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Client: Ajuntament de Caldes de Montbui

Project Architects: Cíclica [space, community & ecology] (Marta Serra, Elena Albareda) & CAVAA arquitectes (Jordi Calbetó)

Collaborators: Aleix Rifà (hydraulic engineer), Kim Arcas & Adrià Martín (Cíclica) & the gardeners association Associació d'Hortolans de les Hortes de Baix de Caldes de Montbui

Project Area: 370,000 m2

Project Date: 2015


At the edge of the small town Caldes de Montbui in northern Spain lie orchards that receive water through an old Roman irrigation system. In disrepair for decades, the system has now been rebuilt in a collaboration between architects and users and opened to the public.

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It is a warm October day. The summer harvest has finished, and most garden plots are cleared. There is not much movement around the orchards, but a few gardeners are starting to plant calçots – a green onion variety that is grilled over open fire to make the famous regional Calçotada. An elderly gardener greets us while passing with a bucket of cat food for the four-legged residents of the Hortes de Baix in Caldes de Montbui, a town 30 kilometers north of Barcelona.

Roman and agricultural past

The municipality of 17,000 inhabitants still preserves the charm of small Catalan towns and, despite its proximity to Barcelona, has not yet been affected by growing tourism, although there has been an increased effort to boost the local economy through the town’s potential as a spa resort. Aquae Calidae – hot waters – was how Pliny the Elder described the thermal springs of Caldes de Montbui in his chronicles Hispania Romana. With a temperature of 74 degrees, these are Spain’s hottest springs, and some of the Roman baths survive to this day.

Historically a region characterised by agriculture and horticulture, first descriptions of the garden system adjacent to the historical town centre and the watercourse Riera de Caldes date back to medieval times. Remnants of mills, public baths, washing places, and irrigation channels are witness to a past when the economic and social life of the town centred around the water cycle. The traditional water management for irrigation of the productive gardens was controlled through so-called comunidades de regantes, or irrigation communities, which would flood-irrigate the orchards by rotational turns. These are self-governed structures with Roman and Arab origins that can be found all over Spain to carry out the management and distribution of public watercourses, rainwater, and groundwater. The orchards of Caldes de Montbui were traditionally irrigated by surplus water from thermal washing places and rainwater directed to the main irrigation channel.

Regeneration of irrigation and landscape

As in many other places, traditional horticulture, water management, and associated knowledge have been lost over the course of the last century. The weakening of the social fabric with the collapse of the self-organised irrigation community was accompanied by the continuing environmental degradation of the gardens caused by water pollution through inflow of black water into the main irrigation channel, essentially turning it into an open sewage drain. The orchards moved out of the public view, despite their central location and visibility. The use of black water for irrigation posed a health risk, and the insufficient clean water supply for all gardeners on site led to the idea of reinstating the historic irrigation system to provide a solution to these endemic problems.

The project was initiated at the town council’s Public Space Round Table, a platform for citizen participation to discuss mobility and accessibility, landscape, environment, and water issues. It was subsequently developed and guided by project architects Marta Serra and Elena Albareda from Cíclica [space, community & ecology] and Jordi Calbetó from CAVAA arquitectes. Their proposal consisted of restoring the private horticultural landscape as a new public space to promote food self-sufficiency, co-designing the process in collaboration with the irrigation community and stakeholders and acknowledging the key value of traditional water management as a tangible and intangible heritage. The result has been not only a collective design process to develop an efficient and sustainable irrigation system in accordance with the gardeners’ needs and technical requirements, but also the restoration and new accessibility of a heritage landscape transformed into part of the public realm, thereby connecting the urban part of town to surrounding agricultural landscapes.

Technical renewals

Various minimalistic but efficient technical measures have been undertaken. The black water previously discharged into open drains is now separated from the rainwater, disconnected from the irrigation system and channeled directly to the municipal sewage system. The existing main irrigation channel has been covered with a new timber pathway to facilitate access to the gardens. Irrigation is supplied through surplus water from the thermal baths, private hotels, and public baths like El Safareig, a newly restored historic washing place. The excess water is captured and directed to the newly constructed collection pond for cooling.

