Urban Nascentes Towards a new celebration of headwaters in São Paulo São Paulo, Brazil Yuan Zhuang
“Water eye on the wall” Rin, São Paulo, Brazil Photo courtesy Existe água em SP (Feb, 2018)
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BIOGRAPHICAL SKETCH Yuan holds a Master of Landscape Architecture from Cornell University and has most recently worked at the OLIN Studio and The Cultural Landscape Foundation as an intern. Yuan received her bachelor’s degree from Denison University with a double major in Communication and Economics, then she moved to Arizona and worked on regenerative design projects as an apprentice to a local architect. Yuan is interested not only in design of landscapes but also in writing of landscape architecture. Experiences of living in Iceland, England and the Netherlands have made fundamental impacts in her way of perceiving and approaching landscapes. Now she is excited to move New York City and work at Snøhetta and hope to take her future Grand Tour in Latin America to continue bringing different landscapes into life.
Yuan Zhuang August 2018 Design Thesis Presented to the Faculty of the Graduate School of Cornell University Master of Landscape Architecture Advisors Brain Davis, Cornell University Paulo Pellegrino, University of São Paulo
ACKNOWLEDGEMENT Thank you to the following: Brian Davis – for constantly pushing me hard with higher standard but also guiding me through tough times with your immense knowledge and sharp intuition over the past twoyear intensive collaboration on courses and researches. Thank you, for being a great mentor and a friend. Paulo Pellegrino – for inviting me to the TUM workshop and LABVERDE at FAU USP in São Paulo, walking with me through the site and feeding me with constructive insights on water management and landscape design in in São Paulo. Wenjun Xu – for every all-nighter well-spent with my studio twin sister who has been always working hard by my side and reviewing my concepts and drawings with the most critical mind. I also want to express my deepest gratitude to my colleagues Newton Becker, Daniela Rizzi, Amelia Jensen, Yuting Liu and Daisy Hoyt who have been supportive and inspirational to make my trip to Brazil rewarding and this project strong.
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CONTENTS 01 INTRODUCTION | SPRING IN SÃO PAULO
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Abstract
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Megacity at headwaters
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Presence of water in São Paulo
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River channelization
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Urban growth and population
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Natural spring in São Paulo
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Urban spring in São Paulo
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Spring discovery: water initiatives as a cultural practice
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02 THEORY | TOWARDS ATOMIC URBANISM
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Criticism of modern planning
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Comtemporary Paradigm: Green infrastructure
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Atomic urbanism
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Nascentes: basic unit of atomic urbanism
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Emergence of water
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Matter of scale in urban setting
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03 METHODOLOGY | WHERE WATER IS PRESENT
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The site: Jardim Boa Vista
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Urban condition: mixture of spring and runoff
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Analysis of urban flow
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Field work: observation
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Field work: defining strategic location
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04 DESIGN | WATER AS FIGURE
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Intervention location
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Nascente master plan and sections
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Infiltration and flow diagram
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Monumentality of pools
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Hydrological function
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Ecological and social function
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Nacentes as means of organizing urban fabric
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Conclusion and urban implication
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Work cited
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INTRODUCTION | SPRING IN SÃO PAULO
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Nascente : lugar onde nasce um curso d´água - The place where water is born Nascent- : Nascens, the present participle of the Latin verb Nasci - to be born
“Nascente used by local people of the Zona Leste” The East Zone, São Paulo, Brazil Photo courtesy Existe água em SP (Feb, 2018) Translation sources: Cambridge Dictionary Portuguese-English Dictionary, Merriam-Webster Dictionary
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Brazil
State of São Paulo
São Paulo Metropolitan Region
ABSTRACT As climate continues to change, São Paulo, one of the largest and richest cities in the world, has been facing water crisis over the past decades. Flashing floods hit the city during monsoon seasons from November to February, then follows severe droughts during wintertime from June to September, the extreme climate scenarios entangled with rigidly-engineered water management system have long changed the relationship between pualistanos and local river networks in São Paulo. Over 300 rivers and streams are buried underground within the city throughout the process of urbanization. Uniquely, São Paulo is one of few megacities built on a territorial condition of headwaters with hilly topography and a converging river valley. Even without precipitation events, sources of water scatter across the metropolis with natural springs emerging at people’s backyard. However, the natural movements of spring water forming potential headwater streams are confined, disturbed and dominated by infrastructure and urban structures such as drainages, streets and buildings. Every drop of water is treated relentlessly the same as runoffs and drained out of the city as fast as possible. Under
this circumstance, the primary objective of this research is to investigate into the idea of nascente in urban settings and develop a theory of atomic urbanism by reintroducing hierarchy of water to the existing urban fabric. To do so, the project repositions runoffspring water mixture as the source of headwater that is subjected to design intervention to provide hydrological, ecological services and social engagement in the context of São Paulo. Examining the case of Jardim Boa Vista, a neighborhood located at the peripheral of the São Paulo metropolis, the research proposes a design of urban nascente and a neighborhood master plan to recover local headwater networks while creating public space to re-engage the surrounding community to live with water in everyday life.
Key Words: nascente, spring, headwater, runoff, stormwater management, cultural landscape
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B re illin se g rv s io r
Ri ve r s
Ta re ia se cu rv pe oi ba r
T do ietê w R ns iv tr er ea m
nh
Pi
G re ua se ra rv p ir io an r ga
T up ietê st R re iv am er
ei ro
The Tietê River, and its tributary, the Pinheiros River are the natural boundaries of the rich and vibrant areas of the city. Most urban activities are concentrated within the bounds of the rivers whereas favelas sprawls outwards.
