Latin Pratt is putting on a large and impressive exhibition titled, “Breaking Borders”, in the Robert and Hazel Siegel Gallery in New York. U-TT’s work will be featured along with over a dozen other firms’ projects. Definitely stop by between Sept. 8th and November 30th. More details on the Breaking Borders website.
Boulevard da Paz is a site with extreme changes in topography, located on the outskirts of southern Sao Paulo city. The area lacks nearby employment opportunities and has problems with physical access along steep slopes. Water control is also an important issue as stormwater creates the risk of landslides.
I hope to use Boulevard da Paz’s topography to its advantage – creating an economically and environmentally productive space for the favela residents. I am proposing the introduction of agricultural terracing along steep valleys that are currently unusable – growing high value crops to generate income and create jobs, reinforcing the slopes to prevent landslides and using gravity to treat agricultural and urban wastewater runoff.
Efforts from the government has been made to develop housing programs to provide improved living conditions and right to hous
ing for the families here in São Francisco for decades. However, the process of replacing people into the new vertical dwellings creates problems like gentrification and residents unable to pay for the development and therefore, stay, in their new homes. Also, the lives of residents could hardly be improved by solely providing living spaces; the lack of commercial and public spaces still renders the area a bleak urban landscape. Moreover, the construction of new highway, Jacu-Pessego, right through São Francisco will bring tremendous impact to the existing communities.
1. Access – confined by traintracks on all sides, there is only one point of access. 2. utilies – only one water connection for entire favela, illegal electricity and illegal sewage that ends up in rivers 3. sanitation is very poor – piles of garbage, stagnant water and sewage runoff 4. nearby is an area notirious for all-day drug use, violence, etc.
As you can see in the site plan above, there is a lot of old industry and service surrounding the site… a lot of old dilapidated buildings. there is just not enough residence in the area to promote a healthy social situation, and the drug users took over. but this area is so close to downtown Sao Paulo, that it can really be somthing special…. something new and exciting for the entire city that will revitalize the area and bring businesses and people in the following years… the conditions in the favela are really just too poor to keep the favela there, but it is important that housing is first created just on the border of the site, so that the faveladores have a new home nearby before the favela is removed….
the basic idea is to cover the train tracks, the train yard, and the mill with a series of roof systems… this will provide program space on top of and below this roof system…
below is a conceptual site plan for intervention…
above you see the room system (some of which is covered in linear park, which is green), and then layered on top of the roof system are different programs – some cafes, galleries, some shops, some athletic facilities – so that we start to have an extremely active site, mixed with open areas full of grasses and trees, with beautiful views looking out to the rest of Sao Paulo…
the roof system will tie into existing buildings of the site and next to the site and will make connections to the rest of the city via ramps, stairs, platforms, elevators, cable cars, and more…
so the next question is what will the units of program look like…
a kit of prefabircated parts will allow for simple construction of a variety of complex shapes… the above image is only one example….
above is the aggregation of these program components, and the roof system will weave these elements together.
the above rendering is not the greatest rendering, but it gives my first overall idea of the system… but i intend for the design to be less massive than this, less solid… it will be segmented more and there will be more cuts into the roof to get light down below, and of course much of the roof will be covered with green grasses and trees and people… program space is on top of and beneath the roof…
Cocaia and Nova Grajau within the Billings Reservoir System
A prototype of ecological housing and land remediation on a local scale in Cocaia + Nova Grajau is an example for other sites on the Billings Reservoir. It restores the water quality of the entire reservoir through 3 local stages of natural remediation, while redirecting floods + storm runoff through street trails, housing tiers + reservoir burm islands. Incorporating new housing, recreation and wetlands, this site is an integrated network of improved living and leisure.
Parque Sao Domingos is essentially an island favela surrounded by middle-class housing. There are 669 inhabitants living in a fairly small plot of land. The site has a unique condition of having a large soccer field as well as a sports court that have been religiously not invaded. The two main issues of the site are: a) all the houses bordering the street to the southeast have been built over a stormwater canal and are in danger of collapsing and b) the site is very dense and unhealthy in areas. The proposal currently is to do an “acupuncture removal” to de-densify and allow room to go down and repair the water canal. These open spacescan have leisure activities inside the favela, or the spaces on the edges can become programmed areas that are currently lacking in the site. A community center and new housing can be built over the existing sports court and the soccer field can be re-dimensioned and rearranged to allow for more program around or even underneath.
