Mexico City Metropolitan Area has a complex network of water supply that faces a confrontational crisis of providing potable water for an overwhelming demand of 20 million residents, with an average daily consumption of one hundred and thirty litres per person. Political conflicts, economic declines and the ascension of social inequalities have resulted in the inadequacy of water supply, depletion of aquifers, maintenance inefficiency, distrust in water quality, high-cost substitutes, and far-reaching inaccessibility.
Four architectural projects explore the potential spectrum of urban water supply and consumption systems from the informal settlements on extreme morphologies, to mathematical concessions in existing metropolitan high-rises. Mexico City's future to achieve a state of salvation from its current predicament is to rely on additional and external sources of supply triggered with ingenious engineering, prudent utilization, prototypical local termini, and sustainable closed systems to mitigate the fragility in water flow.
Tlalocan
A utopian underground for access to water
Three giant sinkholes in the last decade emerged in the Mexico City borough of Iztapalapa caused by the leaking water pipes that dissolved the earth. Three days later, the sinkholes joined together to form large canyons. Since Iztapalapa is one of the furthest neighborhoods from the Cutzamala System—the major source of water distribution in Mexico City— inhabitants needed to find a more accessible water system to solve their daily lack of clean accessible water. The community of Iztapalapa constructed underground into the sinkholes to get closer to their nearest water source of groundwater and aquifers.
Tlālōcān is an inverted stepped pyramid neighborhood constructed from its own dug out earth work that leads down to the first aquifer. Water flows openly yet is controlled here so that the inhabitants live harmoniously with the natural environment that water shapes. The top edge of the sinkholes and canyons, where the pre-existing city surrounds, is buffered by a water catchment and filtration system that collects the excessive water runoff from the streets during the intense rain season and filters it down to replenish the aquifer. In the canyon cracks, the city above can observe the varying water levels below, inhabitants can view the water pipe infrastructure servicing the ground level of Iztapalapa, and the population can descend into the nine levels of Tlālōcān. The top three levels of sinkholes are dedicated civic spaces that connect the city above with the underground neighborhood. The water table, at approximately 80 meters below ground level, forms the transition to the housing area, at levels five, six, seven and eight. Here, ground water seeps through natural filtration layers into the contiguous pile retaining walls that create a water feature for the households to gather around. At the front of the houses, collected rainwater cascades down through waterspouts shaped in forms dedicated to the rain god, Tlāloc. Gravel paths, around the contours of each level, catch the water and filter it before it is collected into a canal along the walkway edge. Water is treated at the
lowest level of the sinkholes through water treatment facilities that purify the water to make it potable for residents to use during the dry season. The canyon cracks are surrounded by cisterns on the bottom level that contain the collected water and rush the water into the sinkhole treatment plants through their sloped channel. The water is pressured up through two tubes in each canyon crack for distribution for all levels. With the water level constantly fluctuating from the aquifer, ground water, and rainfall, the visibility and dependency create an underground utopia dedicated to water. The ubiquitous presence of water is a reminder of the Aztec empire cities.
In the future, Tlālōcān will expand by the continuation of sinkholes forming in Iztapalapa. The neighborhood has the potential to dig deeper for the growing population with more opportunities to replenish and utilize the second aquifer. Will Mexico City utilize its current natural water sources and climate to create a future metropolis based on its own culture and ideals on water?
Contribution by Jacklyn Mickey
Cuatro Culturas
Prototype for multigenerational dwelling Conjunto Urbano Nonoalco Tlatelolco
Tlatelolco is a place where each of the historical milestones of Mexico City are imprinted: the remains of the ruins of the city of Aztecs with its ceremonial center, the Colonial church of Santiago Tlatelolco and Conjunto Habitacional Nonoalco, the largest complex of the building company of collective housing in the 1960s. The complex was built under a certain social setting of the period of economic growth for the families of employees of state enterprises. The complex consists of commercial first floors, recreational and educational infrastructure and family apartments that are around 70-80 sq m.