ALTO TIETÊ WATERSHED 5,985 km2
Watershed boundary River
SÃO PAULO CITY 1,520 km2
Pre-channelized river Buried rivers and streams Waterbody Floodplain
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MEGACITY AT HEADWATERS
São Paulo is located in southern Brazil. It is the world’s seventh-largest city by population and the second most populous metropolitan area in the Americas. It is home to almost 20 million inhabitants and represents 19.4 % Brazil’s national economy (The World Bank, 2012, p.3). The Tietê River and its tributary, the Pinheiros River, were once important sources of freshwater and leisure for São Paulo. However, during the second half of the 20th century, industries dramatically increased its number and their wastewater discharges heavily polluted rivers in São Paulo. Rapid urbanization also prompted channelization and hardening of watercourses that permanently changed conditions of rivers and its natural activities, distancing people from rivers and their tributaries. The impacts of Climate Change further complicates the territorial conditions of the city. Over the past decades, São Paulo has been facing severe water crisis. Flashing floods during monsoon seasons could sweep the city in a few hours and gush everything down the hill with fast-moving currents rolling solid garbage bags or ruined furniture. Several months later, the city could be devoured by “seca” [drought] with thousands of households running no water in their tabs. The extreme climate scenarios entangled with rigidly-engineered water management system and unplanned land use continuously increase loss of natural river networks in São Paulo. Over 300 named rivers and streams are buried underground within the city throughout the process of urbanization. Referring to historical maps prior to 1930s and observing in the city, Rios e Ruas has mapped a totaling of 3,000km buried rivers and streams, with more than 70% of which are headwaters (Rigby, 2015). The map of buried rivers and streams is incorporated into the watershed drawing to the left to illustrate São Paulo is one of few megacities built on headwaters. Discussions with local scholars and residences proved that natural springs emerge at people’s backyard so that even during dry seasons, hidden sources of water scatter across the metropolis. However, the natural movements of spring water forming potential headwater streams are confined, disturbed and dominated by infrastructure and urban structures such as drainages, streets and buildings. Oftentimes, the spring water is mixed with surface runoffs and waste water discharges and drained out of the city as fast as possible. “estúdio laborg maquete projeção mapeada rios descobertos sesc vila mariana e ruas são paulo” Photo and model courtesy Rios Des.Cobertos Photographed by Estúdio Laborg (2016)
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PRESENCE OF WATER IN SÃO PAULO
São Paulo has more than 300 rivers that are polluted, buried and mixed with sewage. If you walk in the city, there is a watercourse not further 300 meters away from you." - Geographer, Luiz de campos Jr. Rio Verde by Cidade Azul “Concrete enbankment of Tietê river with underground river opening for converging”, (March, 2018)
“Spring water mixed with
Water management in São Paulo is challenging as the city is facing a mix of issues regarding annual flood, drought, drinking water scarcity as well as pollution in regards to public health. Once visit the city, one would find water is everywhere but presented in an unattractive manner. In March 2018, I went to São Paulo for the first time and was deeply disturbed by the massive engineering networks encompassing the Tietê River when the cab drove me along the highway 116 from the Guarulhos airport to the city center. The 12-lane highway on both sides of the river as well as concrete banks defined the margin of the river. Channel and pipe openings of various sizes cut the pristine stretch of the concrete wall, with some stream names labeled on a few larger openings. Rivers and streams has become familiar aliens chained underground in the city. Neither visual nor physical access is intended for the general public to engage with the Tietê River on a daily basis. When inquired about the Tietê, people lamented the pollution, the odor and mosquitoes like the river has no positive impact on the city life. Most small tributaries of the Tietê and the Pinheiros are paved over within the urban core to prioritize traffic. Although hidden, water still finds its weak expression through road cracks, moss on curbstones or a transient appearance at discharge trenches near houses. In this case, the urbanization process has created a new complex hydrological circle consisted of runoffs and drainages. According to Hough (1995), runoff in urban area might constitute up to 85% of the precipitation whereas in forested land, runoff is generally absent (p.39).
Disappearance
Emergence
runoff in gutter”,
"Changing hydrology from
Screenshot from video "Rio
urbanization", p.40,
Verde" by Cidade Azul,
Michael Hough (1995),
(2016)
Cities and Natural Process
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RIVER CHANNELIZATION
1905 historical map of São Paulo showing urban growth in relevance to river curvature
Throughout the 19th-20th century, the primary strategy that accelerated inhabitation of the city was through straightening and channelizing of São Paulo rivers. In 1890s, Várzeas Sanitation Commission was formed and they proposed a report recommending channelization of urban rivers including Tamanduateí and Tietê. The project was begun but soon paralyzed due to financial struggles of the institution. However, the interest of regulating the rivers and occupying the várzeas remained appealing to various agencies and firms. Impactful actions took off in 1920s following the creation of a new institution – The Commission for Improvements to the Tietê River. Collaborated with the state government, the institution proposed a set of projects including construction of bridges and avenues along and across the São Paulo rivers. From 19201950, massive engineering efforts were invested to create large and deep waterways to not only move barges but also increase flood capacity ((Davis & Jensen, 2015). The drawing to the left illustrates the channelization and rectification of the Tietê River over the past 113 years. The river has almost completely lost its original geometric complexity and floodplain. Now the margin of the river is surrounded by 12 lanes of traffic and defined by concrete belts of embankment with lines of pipe mouths arrayed to the brim of the water level, receiving a mix of suspended solids from drainages and sewages.