Proposal: Youth social network driven by cultural events. Through a social network which provides dutch-morrocan youth cultural events, they socialize among those with the same interest and find themselves in the society. Variety of dutch-morrocan youth prefered cultural events are held in multiple locations in all over Hoograven. Each time a different event takes place in one of many event locations and other networked event areas direct the scattered youth to the event location. All the locations are public that is exposed to the neighborhood. As what a little camera does to Kibera youth community and the culture, this network is a motivation for dutch-morrocan youth to what they can cause for their own cultural standing in the community and to find themselves in Dutch society.
Programs proposed: cultural obsession is a good vehicle to transfer the youth enthusiasm toward finding social identity of their own. Skateboard parks, Video graffiti walls, concert stages, and all include information interface integrated to the programs that direct the youth to the event. All the proposed programs are linked to existing local youth programs in an effort for cultural boost of the community.
1. informal economies: Slum dwellers have little or no access to formal sector jobs. The informal economy fills the gap left by the formal economy, as it fails to manage the growing population of the urban poor.
2. informal space: Economic exclusion leaves slum dwellers with no access to formal property or space. Space is created and adapted individually and organically to meet individual economic and social needs.
Possible application in Utrecht: Moroccan immigrants, like slum dwellers of the developing world, are excluded from western capitalist society. Informal concepts can be applied to fill this gap, at the economic and spatial levels. Design and policy can work together to address this issue.
Policy proposal: 1.a property ownership program; reconfiguration of the welfare state: -Generate capital for immigrant population. -Reconfigure long-term investments in unemployment and income support to short-term investments in construction -Long-term municipal gain through property taxes, implemented with a 20-year abatement plan
1.b small capital enterprise program -entrepraneurship program to encourage marginal and small enterprise -training programs
Design proposal: 2.a design your own home and business -input from occupants should be encouraged to better satisfy individual needs -can parametrics create an interface to mediate between input (design criteria-family size, lifestyle etc) and ouput (financial loss/gain, form)
Generally, the urban redevelopment costs huge money. There are construction costs, real estate, marketing costs and etc. It means that somebody should pay for that money, because developers want to collect the money that they invested.
Thus, developers shows interest the slum areas which are low real estate cost but high value for development in the city. They want to make a profit as much as they can. They gives money to something which can be marketable. Usually, marketable means two things. Space and program.
General redevelopment of slum area shows high density and vertical buildings, or luxury office or housing. In both cases, existing tenants or neighborhood lose their original characters. My question is “Is it possible to keep or intensify original character of neighborhood and tenants after the redevelopment in the view of marketability.
The re-development of established living environments, where a community has been able to grow, will always involve a degree of exclusion and displacement. The questions you ask in this proposal are of extreme importance as we enter a new era in the global urban landscape. 1 billion human beings live in ‘slums’ around the world and this number continues to grow every day. The interaction between developers and these areas of extreme poverty have become an issue of human rights. In many places in the world the major development firms are either owned by the state or have a close relationship with the military and police force. In this way they are able to force people from their homes through violence, extortion, or by simply demolishing their homes without warning.
If Neil Smith is correct in his assertion that “as the neoliberal state becomes a consummate agent of—rather than a regulator of—the market, the new revanchist urbanism that replaces liberal urban policy in cities of the advanced capitalist world increasingly expresses the impulses of capitalist production rather than social reproduction”, then the protections offered by the commons to those individuals who own no property, the homeless, the displaced, or the migrant worker, will face increasing exclusion from the public land on which they are forced to live (Smith 2002, 80).
We are witnessing the largest migration of people the world has ever seen. The question of how we develop new living situations lies at the crux of problem. How can the neoliberal capitalism of the 21st century act as both the instigator and solution? Can design alone serve as the conduit through which reparations can be made? I think it can. But idealism is not enough, it takes hard work and a clear agenda to solve social problems. The architect must also be of the people, we cannot be vanguards, we must listen to the voices of the multitude. The ‘concept’ of modern architecture must evolve. We need to realize that the simple precepts of mass production, consumption, and exploitation no longer function. What needs to be marketable is human dignity, human community, and social justice. This will never be achieved by building luxury condo on what was once a thriving low-income community.
The usual approach to develop of this kind is a system of multi-use—multi-function buildings. Thus creating a kind of artificial social hierarchy while leaving room for all kinds of lifestyle. The problem with this is that the higher priced programs get privileged because they make more money for the developer. How can you design a system of housing that is both appealing to high class tastes while maintaining a low cost for low income tenants? Try to build bridges between classes instead of erecting barriers. Think of the marketability of appealing to all classes simultaneously. Think of a space for the “global citizen”, a program for a “border-less world”.
