increase in the colonization of vegetation in the aqueduct, an increase that leaves the presence of vascular plants, roots , of plant remains in the monument and some latent elements inserted in the plant; all of them must be adequately treated to prevent their growth and development or so that they are not a substrate for the development of new plants”, continue the same sources. “Although the damage caused by vegetation is not relevant, it is a slow process on which measures must be taken within the framework of the maintenance of the monument to prevent the proliferation of the phenomenon, taking into account the fact that the last clearings of the vegetation took place in the 90s of the 20th century, in the restoration undertaken by the Junta de Castilla y León”.