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URBAN GROWTH AND POPULATION
1881 1.6km2 0.03%
1905 25km2 0.42%
1929 100km2 1.67%
1949 270km2 4.51%
1974 1,300km2 21.72%
2015 2,140km2 35.76%
Watershed boundary Major highway Roads Floodplain Park Industry
In the meantime, the population of the municipality of São Paulo has multiplied approximately 50 times, from 240,000 in 1900 to 10.9 million in 2009. Since 1986, the city radiated out from a dense urban core near the confluence of Tamanduateí and Tietê rivers. By 2013, the densely built area had shifted southwest towards the Pinheiros River with highrise residential building erected. In contrast, fast growth of suburbs spread throughout the peripheral of the city over the past decade with 1.7 million population increment. It is worth of notice that much of the suburban growth happened in favelas, in which case poor people occupy steep hillsides or floodplains unsuitable for constructions to build congregated shelters (UNHabitat, 2010). 15
NATURAL SPRING IN SÃO PAULO
Although immersive change has been made on the land throughout the process of urbanization, the inertia of the territorial condition where São Paulo stands on a várzea exerts forces on the sprawling metropolis. Várzea is the Portuguese term indicating lowland areas bordering main rivers and their tributaries that are subjected to flooding. The closest translation in English is “floodplain”. Annual Inundation brings in resources and enriches the soil. Since the alluvial soil is highly impermeable, floodwater during monsoon season expands drastically at the ground level. Nevertheless, adjacent to the várzea are the hills of the Piratininga Plateau. The upland area became home of Tupinikim people who built villages that are considered to be the origin of São Paulo. The unique topographic relationship between várzea and hills and their subsurface condition foster formation of numerous natural springs at the peripheral of watersheds. Towards the north region of São Paulo where the edge of urban settlement meets forest, natural springs are less endangered since they are sheltered by dense vegetation. Springs in São Paulo are capillaries feeding larger river veins. They are important habitats for pioneer fish fry, insect larvae and amphibians. They also have abilities to process nutrients, dissipate energy, process sediment, and maintain stream energy dynamics to support downstream ecology. However, because natural springs are small and sometimes seasonal so they are often neglected due to low economic status and lack of information.
“Natural spring found in the Itakupe Village” Jaraguá, São Paulo Photograph courtesy Existe água em SP Soil Map of São Paulo
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(Nov, 2015)
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If one talks to paulistanos, spring is no surprise to many of them who have had springs in their backyards for generations. Some families use pipes to direct the water or store it in buckets for daily use such as cleaning floors and watering plants. But most of the spring water, some of which runs at a rate of as much as 5,000 litres per hour with good quality, makes its existence in street gutters gushing down to drainage or mixed with sewage before finding its way into the river Pinheiros and the river TietĂŞ (Rigby, 2015).
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URBAN SPRINGS IN SÃO PAULO
"We came here in '78 but this spring had existed for many years, The spring never had a water problem. It always gave the same amount of water. And people come to pick it up from here. When the crisis sets in, we won't have water for two, three days in a row. People line up with barrels and buckets, so we can supply water to them. We have to keep the water clean, and always keep on cleaning and caring for it, understand? Otherwise future generations will suffer in the future, they really will suffer."
Interview of a São Paulo local on the spring in his backyard after water crisis "The Dramatic Power Struggle Behind Impeachment in Brazil" Video courtesy to TIME (2015)
“A nascente sprout on the street”, Photograph courtesy Existe água em SP Penha, São Paulo (Nov 2016)
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SPRING DISCOVERY: WATER INITIATIVES AS A CULTURAL PRACTICE
EXISTE ÁGUA EM SP WATER EXISTS IN SP
CIDADE AZUL BLUE CITY
MOSTRA RIOS E RUAS RIVERS AND STREETS INITIATIVE
HEZBOLAGO
Nowadays, multiple water initiatives emerged in São Paulo and has made public impacts regarding calling people’s awareness of the hidden springs and rivers in the city. On this issue, Rios e Ruas is the largest one that has branches in multiple cities of Brazil. The organization actively works with other non-profits and local experts to push documentation of the hidden rivers and streams, engage public through water expedition, art installation and culture events. Rios e Ruas was created by Instituto Harmonia in 2010 as a result of the partnership of the architect and urbanist José Bueno with the educator Luiz de Campos Jr. Their project offers the recognition of the main hydrographic basins of São Paulo and the exploration in locale of the rivers and streams of the city with the idea to prompt design with a more distributed approach.