The open network of ramps/walkways/bridges aim to accomplish: improve wayfinding and circulation within Paraisopolis to its periphery, contain programmatic elements, generate and distribute energy. I began developing a grain diagram of Paraisopolis that defines the negative spaces/existing corridors that these walkways can plug into – so rather than being contained within the site, allow for these circulation elements to expand beyond the site. Through the energy access map on GIS, one can see which residents of Paraisopolis are sharing power through their neighbors, tapping directly into power lines, etc in Paraisopolis. Instead of having residents plug into power lines for energy, the circulation network will bring the energy to them.
The ramps/walkways are to be set within a plug-in, scaffolding structure that aims to act as: hillside retention, structure for new and future construction, shoring for existing favelas, adjustable structure to deal with changing condition of Paraisopolis. Also, in order to take advantage of the open space below these elevated walkways, a system of terraces will be developed that can allow for farming plots, recreational fields, drain/collect stormwater, etc. So essentially several layers compose the entire site deployment: structural grid, scaffold structure, ramps/walkways, terraces. Thanks!
A series of images documenting my process over the past couple of weeks:
1. Two images from last week’s pinup, showing the beginning of a second system used for shading (the zig-zag canopy).
2. One topographical plan at the scale of Paraisopolis and its surroundings – I’ve been looking at how our site is only one of many sites which form a strand of connected basins, flooding following rainfall.
3. Two images from a recent iteration of my striation vocabulary, modulating steps on the hillside to retain earth, and begin to define program areas. I intend to refine the second vocabulary of the shading canopy and make it work better with the striations.
Due to the nature of the topography in Paraisopolis, and the superimposition of the grid road system, there are areas in Paraisopolis where the roads are too steep for bicycle use. Initially, I proposed a system of elevated bikepaths/walkways that would be integrated with the road system of Paraisopolis. Per the comments from last week, I’ve adjusted the system to only cover the negative areas around the site. The elevated system would connect the high points around the site with a gentler slope, making it more comfortable for cyclists and pedestrians.
Alternate modes of transportation, like tricycles and pedicabs, can be used on the elevated systems. The idea is to activate flow or movement around the favela, which could promote tourism, and in turn encourage the residents to create new commerce. Residents can build up to the elevated system and open shops or services along it.
On the site, the system would link the grided streets adjacent to the site, and the two roads located above and below the site. The anchor building will act as a terminal will be integrated with the elevated system on the site. The terminal will be be an extension of the elevated system as well, it will contain a pedicab hub, market stalls and possibly a car park. This is to encourage people to use alternate modes of transportation.
After plotting points at the corners of every favela construction (mapping the points of existing columns+footings), I was able to analyze the density of construction across the area of Grotao and compare that with the slopes of topography.
The farm network I’m proposing would be supported by pouring more concrete around columns of existing houses and footings of cleared houses. The previous constructions of Grotao inhabitants would be a narrative for determining the specific supports and morphology of the farm network, with minimal intervention and maximum impact. A large number of small supporting columns would form a rigid network structure when linked by the surface of the farm, winding its way around existing housing. Light access to existing housing windows would be largely maintained due to the narrow nature of the farm, casting less shadow. This system would grow over time and respond directly to the immediate context in how it wound its way around houses/paths/slope, having the same dynamic construction as the original housing.
The reasons for elevating the farms are: 1. minimal impact on existing structures 2. access to sunlight 3. potential for electrical/plumbing/drainage network 4. food security thru disconnection from ground.
I am working on the specific parameters of the system and the rules in which they would negotiate the existing context.
When developing social housing projects, great life quality issues are attended, with low and very limited budget and time to dispose of. Given this situation, efficient and practical projects are stated where the possibilities of answering the final user’s identity are reduced. These “standard” solutions often shows indifference to the reality of the individual; the alley used for recreational and distracting activities is changed by stairs and hallways of the new building. Although sometimes it provides comfort, the user is forced to change his activities without considering its side effects in the future.
Would it be possible to understand the truth essence of the inhabitant of Paraisopolis and stamp these principles in an architectonic project? Instead of establishing formal rules to a population that has showed an incredible capacity of adaptation, we could try to understand the improvisation and informality as a life style.
PROJECT. To state the norms and limits that allows the user to be the center and main character of its own space. A building with mixed uses, with expansible units. Each living or commerce unit made up of a BASIC AREA, where it’s intended to satisfy the basic needs, and an EXPANSIBLE AREA, where the user is allowed to design and personalize its own space.
To create a Master Plan that covers housing, commercial and educational issues based on different types of expansible units.
Open Axis of Bridges, Ramps, Walkways. Provide connections not only within Paraisopolis, but also to the rest of Sao Paulo. Bridge the Gap : physical, social, economic barriers. Engage the diverse conditions of Sao Paulo in such a manner that disrupts the norm. Connect Paraisopolis to Sao Paulo’s Metro / System; thus, reducing commuting time and increasing travel distances = opportunity? Increase mobility to the extents of Sao Paulo rather than the immediate periphery of Paraisopolis. Opportunity = jobs, vocational training, higher education, larger client base for businesses, tourism, etc.
