The Journey of Water

Moa Wintzell, Architecture

The Journey of Water

Madrid is on the brink of climatic disaster. Spain, one of the warmest and most arid countries in Europe, is only set to become warmer. History has seen people – and architecture – increasingly turn their back on the natural systems on which they depend – celebrating the subjugation of nature over city. As society becomes less reliant upon nature it separates itself, spiritually and practically, from its earthly context. At the centre of the struggle to make Madrid habitable has always been an elemental strife for our most important resource: water.

This thesis aims to reintroduce a fundamental, forgotten part of nature to the urban fabric. Drawing from both the earth and history, it seeks to rebuild a ‘Viaje de Agua’ in Madrid – in celebration of nature. The Journey of Water investigates the role of architecture in shaping not only the built world, but our interaction with it and our societal values. It is a thought project questioning the priorities of architecture and urbanism within a failing ecosystem, supported by real strategies for changing the urban water system – not just mitigation strategies.

The architecture forms a landscape within the historic centre of Madrid which is capable of treating greywater from the 1.2 million inhabitants of inner-city Madrid – placing the treatment process in full view of its beneficiaries – architecturally enhancing its symbolic qualities to increase awareness and provide a positive impact on both city and nature. It tests architecture at an infrastructural level, taking inspiration from the city’s existing cultural legacy of Roman and Moorish influences.

The journey begins and ends at the first historic gate of the city, and the remnants of the original city wall. As the water is treated, it moves through a Museum of Water, an Auditorium, a system of reed beds and control stations symbolising characteristics of water such as Rain and Mist, amidst Orchards of olives, oranges and almonds, to end up in a Bath House situated atop a Water Reservoir. The water is then recirculated through the Aqueduct to the Garden, the River, the Groundwater and the People of Madrid, completing an urban cycle intended to work with, rather than despite, its natural counterpart.

The thesis is intended as an example of what sustainable architecture could be if it was given the same prerogative as modern capitalist architecture. It includes architectural judgements which sometimes diverge from what would be the most strategic solution – this is intentional. Being placed next to the Cathedral and Royal Palace, it echoes their ostentatious scale, becoming a forceful symbol of Nature as opposed to Governance or Religion. Similarly to Roman infrastructure and authoritarian architecture, scale is a tool to convey importance. The aqueduct – the line across the landscape – is purposed as a symbol for the city, not just the site.
Meanwhile, Moorish values have influenced the more proximal experience; clues within a landscape, a higher level of detail, the greenery and the pavilions. The reverence for water is often the quiet interactions; watching the ripples across a still surface, hearing the trickling of a fountain or walking through mist across dewy grass. Amidst a bustling metropolis these are lost experiences Furthermore, within a city as short for water as Madrid, it seems an unlikely occurrence. The benefits of a green space with a controlled source of reusable water is that these encounters with water actually have a positive effect on the environment – the programmatic objective being to return water responsibly to the hydrologic cycle, and the ultimate object being to encourage sparser personal use and affect societal change.

Natural Water Cycle

Understanding the Resource

The natural cycle of water is a journey without end; a story of renewal, life and prosperity. Envisioned as architecture, this means bringing back the idea of circularity: closing the loop, from collection to reuse.
Water is fundamental to life on Earth. 70 % of the planet’s surface is covered by water, but only 2.5 %
of it is freshwater.

Out of this, only 1 % of the freshwater is easily accessible. All in all, 0.007 % of the planet’s water is tasked with sustaining the life of nearly 7 billion people.

When we talk about the water crisis, it is not a question of ‘running out of water’. The amount of water remains the same, but availability varies. The continuous cycle of water also carries with it pollutants and pathogens.

The challenge, therefore, lies in conserving, managing and distributing the water we have. Regardless of our urban strategies we all rely on the hydrological cycle.


Condensed water vapour that falls to the Earth’s surface. Most precipitation occurs as rain, but also includes snow, hail, fog drip, and sleet.

Surface runoff

The variety of ways by which water moves across the land. This includes both surface runoff and channel runoff. As it flows, the water may seep into the ground, evaporate into the air, become stored in lakes or reservoirs, or be extracted for agricultural or other human uses.


Water flows vertically through the soil and rocks under the influence of gravity.

Groundwater & Subsurface flow

Water flowing underground in the vadose zone and aquifers. Subsurface water can return to the surface at a relatively lower elevation than its infiltration point under gravity or by being pumped, or filter out into oceans. Groundwater moves slowly and takes a long time to replenish, and may remain underground in aquifers for millennia.


Energy from the sun heats up the surface water of the Earth, causing water to evaporate and rise into the atmosphere.

Plant uptake

Trees and other plants absorb water from the ground – both surface runoff water and natural soil moisture.