One creation of Rios e Ruas is the Blue City Mission, a transmedia project that combines audiovisual narratives with a mobile game. The game will be based on geolocation and uses the augmented reality tool. Blue City Mission relies on ancestral cultures and traditions to create a narrative of reconnection with nature in cities, with a guiding line for the rescue of polluted and marginalized rivers. "There's a river in the middle of the road" Image courtesy Rio e Ruas (2013)
“Pond filled with water from the surrounding condominium made by the initiative Secura Humana” Vila Pompeia, Sao Paulo Photograph courtesy Existe água em SP (Feb, 2018)
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THEORY | TOWARDS ATOMIC URBANISM
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CRITICISM OF MODERN PLANNING
"The Cebolão, confluence of the Tietê and Pinheiros rivers" São Paulo, Gooogle aerial and ground photo looking east courtesy Daniel Pascoal
Through investigating into urban nascentes and headwaters that concern interventions at local scale, one objective of the research is to develop a position with specific example and tools to challenge the conventional paradigm of urban planning that has deep roots in its modern tradition. A great number of megacities in the world are located within coastal or riverine systems through which these cities bred culture and accumulated wealth. However, with improvement of productivity and liberation of labor during industrialization, roads and buildings became the driven factors in planning as cities grew. In the age of Anthropocene, streams and waterbodies that constitute landscape are rarely considered to have its own rights to exist unless they are tailored to favor the constructed systems and urban structures. A classic example is the 1971 L’Enfant Plan of Washington D.C., the elements of which bespeak the style of modern planning as a systematic, top-down line-laying activity over the earth with a logic of geometry. In this case, the edge of the Potomac River and its flow have to conform to the lines drawn by the planner and eventually became ports and canals. The spatial indications of planning as such in the city of São Paulo are best exemplified by the Cebolão, the confluence of the Tietê and Pinheiros rivers where massive infrastructure of transportation, sanitation and flood management are intertwined, isolating the rivers with the rest of the city as well as its people.
The L 'Enfant Plan (1971) of Washington D.C., United States Garden History of Dumbarton Oaks
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COMTEMPORARY PARADIGM: GREEN INFRASTRUCTURE
A contemporary remediation in response to results of modern planning is the application of green infrastructure. According to USEPA (United States Environmental Protection Agency), Green infrastructure is a “cost-effective, resilient approach to managing wet weather impacts that provides many community benefits”. While EU defines it as “a strategically planned network of high quality natural and semi-natural areas with other environmental features, which is designed and managed to deliver a wide range of ecosystem services and protect biodiversity in both rural and urban settings” (2013). As broad as it could be, the term “green infrastructure” is a general concept that implies environmental-friendly addendums complying with the existing systems of urban layout. However, focusing on environmental performances, green infrastructure exerts little on social and cultural transformations.
Trent Street Rain Garden, a local project in Victoria British Columbia, Canada Photo courtesy Murdoch de Greeff Inc
Water Square Benthemplein, multifunctional detention ponds in Rotterdam, NL Photographed by Ossip van Duivenbode, courtesy Centre de Cultura Contemporània de Barcelona
For instance, green infrastructure is not applicable when discussing Dutch water management practice though function of many dykes in urban areas is green infrastructural. With millions of dykes and ditches to manage water in both urban and rural areas throughout the nation, the word “green infrastructure” fails to afford Dutch mentality to live with water or to reflect the integrity of various water management projects in the Netherlands. The key difference in the Dutch case is that they lay out waterways first and build towns and cities accordingly in response to the physical conditions of the land; whereas in most other cases of urbanization throughout modernity, people lay out streets and buildings first and then they drain water away from cities. Although contemporary urban developments have been taking an environmental turn through use of green infrastructure, the fundamental relationship between urban dwellers and water systems and the culture of treating water remain unchanged. Is it possible to integrate the mentality of prioritizing water as the main drive for design while re-examining the ground and urban condition of São Paulo? Although green infrastructure, especially installations of rain gardens and bio-swales may seem a sophisticated practice elsewhere in the world, these strategies may not apply to São Paulo due to drastic differences of natural environment, urban structures as well as dynamic social and cultural contexts. In particular, systematic approaches often prove to be ineffective in Brazil as the result of constant change in political climate. In this case, instead of using green infrastructure, the research looks into the idea of nascente to search for more localized approaches.
Vila Aurora, Estaçã, São Paulo Photograph courtesy Existe água em SP (Feb, 2017)
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ATOMIC URBANISM
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Punctuational Intervention
Systematic Intervention
SCALE DIFFERENCE Watershed is a concept applicable at regional scale while a spring catchment area could be referred at the scale of a building block. Sporadic/random
Extensive/planned
FLOW DISTANCE
1st contact with ground
Collection of collections
The distance of flow into an immediate catchment area is much shorter so they tend to carry less contaminants.
IMPACT AFFORDANCE Spring catchment areas are vulnerable to constant changes of urban environment. Dynamic change
Stable surface condition
IMPACTFUL SURFACES
Verticle impacts
Horizontal impacts
Spring catchment areas are more responsive to vertical aspect of impervious surfaces, i.e. building facades and walls.
While planning systematically may fail in the context São Paulo, atomic urbanism is a view in the direction of anti-planning. Deviating from system-oriented planning practice that is often top-down and panoramic, this research proposes an acupunctural approach that allows randomness and plasticity as a way of organizing urban space in a comparatively chaotic social context. Contemporary urban settlement and development of São Paulo that prioritize construction of infrastructure and building left no mercy for springs and rivers. Particular in the case of recovering springs in São Paulo, lack of information and governmental attention has posted enormous challenges for to build projects at larger scale. Therefore, the idea of atomic urbanism is to shift the paradigm of system thinking in conventional planning practice so as to target individual cases at strategic locations for interventions at local scale. 29
NASCENTES: BASIC UNIT OF ATOMIC URBANISM
The emergence of water is celebrated across cultures. In Rome, ancient architects redesign grotto with natural springs into a nymphaeum, a monumental space dedicated to nymphs - a deity identified with life-giving outflow of springs in Latin mythology. Similarly, commemoration of spring also exists in Brazilian context in a more modest fashion. "Nascente", literally meaning the place where water emerges from the ground, is the pond formed with springwater. The concept of nascente is utilized in this design research to establish cultural meanings as well as produce momentums to reconstruct urban headwaters, which engenders a different approach to stormwater management by creating a cultural landscape. Pinheiros River
2. HEADSTEAM Headstream is the path giving the main expression of headwater. It tends to form and reinforce the path in areas with continuous, linear depression.