Create Kinetic Pathways – that engage the user and generate energy via kinetic surfaces and installations along circulation infrastructure. Engage high traffic and sports along these Energy Corridors in order to utilize human activity to generate energy. Apply resultant energy to power lighting, and create plug-in stations to power portable devices. Infrastructure as Architecture; infrastructure that accommodates sports fields, transportation, training and educational centers, etc.
Flexible Infrastructure: pedestrian bridges, ramps, walkways flex according to program and adapts to the changing conditions of Paraisopolis. Speculate that if the favelas continue to rise and stack, the circulation infrastructure must be able to ascend. Design Plug-In Structure that allows for interchangeable infill / surfaces – turf, plants, grate, recycled materials, etc. as the programmatic function of these corridors may change seasonally.
I like the idea of a “kinetic pathway” and there are many interactive installations on bridges / walkways that can be looked at (more on that later) It depends on which sorts of scales you want the interactions to occur. And these scales need to be determined by site-specific research, as there are many different possibilities for such a broad topic.
Such research of current interactions in Grotoa’s public space will greatly inform your design and also ensure its success/efficiency. It is a matter of perhaps tweaking/accentuating existing patterns and converting them into the productive source of energy you describe.
Low-tech ideas like wind-up energy could be interesting to use in conjunction with games along the path.
A very nice project to do with sound-generation, is “Tuned Stairs” by Fabrica. They connected a glockenspiel to a staircase in the Pompidou, making it a hub of activity and a joy to walk – I remember hanging out with people of all ages, all of us making plinky-plonky music together. Perhaps such a simple idea could be modified to an instrument that is used in Grotoa and connected to energy-production somehow?
The intention of this project is to generate an operational landscape of site stabilization, where architecture is embedded in a thick system of walls for both hillside retention and stormwater management. The goal is then to produce a continuous edge condition where circulation and occupation coexist, beginning at the existing roads that surround the area and criss-crossing the site–dotted continuously with points of entry and exit. After looking at a series of erosion control systems, the hope is to develop a new modular unit that acheives this, one that hybridizes the unique strengths that my partner and I found in some of those systems.
The idea is to build out the site using a large amount of existing material, to apply a cut-and-fill strategy both to the soil and to the remaining materials on site (previous foundations, roof metal, etc) to minimize the difficulties of bringing new material into the area. Since the site is dominantly clay, it could be a productive landscape of brick or tile production, where perhaps the construction of the cut-and-fill landscape, the modules that comprise it, and the subsequent Community Building, are dominantly the products of a new local economy. Under such a scenario, perhaps the facilities that are used for such a production are built first, and at the end of the cycle transition their purposes to day-to-day life in the community, where drying and storage areas become open public plazas, bathrooms either harvest the stormwater or dry-compost for landscape, and kilns are cleaned and repurposed to ovens in a community kitchen.
Integration through Transportation and Transit Links
To create a transportation hub on the site in order to make the favela more accessible from the outside.
Following with the previous objective, to create a public center that can attract not only people from the favela, but people from the city proper as well.
To introduce energy efficient and low impact transportation systems.
Proposed Transportation Systems & Strategies:
- Introduction of Funicular Railways along the steep slopes of the favela. A funicular or incline railway can be called an elevator-railway hybrid since it combines the technology of both. In a funicular, two trams are connected to each other with a cable that runs through a puller at the top of the incline. The counterbalancing of the two cars (with one going uphill and the other downhill) minimizes the energy required operate the railway. Funiculars can be installed on the steeper slopes around the site – particularly on the northwest and east slopes of the site for a more direct access.
- Re-routing of the roads adjacent to the site for better accessibly for private and public vehicles [Via Projetada GR-01 and Via Projectada GR-02 in particular].
- Introduction of greener transportation alternatives (public and private).
The transportation hub on the site should also serve as a destination for the people in the city. Introducing a public park and marketplace, while providing parking space for visitors can be the first step in opening the favela to the city (which will hopefully lead to integration).
- Open-Air Market: The greenspace to the east of the site can be converted into farmland, and serve as the source of the goods sold in the marketplace. A funicular railway could give direct access from the farmland to the site.
- Community Park: Green roofs may be employed on the marketplace, which then could serve as a public park for the local residents and the visitors to the site.
