Climate change not only brings with it rising global temperatures, the proliferation of extreme weather events and rising sea levels. It also causes drastic changes in rainfall patterns that trigger floods and droughts. During the last months, and except for the storm that has irrigated Spain in recent days, Spain has become a paradigmatic example of this environmental tragedy: it rains little and, when it does, it rains badly (this April has been the hottest since there are records).
The result is an ecological and economic disaster (according to the Consorcio de Compensación de Seguros and the Geological and Mining Institute of Spain, flood damage is estimated in total at an average of 800 million euros annually). Thus, it seems that there is no alternative: politics, economics, science and industry must accelerate a change of model that allows the ecological transition towards climate neutrality.
Architecture, "an environmental discipline", as defined by Carson Chan, director of the Emilio Ambasz Institute for the Joint Study of the Built and the Natural Environment, must also contribute to the proper management of water. Chan is the curator of Emerging Ecologies: Architecture and the Rise of Environmentalism, an exhibition that will bring to MoMA in New York next fall a collection of models, photographs, sketches and other archival materials from projects conceived between the 1930s and 1990s with a strong ecological component.
"We see this exhibition as part of a broader debate about architecture's historical, present and future engagement with the environment," Chan tells The Architect's Newspaper. "This exhibition will help to understand the historical efforts made by architects to address the impact of humanity on natural systems," while allowing "to look at the present and the future in an informed way."
Next, we review how the old art of designing and constructing buildings and cities can become a powerful ally in the fight against drought at different scales, from the individual to the territorial. Users, architects, urban planners, municipal managers and politicians: we can all do something.
Domestic consumption: beyond everyday habits
An INE study reveals that the average water consumption of Spanish households in 2020 was 133 liters per inhabitant per day. According to the Ministry for the Ecological Transition, most of it goes to our hygiene routines (34%), followed by the toilet (21%), the sink (18%), the washing machine (10%), the dishwasher (consumes only 5% and its use can mean a saving of up to 60% of water compared to hand washing) and the kitchen (3%).
Individual responsibility appeals to the conscious review of our daily consumption habits. Control shower times, turn off taps while brushing our teeth or shaving, do not use the toilet as a bin and use appliances at full load; each of these practices can lead to individual savings of between 10 and 25 liters of water per day, as demonstrated in the exhibition Somos Agua, at the Canal Foundation until June 30.
These practices can be complemented with the implementation of simple home technology. Taps with flow limiters (a perlizador saves between 50 and 75%), toilets with double flush cistern, intelligent irrigation systems and appliances with low consumption programs (washing machines save up to 24%; dishwashers, up to 50%) favor the reduction of water consumption at home without the need for major transformations and at an affordable cost.
Architecture against drought: new materials and new strategies
The global water footprint per capita (the volume of water used directly in daily activities and indirectly to produce the goods and services we consume, including irrigation, industrial processes or transport) is estimated at 1,240 cubic meters per year (1.24 million liters), although according to the Spanish Water Information System, in the countries of southern Europe we double this figure, which oscillates around 2,400 cubic meters per person per year. Reducing it depends in part on how we eat (the production of a kilogram of beef requires 15,415 liters of water, compared to 214 liters of a kilo of tomatoes), how we dress (the elaboration of a cotton shirt needs about 2,700 liters of water, compared to 8,000 liters of jeans), and also how is the architecture in which we live.
A pioneering study by the Autonomous University of Madrid has estimated that the construction of a typical residential development (100 homes of 100 square meters each) in our country generates a water footprint similar to that which would be needed to fill 20 Olympic swimming pools. For their part, researchers from the University of Melbourne (Australia) have analyzed the water footprint of the most common building materials: metals such as copper, aluminum and stainless steel top the table; followed by wood, whose water footprint is almost double that of concrete; Finally, earthy materials, such as clays and ceramics, occupy the lowest positions. As with food, local and local materials will always have a smaller water footprint, since the costs associated with transport are considerably reduced.