Removel of urban surface to unveal the spring source
3. VEGETATION
1. NASCENTE Headwater could sustain water flow for at least a season because they are connected to a waterbody at a certain size.
Headwater are often surrounded by vegetations as it provides easier environment for seed to germinate and grow. Constructed area to hoard ground/underground water and discharge slowly
To consider nascente as the basic unit of atomic urbanism, the research concerns the beginning moment of water on a formal map that is commonly used by planners and regards the point as the strategic location for design. In the case of São Paulo, the beginning of a stream is manifested by actual spring but in reality, condition of spring is drastically altered by urban development. Thus through removal of ground surface and constructing ponds to delay draining activities, the capillary of hydrology could be potentially recovered in the urban setting.
Nascente near Rio Água Preta Vila Romana, São Paulo Photograph courtesy Existe água em SP (Oct, 2016)
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EMERGENCE OF WATER Spring as a water type and a natural phenomenon depicts the essence of water emergence and is the ideal location for building nascentes. Geologically speaking, spring is a result of groundwater overflowing onto the land surface. The groundwater could rise from aquifer recharge or water accumulated on top of an aquiclude – an impermeable body of rock or stratum of sediment under the ground surfaces at any elevation. The process involves rainwater infiltration, underground material saturation, and groundwater accumulation until enough volume of water pressures through cracks and leaks out. The section below illustrates the soil profile of JaguarÊ Basin and speculates the process of spring burst-out.
Primary rock aquiclude
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Underground water layer
Spring burst-out as both topography and soil type change
Terciary sediment allows percolation
The Jaguaré Basin is located in the western part of the Municipality of São Paulo, corresponding to 1.9% of the total area of the Municipality. The River Jaguaré is born near the border of the municipalities of São Paulo and Taboão da Serra. After confluence with River Itaim, runs along Avenida Escola Politécnica. Some spring sources are marked on the basin soil map while others are speculated based on change of soil types and topography.
Watershed Area= 28.2km² Total River Length = 90km Population (2020) = 272,454
Escorregamento
Compacted urban soil
Alluvial/Clay
Primary Rock Terciary Sediments Alluvial Spring (known) Spring (speculated)
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“Spring water fed into runoff supporting growth of vegetation”, Screenshot from video "Rio Verde" by Cidade Azul, (2016)
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MATTER OF SCALE IN URBAN SETTING
Urban settings complicate the environment for the formation of springs as well as its discharge pattern. Clarification of scale is essential here to structure the study and its urban implications. The research parallels units of urban fabric to the similar-scale of ecosystems, which in the meantime indicates the size and typology of waterways associated with the environment at the pertinent scale. In this regard, spring is situated within the scale range between a drop of water and the size of a primary stream in both natural and urban environment. This primary limit of scale provides feasibility for measurements of spring especially in urban environment.
DRAINAGE/STREAM TRIBUTARY
DIRSTRICT
PATCH CLUSTERS
SPRING/RUNOFF MIX
NEIGHBORHOOD
FOREST PATCH
PIPE/SPRING DISCHARGE
HOUSEHOLD COMPLEX
CANOPY
A DROP OF RAIN
PAVER TILE
LEAF
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METHODOLOGY | WHERE WATER IS PRESENT
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THE SITE : JARDIM BOA VISTA
1930 map of Jardim Boa Vista Mapa Digital da Cidade de São Paulo Prefeitura de São Paulo Historical contours indicate three stream valleys existed within the region of Jardim Boa Vista that fed the river Itahim. The head of the stream valley were covered and protected by forests.
JAGUARÉ WATERSHED 1,521 km2
JAGUARÉ WATERSHED 29.4 km2
Although speculation of urban spring is illustrated earlier, the form and presence of urban spring is still vague. In this case, the research utilizes both deductive and inductive reasoning to probe the issue and situate the design of urban nascente in a specific site – Jardim Boa Vista, a neighborhood located towards the west of the São Paulo city and in the upper portion of the Jaguaré watershed. Centered in the specific location, this chapter combines observations from street view of Google Earth Pro, sonic analysis of the site digital model and synthesis of field research to analyze urban springs in São Paulo.
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JARDIM BOA VISTA 1.6 km2
Tributary 03
Tributary 02
Tributary 01
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"Spring treated as runoff", Sumaré, São Paulo Photograph courtesy Existe água em SP (Dec, 2014)
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URBAN CONDITION: MIXTURE OF SPRING AND RUNOFF
Diverge Separating into different direction from a main route.
Spring water are treated the same as surface runoff. All water is mixed and collected by gutters and then drained away. There are several ways that urban surface carries waterflow. A nascente in this condition is to catch flow as close to origin points as possible to reveal the presence of water.
Coverge Coming from different difrections and meet at a place.
Aboveground: elevation map of the site High elevation Medium elevation Low elevation Point where surface flows converge
Redirect Direct to a new or different place or purpose.
Spring burst-out points could have existed within the boundary of the site based on change of soil types and topography. Locations are indicated on the soil map
Drain To cause the gradual disappearance of water.