One article in particular has the title “THE END OF TRAMWAYS” and had an interesting argument for abolishing this mode of transport – something to keep in mind perhaps, at this stage of your project:
“EXIT THE TRAMCAR
Horse-drawn tramcars had been running in Mumbai since 1874,. When the electric tramcar appeared for the first time in the city on 7th May 1907, it was given a warm welcome as a very modern mode of transport. When the bus arrived on the scene in 1926, the tram-car ceased to be modern; but this did not affect its usefulness. In fact it became quite important as the poor man’s transport’ and continued to be so till the Second World War. The years that followed brought dramatic changes in the life of the city. Its population started growing rapidly. The people wanted faster transport. the tramcar was, however, innnocent of the fast-changing environment and it continued to rumble up and down, in its 1907 manner. There was, of course, little scope for improvement. If anything, it moved at an even slower pace, thanks to the congestion on the roads. It found the crowds bothersome and the crowds found it a clumsy, lumbering impediment to the smooth flow of traffic. The poor thing had no place in this swift-changing city. It had to go. The city had already started thinking of quicker substitutes for it.”
The article provides several alternative modes of transport which might be something to explore: (1) Aerial Ropeway, (2) Underground Railway, (3) Overhead Railway (Aerial Monorail), and (4) Water Bus
Intention: to create a networked system through systematically placed hubs which will facilitate localized living. This aquatic pavilion will provide conditions for survival with minimal resources. As a means of improving its environment, this space serves as a bio cycle: it will collect and purify water, create food security through the implantation of hydroponic gardens, introduce commerce through the sale of excess crops, while simultaneously engaging the community. This pavilion is more than an open urban garden; it is a catalyst for community development.
Points of access will shape the space. A terraced landscape will be formed by the network of connections to, through, and within the site – linking this pavilion to a larger social and urban context.
Hydroponic gardens will grow crops with the water purified on the site. The terraced landscape will provide various plateaus on which the crops are grown. Nestled into the landscape could be small markets or kiosks from which the excess crops could be distributed or sold. These gardens will create jobs while simultaneously creating food security.
Aquatic umbrellas will produce “interior like” spaces, provide shade and collection and purify water, while a constructed wetland acts as a basin to collect and clean stormwater runoff.
The pavilion space serves as an open market, meeting place, and a performance stage.
Creation of a modular system through the use of a repetitive shape – triangle, hexagon, crest, – will create surface and space. This simple shape would allow the implementation of complex geometry -insuring that this technique could be introduced into other “hubs.”
When I read the description of your project, the first thing that comes to mind is the “Park Fiction” art collective, working in the St. Pauli district of Berlin. For 10 years they’ve been working on an urban community garden, which is now in existence! This is a great article by Momus on them: “Park Fiction becomes Park Fact”
“The Park Fiction group began in 1994, just asking local residents what kind of garden they’d like to see. A Turkish girl suggested a youth cafe with letter boxes for kids whose mail is monitored by their parents. A Russian couple wanted an avenue of friendship lined with rose bushes. The artists coined slogans: “Desire will leave the house and the realm of boredom, bringing the administration of misery to an end” and “Art and politics make each other more clever”. They planned strawberry-shaped treehouses, treehouses with bathtubs in them, a swimming pool in the docks, poodle-shaped boxwood hedges, an open-air cinema, a hedge maze, a pirate well, a open-air Solarium, a flying carpet of wavy turf, and artificial floating islands with palm trees.”
Interesting points to examine from this project: + collaborative design process + interaction with the community + fantastical elements of the design + documentation / communication: pamphlets, films + slogans / strong themes as a guiding force + PLAYFULNESS
Approximately 20% of Sao Paulo’s population reside in favelas, more than 2 million people. As a result of the dense population and lack of infrastructure, favelas such as Paraisopolis are faced with an energy crisis. Oftentimes the residents are forced to tap into existing power lines, an endeavor that is both risky and illegal in order to power their homes and businesses. With an ever increasing population, the need to supply Paraisopolis with its own energy infrastructure becomes crucial. In order to address the soaring energy need of Paraisopolis, large scale systems as well as marginal sources that can be set up and maintained by the residents of Paraisopolis will be defined. Considerations while investigating these systems included cost, footprint, and energy output.
Geography and Topography of the site: Rainwater = 1/2 year long
Soccer Field: Nice idea, but the soccer field is rather large for such a concept: another site with smaller footprint and higher intensity of activity would be better. See Feedtank’s interactive dance floor
Kolkata, India Aquaculture: A Case Study in Wastewater Reuse
Below is a case study of the wastewater reuse aquaculture system in Kolkata, India.