The prosperous life of the complex came to a dramatic end with the 1985 earthquake, keeping a sense of tragedy in the remaining buildings - broken water pipes, unfinished repairs and permanently removed decorative elements. Privatization and restructuring of the tax system and institutions that maintained the buildings have led to a situation where the territory is simply exploited to its physical limits. Being built as an “economic miracle”, Tlatelolco has turned into a city of crime and disunity. Such unorganized and unmaintained exploitation of buildings led to a series of problems: courtyards littered with rubbish, abandoned ground floor, broken elevators, leaks in the pipe system that make up 50% of the water supply. The specific problem of high-rise buildings is the water access on the upper floors, as the pumping station operates at 40 percent of its capacity and is close to collapse. Eventually, residents of Conjunto Urbano either leave their homes or find themselves as hostages of their property. The paradox of such apartments remains in between the high unaffordability due to prestigious locations and earthquake-damaged buildings occupied by low-income residents, fearing being caught in their homes by the next earthquake. How can the residents of Conjunto Urbano maintain building and water infrastructures without government support? Can the high-rise buildings be improved and reinforced to turn from a reminder of the tragedy into a safe haven during an earthquake?
Collective use as a new culture “Cuatro Culturas” emerges on the wreckage of Mexico City, the outgrowth of state corruption and economic decline and the scarcity of water with the collapse of city general water infrastructure as a huge system broken by the previous earthquakes. Collective water facilities mitigates the dependency on the government's inefficiency to unite the residents of Tlatelolco in smaller communities with independent water cycles in their homes through an exchange of square meters for water access and building safety.
The initial stage to achieve this building transformation occurs as an earthquake reinforcement program by using water as part of reinforcement through rainwater catchments on the top of the building to counteract shear movements, through hydraulic elevator as safety exit during earthquakes, and through a new water supply system for rainwater catchment in the side pillars. The abandoned first floor occupies shared water facilities for the neighborhood, supplied by rainwater collected from the roof and courtyards. The higher levels with inadequate water access due to unsuitable pumping function as emergency rainwater facilities with showers, washers, kitchens, toilets, and greywater treatment tanks to guarantee water access during the transformation of flats from private family apartments to the collective dwelling for a group of inhabitants. The proposed reformation subdivides the existing structure of the apartment into three studios with common water facilities, following the existing construction skeleton. Shared water facilities strategically designed in the center of the floors leaving the possibility of using the existing standpipe to provide an alternate water supply source adhering to rainwater catchment and greywater treatment. Thus a new self-sustaining water cycle introduced in an existing building can provide water through the two extremities of Mexico City's climate by rainwater supply in heavy rainfall seasons and by operating as a closed water cycle through greywater reuse during dry months.
Prototypes of collective water facilities, such as kitchen, refrigerator, washing machine, shower, toilet and greywater treatment are prefabricated and designed to be grouped in different configurations. The greywater treatment block works as a platform for different units, providing pipes with the grid system of pipe connections. Thus the new prototypes can be embedded in different building types of Conjunto Urbano and similar districts of collective housing 1960s, as alternative solutions for water supply, thus stimulating affordable housing in the metropolitan city.
Contribution by Maria Finagina
Peripheries of Colonias Populares
Water supply for the informal settlements over the hills
Mexico City has had an extensive saga with water sensitivity and finds itself at its brim with paradoxical water shortages and flooding disasters due to unnatural obtrusions. Since entering the era of urbanization, the overwhelming water demand has caused scarcity of supply, maintenance inefficiency, poor water quality, high costs, and far-reaching inaccessibility, leading to a major water crisis, especially for the 480,000 people residing in the informal settlements in the conservation zone. Mainly located on the south-western foothills, these informal settlements, struggling due to social inequality, have deficient—almost extinct—water supply due to the many leakages amidst pipelines below the metropolitan city. With contaminated water from faucets and forced to rely on bottled water, tank trucks, local wells, or springs for water, the daily lives of these residents face disruption while spending one-fourth of the day and more than 10 percent of their income arranging water access. The Cutzamala Water Supply System, which provides 18 percent of Mexico City's water, transfers water from 60-154 km away, lifting it over more than 1000 meters, and terminates 300 meters below the foothills occupied by these informal settlements, circumventing and leaving them without potable water. The polarity of these settlements lies within a well-functioning, large-scale, infrastructural system of Cutzamala supplying purified water and the small-scale consumption of water on the other side of the spectrum. However, the problem arises in the in-between, intermediate scale of distribution where the negligence of maintaining interstitial infrastructures such as underground pipelines and pressure pumps become the factors causing the fragility of the distribution.