Underground: soil map of the site Primary Rock Terciary Sediments Alluvial Spring (speculated)
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STREETVIEW EVIDENCES
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Drains
Discharge point
Streetview of Google Earth Pro is the first-hand tool to immediately engage with the site context especially under the circumstance of lacking formal data. I took multiple “virtual walks� through the neighborhood and developed a route and noted questions as preparation for the future site visit. In the meantime, I marked drains and different types of discharge point (domestic, semi-public and public) and road cracks in the neighborhood. These devices are telling regarding appearance and disappearance of water in this region.
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ANALYSIS OF URBAN FLOW
01 | Surface Rebuilding
Terrain surface
Elevation Zones
Contour of terrain only
Terrain + building surface
Elevation Zones with buildings
Contour of terrain + buildings
Speculatively, another possible depiction of urban spring in this case could be the pattern of surface flow following topography and building footprint because regardless the emerging point of spring, its flow would be dictated by condition aboveground in urban settings. To simulate surface flow, I built digital site model, integrating building surfaces into the terrain surfaces to reach a more comprehensive flow pattern with consideration of building footprints. More specifically, the model uses Rhino 3D and its plug-in Grasshopper to first build the terrain mesh, then extrude the building footprints with height information collected from Mapa Digital da Cidade (MDC). The next step is to project the extruded buildings onto the terrain, clean up the model and join the meshes so the building surface become part of the terrain.
02 | Populate Initial Points to simulate raindrops
The altered surface is the ground for the simulation. Random points are populated and dropped on the terrain to simulate flow. The process of dropping random points could be repeated multiple times to improve the liability of the result.
Populate random points and project them onto the surface
03 | Sphere cut plane to find next lowest point
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Analyze the flow direction of each initial point
The logic of the simulation with the Grasshopper script lies within a loop of “finding the lowest point”. In other words, each dropped point, or to say, the “raindrop” on the surface is turned into a mini sphere that cuts the surface with a circle. The script calculates the lowest point on the circle that is the location the “raindrop” moves towards. Simultaneously, information of the lowest point is fed back into the loop as the input for the next run. As a result, the drop always finds the lowest point within a small zone that approximately captures the behavior of water movement.
Parameters Sphere Radius:10cm Loop Iteration:80 Raindrops: 300
10s
30s
20s
50s
30s
60s
70s
simulation result with only terrain as the input surface
Parameters Sphere Radius:20cm Loop Iteration:150 Raindrops: 300
10s
40s
20s
50s
30s
60s
70s
simulation result with building and terrain as the input surface
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ANALYSIS OF URBAN SURFACE : RAIN DROP SIMULATION WITH FOCUSED AREA
Populate 1
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Populate 2
Populate 3
Composite
pr=2
pr=5
pr=77
Tributary No.1 Trellis drainage pattern
pr=77
pr=67
pr=59
Tributary No.2 Contorted Discharge Pattern
pr=59
pr=42
pr=13
Tributary No.3 Dendritic Discharge Pattern
Parameters Sphere Radius:2cm Loop Iteration:150 Raindrops: 100 Populate randomness: pr
To reach the best result of the flow simulation, the number of population points (raindrops) is limited within 300 for each run of the script. At the scale of the entire site, the resolution of generated flow pattern does not capture specifics of some interested areas. In this set of graphics, I applied the simulation script separately to three focused areas so each area received more random points and gave more informative flow pattern. Estimated from topography, each focused area approximates the catchment area of the buried rivers on existing map. The main purpose of this study is to draw a picture of surface flow that feed into the path of each buried river. Throughout the study process, I changed the factor influencing the populating pattern of the "raindrop" points for three times in this case, and overlaid the results to reach a composite drawing on the far right row. Ideally, the process could be repeated as many times as it could be to attain accuracy. But supreme accuracy is not the particular concern in this set of study; instead, a formal indication of patterns is the goal.
Interestingly, each of the three interested tributaries present different flow pattern reading the results of the simulation. The tributary No.1 has a trellis drainage pattern, which speaks to the regular two-row buildings layout in its studied zone. The tributary No.2 has a broken contorted discharge pattern that speaks to the irregular building layout in response to sudden topographic change. Nevertheless, an area with agglomeration of points emerges. A favela settles in this area and surrounding water are all collected into the favela. The tributary No.3 has a dendritic discharge pattern that indicates its catchment zone is relatively less impacted by human activities.
Flow pattern of terrain overlaid with paths of the buried rivers, indicating linear depressions that are potential paths of headstreams.
While the method captures certain aspects of urban structure influencing water flows in the Jardim Boa Vista neighborhood, limitations remain to this approach. Stormwater infrastructure is not taken into account in this set of the study. Structure of factors impacting water flow
CONTAINER ROOF
PIPE DRAIN WALL STAIR
DOMESTIC DISCHARGE Building facade surface runoff
THRESHOLD
RAIN EVENT GROUND RUNOFF
STREETS
Highways and streets are mostly impervious
STAIR GUTTER DRAIN
CHANELLIZED STREAM Many streams are not separated from sewage
DOMESTIC DISCHARGE Indoor outlets of grey water
PIPE
Flow pattern impacted by building surfaces, giving zones of wash-prone areas, overlaid with paths of the buried rivers.
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FIELD WORK OBSERVATION I went on a site visit for two days and I noticed that the topography changes dramatically with several steep streets. Some streets are intensively used by cars especially those on the bus transit routes. Because of the slope, each household makes their own steps at the doorway to keep level even, which overtake the pedestrian space leaving it unwalkable. There are two community parks commissioned by the local government. However, the space is mainly used by the elders and local drug dealers. Young people only transit through the parks instead of using it. Unspoken rule seems to be played regarding the usage of public space here. Some elders sat at their front doors to bath sunlight. It is worth to notice the community has five schools (ranging from kindergarten to collage), three churches and a health care center. These institutions suggest demographics and culture of the neighborhood.