Kolkata, India Aquaculture: A Case Study in Wastewater Reuse
Providing sanitation is recognized as being of prime importance in improving the general health of populations. By providing sanitation, infant mortality caused by communicable diseases, such as cholera, typhoid and diarrhoea is greatly reduced, as is the incidence of severely malnourished individuals with associated physical and mental health problems. The World Bank has suggested that life expectancy in communities generally increases as a result of providing sanitation. Inadequate sanitation results in the degradation and contamination of groundwater and surface water, in such situations it is often recommended that contaminated water be boiled, a process that uses large amounts of fuelwood. The combustion of which results in atmospheric pollution and may lead to an increase incidence of respiratory disease.
Sanitation needs are crucial in informal settlements where most of the migration to urban centers is landing at a rapid pace. The illegality of these informal settlements means there is little to no government resources to build the needed infrastructure to deal with the rapid increase in raw sewage and other wastewater. A common feature of low income settlements is untreated sewage running freely through the little open space available in these typically dense settlements. Even in Sao Paulo, Brazil, where government programs exist to upgrade the infrastructure in informal settlements, untreated sewage runs in open concrete channels which ultimately flow into the city’s river system, contributing to the eutrophication of the city’s watershed. This problem is especially acute in the informal settlement of Canthino do Ceu, which is located on the edge of one of Sao Paulo’s drinking water reservoirs.
Christian Werthmann’s class, Green Infrastructure in the Non-Formal City, asks students to research green technologies in order to develop a tool box for infrastructure upgrades in informal settlements through the lens of two informal settlements in Sao Paulo, Brazil – Canthino do Ceu and Paraisopolis. While both are impacted by untreated sewage, finding a wastewater treatment solution for Canthino do Ceu has been the focus of my research because of its adjacency to a drinking reservoir and its relative abundance of land. My research trajectory has been to find technologies that not only treat wastewater, but also provide benefits culturally, economically and ecologically. In essence, to find ways to not waste wastewater, but to utilize it as the resource it is.
While there are different technologies that convert human waste (aka “resource”) into electricity, gas or heat, I am interested in its agricultural application for several reasons. Firstly, human “resource” contains the same nutrients in commercial synthetic fertilizers – nitrogen, phosphorous and potassium. Secondly, the residents of Canthindo do Ceu are already practicing urban agriculture as is seen in aerial photographs. Additionally, we learned from Elizabete Franca, from the Favela Bairro program in Sao Paulo, that the residents have a close connection to the culture of their hometowns in Northeast Brazil. Assuming that food is central to cultural expression, I figured that the encouragement of urban agriculture will be accepted here over Paraisopolis, where the population equates the farming culture of Northeast Brazil with low social status. By designing a way to combine wastewater treatment flows with agricultural flows, we could economically close the nutrient loop of wastewater as well as provide an efficiency of uses. Food production with wastewater effluent could 1) mitigate contamination of the drinking water reservoir, 2) provide sanitation for residents, 3) provide inexpensive, fresh food locally, 4) provide cost-savings on food expenditures, 5) provide cost-savings on fertilizer, 6) provide a cottage industry and 7) has the potential to build community and create safe public spaces.
My research found that the practice of fish farming (aquacultre or aquaponics) with wastewater effluent has the greatest potential for social acceptance and the least contamination issues. This method of closing the loop with regards to wastewater and food production is also known as integrated biosystems. One of the most famous and most cited examples of this type of managed reuse of waste resources are the aquaculture ponds in Kolkata, India. According to Mara and Cairncross wastewater reuse through aquaculture, which occurs predominantly in urban settings, could be an important component in the sanitation strategies of poor communities in developing countries. The focus of this paper will examine the Kolkata aquaculture as an in-depth case study. Before I begin, however, I would like to outline some of my previous research trajectories to show a brief comparison of the benefits and constraints of alternative reuses of wastewater.
First, I investigated the technologies associated with wastewater irrigation, but the lack of consensus regarding its public safety made it unfeasible. Most researchers agreed that wastewater irrigation could not be used on crops that would be eaten raw. Its use was limited to crops that would be processed, such as industrial crops like wheat, sugar, corn and so forth. The uncertainty over the pathogen presence ultimately gave wastewater irrigation an unshakable social stigma.
Secondly, I investigated the possibility of utilizing pure urine as a fertilizer, since urine doesn’t contain any pathogens and has high levels of nitrogen, which is a key component in accelerating plant growth and crop yields. The problem here is the oversupply of urine from Canthino do Ceu’s 65,000 residents. Since urine is applied as a fertilizer, about three times a growing cycle, at most, there would be a sizable surplus. It is probable that the surplus could be manufactured into a fertilizer for export to neighboring farms and retail garden centers. However, the cultural element of food production would not be fully realized in this scenario. The cultural stigma of urine fertilizer and the lack of precedents constrained the full potential for this research trajectory. Even though, it is quite experimental it may still be a feasible avenue to deal with part of the wastewater at Canthino do Ceu and to provide some residents with a cottage industry in organic fertilizer production.