An innovative pilot concept has been developed by the architects to absorb residual organic material in the pond through phyto treatment with macrophyte plants on floating gardens, thereby adapting to the fluctuating water levels of the pond. The water is then distributed to the reactivated irrigation channels through a gravity-fed water system to allow for the flooding of the orchards. The flooding turns are regulated by the former traditional organisation of irrigation areas by weekdays. As this system allows for a constant water supply all year, productivity of the orchards has increased and organic food production been enabled. All interventions by the architects have been carried out with great delicacy and sensibility so as not to impose on the appearance and identity of the self-constructed gardens and structures, retaining their sometimes improvised character. Materials already present on site – such as granite stones, ceramic tiles and bricks – have been employed, and existing objects replicated. The use of live willow for construction has been established.

Planning at eye level with the users

The methodologies used by the architects to study the various project aspects have been community- based participatory research and emancipatory action-research, as they explain. Exceeding mere negotiation and mediation between stakeholders, the architects have sought to act as equal partners with all collaborators involved in the process – currently around 70 gardeners, town citizens and the wider public – and to benefit from their respective knowledge. This created more room to experiment than the mostly rigid administrative processes of conventional community participation. The exchange of expertise, mediating between user groups and facilitating activities, therefore became a design tool to develop and communicate the project and to extend the role of the architect beyond design and construction. It furthermore included the re-introduction of a gardeners’ association, allowing for improved self-management of orchard irrigation, the transfer of previously almost-forgotten knowledge between generations of gardeners, and a better negotiation position with the council. A crucial part for the success of the project and resilience of the gardens, it has been an important step towards community-building.

Public consciousness

The significance of the recovered gardens, according to the president of the association, is not just enhanced self-sufficiency in food production, but an occupation – cultivating the land – that people can share with their fellow gardeners to bring together the community through new interest that the gardens have generated. In this way, a newfound pride in the orchards has grown among the gardeners. A renewed public consciousness regarding the orchards is also evidenced by visits of school classes with the purpose of educating children about food production and the social, environmental, and cultural significance of water.

The architects rate the qualities of the project in three levels of evaluation – political, productive, and civic. The political level consists of the continuous commitment of the local government to improve the space, the self-organisation of the gardeners, and the collaboration of these stakeholders on a political level. An increased output and introduction of organic agriculture through the use of clean water and a more efficient irrigation system, thereby closing the water cycle, reflects the productive level. And the integration of the gardens into the public realm, the recognition and restoration of local heritage and public memory, as well as the new validation of agricultural and horticultural spaces, forms the civic aspect of the project, revealing an additional invisible layer to the project.

Although there is a general consensus about the success of the project and improvement of the orchards, some gardeners voice concerns about side effects caused by increased numbers of external visitors. There were also the occasional difficulties in adjusting to the new restricted and regulated irrigation turns and to adapting the gardening and fertilisation regime to the changed water composition and temperature. Wastewaterfree irrigation also means fewer nutrients, which in turn leads to smaller tomatoes and vegetables; this has not been appreciated by all gardeners. Some time after project completion, it is quite obvious that this will be an open-ended process of negotiations, discussions, and compromises to manage and improve the gardens, including further construction of the walkway to connect it to the wider footpath network. The ongoing commitment in the orchards includes the architects, who consider themselves guardians of the project.

Process as value

A non-gesture project that is exceptional for its other dimensions was the characterization of the jury when it awarded it the European Prize for Urban Public Space 2016. Its value lies in the process as much as the outcome, and perhaps the gesture is manifested in the showcasing of water as a common good that should be self-governed, an understanding of the preciousness of water in times of climate change, and the rediscovery of traditional practices in horticulture, water management, and governance.

This article was first published in Topos Magazine, Edition 97 - Transformations, 2016.


Image Rights:

Plan © Ciclica&CAVAA, B/W Photos © Jose Tostoneone, all other photos © Adrià Goula