Local Educational Institutions: Roberto Arantes Lanhos Nursery Municipal School of Children's Education Deputy Gilberto Chaves Solano Trindade Municipal School of Fundamental Education State School Professor Oswaldo Walder Waldorf Micael College
Green private space Future real rstate development (Fenced)
Favela Community park School Community park School
Tributary No.1 550m
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Tributary No.2 500m
Tributary No.3 700m
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FIELD WORK: DEFINING STRATEGIC LOCATION
HP | Tributary No.2 11:10am Favela is hardly seen or accessible by strangers but is located at drop of topography.
HP | Community Park 10:40am The park is designated for old people in the neighborhood but it also became the spot for drug dealers.
HP | Tributary No.1 10:20am The large, paved intersection where water converges and begins to flow down into the school is also the trash collection spot
LP | Tributary No.2 11:30am Where water flow out of the favela as a stream that collectes a lot of domestic trash.
LP | Itaim River 11:50am Sewage is diacharged in to the river. School teacher blamed monsquitos from the river. There is an informal shed (a bar) constructed on the bank.
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Headzone of Tributary No.1
Stream 03/15 Trail
Headzone of Tributary No.2
03/16 Trail
Headzone of Tributary No.3
There was no actual spring observed on streets but signs of constant waterflow with vegetation were identified in some areas near the head zone of Tributary No.1. Multiple drains were installed to discharge surface water while the entire Tributary No.1 was buried underground. Its head zone is paved over by streets, and then it goes under a school and a health center. Space of these two institutions is walled off so the stream is unseen. 51
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DESIGN | WATER AS FIGURE
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INTERVENTION LOCATION
Traffic Diagram
Flow Diagram
Single traffic Discharge flow Blue zones Household traffic Spatial Arrangement
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The initial idea is to transform the intersection that used to be a trash collection point into an attractive node with design of a nascente as a spring catchment area to celebrate beginning of water. To make it a public space, inspiration is drawn from Noguchi's garden to make the nascente a sunken plaza with pools. In addition, pervious paving are integrated while more trees are planted to reclaim the street from the traffic. Drains in the area are redesigned to direct street runoff into the nascente. The roof at the school on site could also be utilized to collect rainwater. Isamu Noguchi Chase Manhattan Tower Plaza Sunken Garden, NYC Photo courtesy Ty Law via Flickr (2017)
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A'
D
B'
A
C'
R D . R O
B
S E LA C O M B E
STATE SCHOOL PROFESSOR OSWALDO WALDER C
RD A AR .S
D'
NE W TO N
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NASCENTE MASTER PLAN AND SECTIONS
A
A'
The width of street is cut into half and reclaimed by pervious paving, allowing household car to enter their own parking in the yard while creating a green public playground for kids in the neighborhood. More trees are planted for shading and attraction.
B
B'
A vegetation barrier is designed to filter the nascente overflow during monsoon season and direct clean water to the meander waterway dug in the schoolyard.
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C
C'
Roof of the playground shelter are redesigned to collect rainwater and feed the nascente. The roof also calls visual attention of pedestrians as a sign of entering public space. One street is transformed in to a single-traffic lane.
D
D'
The mixed water collected in the nascente would sit in the pools and rise. The pool water is treated by the vegetation and cleaned overflow is discharged back into the waterway that is dug in the schoolyard.
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INFILTRATION AND FLOW DIAGRAM
Bio-Swale
Aquatic Plants
Sunken Plaza Collection Pool
Vegetation Buffer
Roof Drain
Pervious Paving
Daylighted River Channel
Vegetative Infiltration Diagram
Flow Diagram
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MONUMENTALITY OF POOLS
Through act of cuts and fills, clay, 2018
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Paper model testing the flipping angle of the new roof for the playground shelter in the school, inspired by banana leaf
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MONSOON SEASON VIEW
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HYDROPOGICAL FUNCTION
E
F'
F
E'
The plaza space with the pools is meant to accommodate flow volume of both monsoon and dry seasons. During the monsoon season the sunken plaza will function as pools to accommodate street flood flash. The overflow will be filtered by a vegetation buffer and directed to a meander river channel that is designated to recover the stream path. During the dry season, the pools will collect mixed spring runoff to hold constant water. With planted aquatic plants, the water would be treated for overflow discharge during monsoon seasons.
2016-2017 São Paulo Rainfall Data Source: World Weather Online
E'
E POOL METRICS THE 1ST POOL: 8 m³ THE 2ND POOL: 65 m³ SUNKEN PLAZA: 28 m³
Monsoon seasons water level and overflow refilling daylighted stream
POOL METRICS v THE 1ST POOL: 8 m³ THE 2ND POOL: 65 m³ PLANTS PLATFORM: 28 m³
F'
F Constant water level within the pool
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ECOLOGICAL AND SOCIAL FUNCTION
Masked Water-tyrant
Cattle Tyrant
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Fat Tilapia
Peixe Cascudo
Amur Carp
Paulistinha
Crucian Carp
Espadinha
Common Carp
Tiny GuarĂş
Brazilian Sword
Cabomba
Water Sprite
Amazon Sword
Micro Sword
Java Fern
With constant base water level in the pool, bird species such as Masked Water-tyrant and Cattle Tyrant tend to be attracted to feed on insects. Fish species are introduced to eat mosquitos and their larvae. Carps with bright color are also fostered for visual enjoyment. Varying bottom of the pool allows containments to deposit and contained while cleaner water will flow through the vegetated portion of the pool.