Lastly, I found a body of research and case studies on integrated biosystems, which are based on natural systems of nutrient cycling and recycling. These systems offer any combination of sewage treatment, aquaponics (growing fish and plants in the same tank), aquaculture (fish farming), wastewater irrigation and biogas (producing gas from biomass) technologies in response to the size and goals of any particular site. Whereas conventional wastewater systems are linear (wastewater to treatment facility to dumping in natural water body), the integrated biosystems are closed loop systems that use and reuse the resources in waters of varying qualities. Ultimately, the system is able to provide low-cost water filtration by maximizing water resources and localizing nutrient outputs. This systemic thinking, is not only able to capitalize on nutrient resources in wastewater and effluent from various wastewater treatments, it also helps contributes to the health of the overall watershed. If designed in the public realm, integrated biosystems could help promote awareness on how human sewage and land use affect water quality.
The Kolkata aquaculture system is the most famous example of integrated biosystems and have served as a model for how to develop these systems in urban and peri-urban conditions. They are cited in numerous research paper written on the topic of combining wastewater treatment with fish farming. Moreover, the Kolkata aquaculture ponds have become so important to the ecosystem of the area that they are recognized by the United Nations honors and are protected by the local government.
The practice of Kolkata aquaculture began in 1850 when the River Bidyadhari contained tidally influenced, brackish water. The intensive use of the river as a source of irrigation caused the river to lose its flow in 1928. For the next couple of years, farmers began experimenting with the usage of sewage to cultivate fish.
From 1930 until now, farmers have orally passed down their methods of farming from one generation to the next. In 1988, researcher Dhrubajyoti Ghosh canonized the aquaculture design and schedule of activities in his paper, “Wastewater-Fed Aquaculture in the Wetlands of Calcutta – an Overview” Figure (1) is a diagrammatic section of the pond design he described.
The ponds are flat-bottomed and dug to the shallow depth of 50 – 150 centimeters. This allows the strong tropical sunlight to sanitize the pond water.
The banks of the pond are about 3 – 5 meters wide and are planted with water hyacinth. The water hyacinth provides bank stabilization, shade for the fish, and biofiltration of the wastewater by capturing phosphorous on its roots and taking up other nutrients into its biomass.
A silt trap ditch, measuring 3 meters wide, is dug around each pond. This area is where deposits of silt and sewage sedimentation are put during the course of the harvest season, in order to maintain the right depth of the pond. The silt build up also strengthens the pond’s edge.
At key moments during the year, human and industrial sewage is permitted over the pond edge. It should be noted that even though the sewage has not been treated in a conventional wastewater treatment plant before it is released into the fish ponds, it has been diluted and biofiltered as it has traveled from its source through the Kolkata wetlands. The nutrients from the sewage cause algae growth, which then serve as fish feed. This cuts out the expense of fish feed, which is one of the more expensive elements in a typical industrial aquaculture operation.
While fish consumption, sunlight and water hyacinth uptake biofilter the sewage water, the effluent from the fish ponds still contains nutrients from fish waste. The effluent from the Kolkata fish ponds then irrigates rice paddy fields.
Overall, the Kolkata aquaculture system has the characteristics of a lake, where the water is neither completely free-flowing nor static. It is completely aerobic at all times during the fish’s life. There is a constant, slow-paced flow, which means that the system essentially acts like a facultative pond in a conventional wastewater treatment system, but at a decreased cost and with added productive value.
The schedule of fish farming in Kolkata is a year-round process that can garner several yields of fish per year, depending on the fish species being raised. Fish farming employment in Kolkata offers profitable year-round full time jobs for many of the families in the area. A breakdown of the overall schedule can be found in Figure (2).
During the first phase, the fish ponds are prepared during the coldest time of the year because the fish prefer warm waters.
During the second phase in mid-February, diluted sewage water is introduced to initiate the fertilization of the ponds. The pond water then stabilizes for one month. And at the end of this phase the pond is stirred vigorously to reduce any anaerobic conditions and to promote benthic organisms for fish to eat.
The first step of fish stocking in the third phase is to introduce a few small fish into the pond to test the water quality. Once the fish display healthy characteristics, fish are stocked. Ghosh did not mention whether the ponds accommodated polycultures or monocultures of fish. He just continues to describe the different schedules of stocking and harvesting for popular fish species. For example, Indian Major Carp can be stocked twice a year. The first stock happens at the ratio of 50 – 60 fish per kilogram of water. The second stock happens at the ratio of 10,000 – 40,000 fish per kilogram of water. Silver Carp are stocked in July at the ratio of 400 – 600 fish per kilogram of water. The Common Carp is stocked in December at the same ratio of 400 – 600 fish per kilogram of water.