Transpiration is the process of water moving through plants. The vast majority of water absorbed by plants is lost to the atmosphere – only a small portion is used for growth and metabolism. The transpiration process also cools the atmosphere. Large forests can even produce enough water vapour to create a cloud cover.


The transformation of water vapour to liquid water droplets in the air, creating clouds and fog.

The state change directly from solid water (snow or ice) to water vapour by passing the liquid state.

Urban Water Cycle

Water gathers naturally

Water gathers in nature according to the hydrologic cycle; evaporation from surface water and transpiration from plants return water to the atmosphere, which is then returned to the earth’s surface as rainwater. Surface- and rainwater also filters down and slowly recharges the groundwater. It is important to note that plants don’t “consume” water: 97-99.5 % is immediately returned to the atmosphere, creating a cooling effect and contributing again to the natural water cycle.

Human collection

Urban water systems tend to collect water upstream or in higher altitudes in reservoirs, dams or through extraction of groundwater. The amount of water needs to be carefully monitored to not exceed what nature can cope with. Any water extracted from human use ultimately reduces the water level in natural rivers.


After collection, water is treated to potable use through a range of mechanical, chemical and biological processes. Developed countries have a very high bar for what is considered clean water but even with today’s systems it is impossible to remove all contaminants.


Treated water is stored in service reservoirs (water towers, underground storages, both in urban and extraurban settings) before being distributed through piping to the end user.


Collected municipal water supplies residences, businesses and industries. Some users may collect their water privately; in Spain, private families and businesses accessing groundwater illegally is an acknowledged problem, and the exact amount of water being extracted purely for personal use is hard to determine. This is not particularly common in cities like Madrid, where the water supply system is readily available. However, wasting water increases when living in cities, and we spend 5-7 times the amount we actually need to get by (140 l as opposed to 20-30 l/day).

Waste treatment

After use, water is divided as greywater (kitchen, shower and sink in bathroom, appliances and other water sources) and blackwater (toilet, sewage, certain but not all industrial water). Currently, the main aim is to treat greywater to sufficient cleanliness to not harm humans and animals in nature – predominantly by removing pathogens causing disease. Blackwater is not generally recycled at all, but bigger particles containing dangerous pathogens require decomposing before discharge is possible. Some greywater is recycled and used in industries or for irrigation in parks. Madrid has a comparatively good system of using reclaimed water for irrigation.


Greywater and blackwater is more or less unceremoniously discharged in rivers downstream from cities. The water still contains contaminants and human nutrients that in large quantities have devastating effects on aquatic life. In particular blackwater and runoff water from fertilised land adds dangerous amounts of nitrogen and phosphorus to rivers, lakes and seas, resulting in eutrophication; in Europe, 53% of all lakes are eutrophic. This increases algal and plankton bloom, creates problems for water treatment, poisons and kills fish (reducing fishing yields), decreases biodiversity and generally destroys the aesthetic value of water masses.

Combined Water Cycle

Prediction of hydric resources on the Iberian Peninsula:
2030: an average decrease in hydric resources of 5-14 %
2060: expected decrease of 17 %
Source: MAPAMA 2005


Rainwater is an untapped source of water which in the city isn’t naturally filtered through the ground because of hard surfaces. After collection, it can be treated for use in irrigation or drinking.


The usage of water initially remains the same, but the concept of the water gardens is to create awareness and regard for water to promote a decrease in usage, primarily in residential areas. Potable water previously used for irrigation can be redirected to residences and businesses first.

Water Repository

The water basilica and subsequent reed bed system collect grey- and blackwater, treating it to different levels of cleanliness according to its use. Water being used in the garden does not need to be deprived of nutrients as plants can bind these. Upon second reuse, this water will therefore need less treatment. The basilica is the main structure and thus houses the most technical parts of the treatment, in combination with civic functions – cementing the connection between water treatment and involvement of the public. The aqueduct acts as a distribution system of clean water to the orchard and all other water usage within the journey.
groundwater recharge

Water can be responsibly sourced from the water gardens and fed back into the city, reintroducing the network of public fountains which were formed by the ‘viajes de agua’ / water journeys. At these points, efforts can be made to pump rainwater and sufficiently treated waste water back into the underground aquifers, counteracting the detrimental effects of hard city surfaces.

The orchard provides a sanctuary within the city and embodies water’s aspect of ‘giving life’. Treated blackwater can be used for compost – although this requires a rigorous treatment it is a safer, more controlled way of dealing with pollutants damaging our ecosystem. Greywater can be used for irrigation directly after being treated in reed beds strewn throughout the orchard. The water is returned to the atmosphere and the natural cycle of water as vapour through evapotranspiration.

reusing water

Excess water can be treated again to be reused or stored for dryer seasons. Having all functions of the circular water journey in one controlled environment enables a more economic system for reuse and to eliminate waste. This also means that the system can ensure that no dangerous contaminants are released into the river.

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