DRY SEASON VIEW
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NACENTES AS MEANS OF ORGANIZING URBAN FABRIC
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Cutting a cross section of the lower valley where tributary 01 was drawn on the map, the drawing suggests that multiple nascentes could be installed along the path of the Tributary 01 to collect, slow down and clean the spring runoff mixture and potentially daylight the tributary. They could also perform different cultural and social functions in the private properties of public entities. Within local school, a nascente could be educational and within a health center, a nascente could be therapeutic. A nascente could also be a central feature of a garden within people's backyard. Essentially, a nascente gives presence of water in a formal way that calls people's attention and care. As an urban hydrological unit, it would also potentially impact urban footprint of its surroundings by claiming public space.
Change of water speed along the cross section of the tributary 01, showing the hydrological connecetion to the Itaim River
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CONCLUSION / URBAN IMPLICATION Through design a nascente at a strategic location in Jardim Boa Vista, the intervention reveals social, cultural and environmental implications. Unlike a bio-swale that mainly functions as a detention pond that is designated to treat runoff, a nascente essentially gives meanings to the spring water flowing into the pool by reclaiming part of the street intersection and forming public space. The space would invite local residences to meet at the point to recognize and celebrate the water with an awareness of the pool as the beginning point a stream. The design of the pools within the nascente provides an environment for aquatic plants and fishes to establish a niche to treat the water and feed the cleaned overflow back to a day-lighted river. Beside local people, the space would attract birds and other urban wildlife. More importantly, the act of celebrating water by means of nascente on a street pushes changes of its surrounding households. Rooftops nearby could be redesigned to collect more rainwater to feed the pool, other portion of streets could be reclaimed for pedestrian use to enter the space of the nascente. In other words, nascentes is a cultural node that would engender transformation of the neighborhood. The presence of water in the form of nascentes also suggests what urban headwater could be like in SĂŁo Paulo since surface flow in the city are often mixed with natural spring water. Headwater in urban settings is much more dynamic and fragile than a channelized steady stream. And they are less systematic with its pattern and condition. To recreate and manage a lower-class hydrological unit through local efforts, a nascente network could present itself as a series of acupunctural catchment pools that may or may not connected by waterways to feed regular high-order streams as well as shape local public space that conveys the idea of atomic urbanism. Also in the case of Jardim Boa Vista, it is more realistic to work with local schools and health center to propose several nascentes as pilot projects to facilitate future actions of uncovering other buried streams in the neighborhood. At local scale, this atomic approach considers changing condition of the land with dense urban settlement and structure. It is thus more promising for its flexibility and cost-efficiency to reshape the relationship between water and people on the daily basis.
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WORK CITED Davies, R. (Mar 23, 2015). Heavy rain floods Sao Paulo again but drought persists. Floodlist. Retreived from http://floodlist. com/america/heavy-rain-floods-sao-paulo-drought-persists. Davis, B., & Jensen. A. (2015). River Landscapes of São Paulo: Várzeas and Piscinões. In J. Beardsley (Ed.) & T. Way (Eds), River Cities, Historical and Contemporary (pp.217-241). Washington D.C.: Dumbarton Oaks. Freitas, G.K. (2011). São Paulo secretariat of environment, Brazil. In J. Cook (Ed.) & S. Freeman (Eds.), Shifting course: Climate Adaptation for water management institutions (p.56-61). Washington D.C.: WWF. Hough,M (1995). Cities and natural process. London: Routledge. Kevin W. K, Peter C. S. JR. & Norman R. F. (2009). Hydrology of channelized and natural headwater streams / Hydrologie de cours d'eau recalibréset naturels de tête de bassin, Hydrological Sciences Journal, 54:5, 929-948, DOI: 10.1623/ hysj.54.5.929. King, W.K., Smiley, Jr. P.C., & Fausey, N.R. (2009). Hydrology of channelized and natural headwater streams: Hydrology of recalibrated and natural headwater streams. Hydrological Sciences Journal, 54(5), pp. 929-948. OEPA. Ohio primary headwater habitat streams. Retrieved from http://www.epa.state.oh.us/dsw/wqs/headwaters/index. aspx#123356693-project-reports--field-evaluation-methods Prefeitura de São Paulo. Mapa digital da Cidade de São Paulo: Zona Azul. Retrieved from http://geosampa.prefeitura.sp.gov. br/PaginasPublicas/_SBC.aspx. Rigby, C. (2015, Mar 11). “The river hunter of São Paulo: a life devoted to finding its lost waterways”. The Guardian. Retrieved from https://www.theguardian.com/cities/2015/mar/11/river-hunter-sao-paulo-lost-waterways-failing-megacity. The World Bank (2012). Integrated urban water management: Case study São Paulo. Washington D.C.: The World Bank. UN-Habitat (2010). São Paulo: a tale of two cities. Washington D.C.:UN-Habitat. University of New Hampshire Cooperative Extension (UNHCE, 2018, January 26). Headwater streams. Retrieved from https://extension.unh.edu/resource/headwater-streams.
DATA AND IMAGE SOURCE Special accredition to Mapa Digital da Cidade (MDC) for providing all the raw data and Existe água em SP for share local spring and nascente photos on its main website.
Nascente Rio Saracura Consolacao, São Paulo Photo courtesy Arie Storch (Apr, 2017)
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