Intermodal Station and Felipe VI Park in Logroño.Jesús Rocandio (Casa de la Imágen)
In addition to the materials used, there are other project strategies that contribute to water savings. "Although the use and number of users are decisive for the design of an appropriate installation, rainwater harvesting systems on roofs are relatively simple to implement in new constructions. With a simple treatment, this water can be used for irrigation and toilets", explains the architect Héctor Navarro, curator with Manuel Blanco of Somos Agua. "Other more complex options can also include the reuse of gray water (shower, dishwasher, washing machine) for the aforementioned uses and achieving multiple cycles of water use before returning it to the sanitation system," concludes Navarro.
In Spain, there are already some buildings that adapt their architecture to the complicated water situation of the country. This is the case of the Intermodal Station and the Felipe VI Park in Logroño, by Iñaki Ábalos and Renata Sentkiewicz, recently awarded the Asprima-Sima 2023 award in the category of "Best project in urban regeneration". The roof of the station is a park of 150,000 square meters that integrates drainage systems that collect rainwater and surplus irrigation for reuse, so that it hardly consumes water. "This, together with irrigation through the different underground channels that exist in the city, translates into a large area of air purification and an increase in biodiversity, which returns a natural condition to the urban environment," Ábalos explained to ICON Design a few months ago.
Urbanism in favor of water: compact, green and porous cities
The challenge for the future is to devise development models and policies that allow us to continue living in cities with less and less water. We know that urban density favors the efficient use of energy resources, infrastructures and services necessary for life in a city. Thus, as a general rule, we can conclude that, the greater the compactness, the lower the water consumption.
Another key strategy is the renaturalization of cities. "In a forest, 95% of rainwater is absorbed by the soil and 5% is converted into runoff. However, in urban environments with traditional waterproof pavements, these numbers are reversed. This is the reason why, in scenarios of excessive rainfall, cities end up flooded, "explains Navarro.
Exhibition 'We are water'. Miguel de Guzmán and Rocío Romero
The design of porous cities involves installing soils with natural vegetation adapted to the water reality of the environment (which are the most permeable, followed by those of gravel, sand or clay) and asphalt and paving stone solutions produced with filter materials (or hybrid systems that fill the joints with porous materials such as grass or gravel) that serve, on the one hand, as a rainwater collection system and, on the other, as a defense against torrential deluges and floods. Natural soils also prevent the drying up of underground aquifers and effectively reduce heat island effects.
Finally, cities must also allocate resources for the construction of new infrastructure for water management. "The modern Madrid that grows in the mid-nineteenth century with the expansions was possible thanks to the creation of the Canal de Isabel II, which brought the necessary waters for the city and that today captures, manages, treats and regenerates those used to irrigate its parks and streets and return it clean to nature. We can only understand the cities of the new millennium in this context", explains Manuel Blanco, curator of Somos Agua and director of the School of Architecture of Madrid (ETSAM). "To be able to live in them we need good sustainable practices in their distribution, in their collection, in their use and purification, and in their return to the natural environment. Architecture is water because without it it is not built, and without it, sustainable urban life on our planet is not possible," concludes Blanco.
They are expensive installations, such as water treatment plants, desalination plants (in the case of coastal areas), pipeline systems and treatment plants, which have traditionally been perceived as necessary evils, so we opted for strictly functional architecture without charisma, which we preferred to hide from citizens. Today, however, more and more people are taking advantage of these commissions as an opportunity to become symbols of development and commitment to the environment. This is demonstrated by projects such as the treatment plant next to Lake Whitney (Hamden, Connecticut; 2005), by Steven Holl and Chris McVoy, which fuses a stainless steel building shaped like an inverted water drop of 110 meters in length with a public park of 4.8 hectares near Yale University.
Interior of the treatment plant of San Claudio.Mariela Apollonio
San Claudio treatment plant.Mariela Apollonio
Another good example of this environmental pride is the expansion of the San Claudio treatment plant (near Oviedo, 2016), designed by Padilla Nicás Arquitectos. The intervention consists of the volumetric and material definition of buildings with broken profiles, in clear harmony with the surrounding constructions, which are covered with embossed aluminum and translucent polycarbonate with the intention of dematerializing their volume and reducing their impact on a privileged landscape. "Our goal is to provide new buildings with volumes that respect the rural environment in which they are located, and that meet the needs of use and heights demanded, using low-cost materials and simple maintenance," explain its authors.