Sete Fontes: a Challenge to Promote the Heritage Legacy andFacing Water Sources Scarcity in the city of Braga-Portugal

Abstract

An ancient drinking water supply system, called Sete Fontes (Seven Springs), was built in the mid eighteenth century in the city of Braga. The system is composed by underground galleries, cisterns, waterspouts, fountains, and (covered) stone aqueduct channels with about 3500m long. This national monument, still existing and active, preserves both the original memorial role (representative of a boost to urban and baroque architecture), and the original function(improvement of quality of life), being a witness of the evolution of hydraulic engineering concepts, which greatly contributed to the improvement of urban infrastructures and the protection of public health. This paper also presents an overview of the history of the water supply system of the city of Braga, from the Roman period to the contemporary age, with special focus on Sete Fontes water sources characterization (morphological, hydrogeological, hydraulic, and water quality). This heritage legacy is invaluable not only for its history and cultural significance, while maintaining its authenticity and integrity, but also due to its confirmed water quality that can be an added value, taking a new relevance to address future scarcity scenarios of safe water sources in a climate change context.

The “Sete Fontes” groundwater system (Braga, NW Portugal): historical milestones and urban assessment

“…Nevertheless, the growth of the urban centre in the first and second centuries demanded more complex water-supplying techniques ) and a more productive source with higher water quality. Considering the several archaeological evidences found in the city (Lemos 2008;Teixeira 2012) and in the outskirts (Braga and Pacheco 2013), and taking into account the number of public and private baths and other water-related public buildings, the existence of, at least, one aqueduct, which could supply water from outside the city, most likely from the Sete Fontes region is assumed, according to the morphological, hydrogeological and archaeological evidences (Lemos 2008;Costa 2012;Rodrigues 2012;Teixeira 2012;Vieira et al 2016).…”

“…These modifications converged in a reduction of the water consumption. Considering the size of the city in the High Middle Ages, and the collapse of the Roman water supply system, the intramural drinking water system should have been almost exclusively dependent on wells (Vieira et al 2016). Some medieval documents reveal not only the concerns to improve the water abstraction capacity (looking up to new sources or returning to some already existing), but also real difficulties to face when the water demand increased in the urban centre, due to the Braga city's growth in the fourteenth century that implied the boundary enlargement of medieval rampart (Martins et al 2011a).…”

“…From the second quarter of the fifteenth century, these water sources (within the walls) demonstrated to be insufficient to meet the increasing water demand (Vieira et al 2016). Therefore, it was necessary to reactivate old or find new sources on the outskirts north of the city but less than a land league (about 5 km) away (Fig.…”

“…Since ancient times, it has been extremely important to ensure that water abstracted in remote areas could reach a main reservoir (called the matrix), from which water could then be distributed to different strategic distribution points within the city Vieira et al 2016). The Romans used a water reservoir (castellum aquae or castellum divisorium) that received water from aqueducts and then distributed to fountains and bathhouses covering different areas of the city.…”

“…6), near the city walls, has been referenced. This main reservoir was a stone structure, located near the medieval rampart, which had in its interior a great arch for water entrance, perhaps to perform water aeration (Vieira et al 2016).…”