How can the control point in this centralized water system be shifted for the informal settlements to become independent of these interstitial infrastructures, liberating themselves from the metropolis below? Subjected to rainfall for seven months annually and located on a highly contoured terrain, can these settlements find local termini to capture alternative water sources?
The proposal aims to provide water supply to the informal settlements through two distinct networks that operate independently but complement each other while staying sensitive to the topological conditions. Firstly, it introduces a new tangent in the Cutzamala system with a modest aqueduct that follows the contour logic of gravitation and provides potable water through branched water mains to households in all informal settlements on the south-western foothills, without any expense on pumps. The pipelines within this network remain on the ground to provide better maintenance possibilities and avoid leakages, thus being prudent. Secondly, the proposal aims to capture rainwater on a communal scale through a new public spine that becomes a water collection device intersecting all houses, while providing structure and collectivity to the informality of these settlements. The two strategies tie up to channel a parallel route for water that follows the laws of gravity and provides alternative water supply systems as a prototypical self-built solution for all informal settlements on the foothills. The proposed water infrastructure becomes the ground for artificial topography for the informal settlements that remain undefined and lack collective interventions such as pavements and public squares to introduce buffering moments of infrastructure by creating privileged and scenographic spaces within its network for communal gatherings. These buffering basins provide water for consumption to a hierarchy of shared facilities such as Lavoirs for laundry, drinking water fountains, bathhouses, and shared kitchens supplied with treated rainwater, while the Cutzamala continues to feed individual households. The notion of water distribution through the communal public spine integrates with the terrain's morphology providing significant interstitial spaces in its urban design before feeding the objects, thus, resolving water shortage within the informal settlements and mitigating the previously faced fragility of the distribution network.
Contribution by Nishi Shah
Pipe Dream
Close-system water cycle in the self-built neighborhood
Pipe Dream, a closed-loop water cycle system, aims to lower the dependency on the municipal water supply by proposing the insertion of self-built water infrastructure into the existing fabric of Magdalena Contreras. The informal settlements in Mexico City are built in the conservation area and therefore, households in these neighbourhoods lack water supply infrastructure. The residents of Magdalena Contreras rely on water supply from municipal water trucks that fail to fulfil their daily water consumption. Moreover, the inconsistency in the schedule of these water trucks suppresses water consumption for the residents compared to any average neighbourhood in Mexico City. As a result, the residents of these neighbourhoods actively practice water recycling strategies by reusing water from dishwashers to clean the house, or by reusing shower water in a toilet flush while awaiting the next water delivery to fill up their tinacos.
The proposed self-built water infrastructure integrates the water recycling process on a larger scale to maintain water circulation within the settlement, thus creating a closed-loop water cycle system for water supply and consumption on a neighbourhood level. The topographic conditions of these informal settlements on the foothills are suitably natural platforms to distribute water from higher to lower elevations. The system feeds a cluster of 50-100 households by first collecting greywater from each house, transferring it into an artificial wetland that treats the water through a biochar filtration system, and finally allowing the neighbourhood to reuse greywater as a source of clean water supply through direct connection with existing plumbing facilities and the tinacos. Untreated greywater and rainwater are collected in a grey water tank before being delivered to an artificial wetland through the water pipes, while black water is collected from the septic tank in each household or sent to the neighbourhood septic tank where the solid waste is finally collected by a municipal waste truck and the liquid waste is delivered to the artificial wetland for further processing.
Through this process, greywater collected from the higher elevations is filtered into clean water for reuse in the lower elevations. Greywater from the lowest level is pumped back to the water facilities at the top of the hill to close the cycle. The water treatment facilities at the highest elevations supply excess water from the system to recharge the groundwater in the conservation area with a porous landscape. The proposal of a closed-loop water cycle system provides relevance to water both as input and output for the metabolism of the neighbourhoods. The proposed system of new water infrastructure consisting of a central septic tank collector, artificial wetlands, grey water tank, biochar filtration tank, and the clean water tank is deliberately designed on steep streets without car accessibility, in turn following the logic of gravity. Above-ground water pipes and infrastructural interventions thus become a new object in the self-built environment of these informal settlements.