During the fourth phase, a second wave of fertilization from the diluted sewage water is introduced into the fish ponds. The amount and frequency of this fertilization depends on the fish species, however, the amount is much less than the initial fertilization. This time only enough sewage is allowed to encourage plankton growth.
The last phase is the fish harvest. The Indian Major Carp are harvested between May and July, while those stocked second are harvested between August and October. Silver Carp are harvested in December. While the winter months are the safest to dry and prepare the ponds, if fish culture continues, fish harvesting is also done at this time. Large teams of 10 – 20 fish farmers collaborate to harvest the fish using nets. Typically a supervisor is present to offer general directions and optimize the haul. The fish harvest phase is indicative of the social and land organization present in the Kolkata aquaculture system, wherein most of the farmers lease their land and 300 operate in farmer cooperatives. The fish are then sorted in a boat and the selected fish are taken to the nearest auction market where they are sold to “bidders” alive. The bidders then take the live fish to retail markets within the hour. The fish harvest is able to fulfill the high market demand for fresh fish in Kolkata to all social classes, especially the poor.
In 1998, 3,500 hectares of land containing 250 fish ponds utilized 15 million litres of sewage per day in Kolkata. This amount of sewage made up only a third of the total sewage outflow at that time. The system produced 8,000 tonnes of fish per year, employed 2 people per hectare, produced a fifth of the fish sold in Kolkata, provided a clean food source and supported 4,000 poor immigrant families from Bangladesh. The aquaculture practice also spawned peripheral economies in fish farming accessories and fish trade, which employed 20,000 people.
In summation, the Kolkata aquaculture provides three basic human securities: food, sanitation and livlihood. The list of benefits goes beyond these basic necessities to include the provision of a fresh source of protein to urban markets, reduced resources for transportation of food, stormwater drainage, low-cost wastewater treatment, reduction of eutrophication in the watershed and green “lungs” that improve the health and well-being of urban residents.
The Kolkata aquaculture is not without its constraints. Recent industrial development around the Kolkata fish ponds is comprising the system with increased flows of heavy metals. While this has presented some challenges, there isn’t any consensus on the levels of contamination in the fish. Additionally, studies in 1994 and 1996 found indicators (including land area, people employed and financial viability) that suggested that the Kolkata aquaculture was in decline. There are also problems of fish poaching, job loss to higher wage jobs and lack of wastewater fertilizer.
The applicability of the Kolkata aquaculture to Canthino do Ceu in Sao Paulo, Brazil needs more investigation into the specifics of the site. There seems to be potential in the fact that 83% of Sao Paulo’s sewage is untreated; the Brazilian aquaculture industry is growing (Figure (3)); and, Canthino do Ceu has a fair amount of unoccupied land. According to my estimated calculations, 43 tonnes of fish could be harvested per year from the 640 million litres of human sewage generated in Canthino do Ceu per year. This would result in low-cost sewage treatment, livlihood for many families, cost savings on food and the provision of nutrient rich irrigation water to other forms of urban agriculture.
The largest constraint for application is the amount of land required to first treat the sewage, then utilize in fish ponds and then to distribute its effluent. Using integrative biosystems as a guide, I will have to combine several technologies that are more scale appropriate. Urban agriculture groups in the United States and indoor aquaculture systems offer models of a more compact scale.
Growing Power in Milwaukee, Wisconsin uses an indoor, compact aquaponics system. In this system, fish and vegetables are grown in the same tank. The nutrients from the fish waste and fish feed work double duty to supply nutrients to the vegetables growing hydroponically in the tank.
The Rhizome Collective in Austin, Texas, as well as Greywater Guerillas in San Francisco, California have built low-cost vertical wetlands to biofilter greywater. I will have to investigate the capability of these systems to biofilter human sewage.
There are also many examples of indoor, high-tech aquaculture systems that focus on saving space and high productivity. While these systems may be more expensive and high tech, they could provide informal settlement dwellers with high tech training and skills.
Another site application strategy I could try is to work backwards. First, I would determine the amount of suitable and available land. Then figure out how much aquaculture sewage treatment could be accommodated on that size of land.
Ultimately, it has been interesting to learn about the model project that inspired a generation of integrative biosystems that will surely help us to better manage our resources in the future.
Melissa Guerrero GSD 6445, Green Infrastructure in the Non-Formal City, Christian Werthmann 04 11 08
Energy Usage for Sao Paolo Favela Households: Biogas in Context
Energy Usage for Sao Paolo Favela Households: Biogas in Context
This paper for seeks to triangulate energy needs for Sao Paolo favela communities such as Paraisópolis and Canthino do Céu. Triangulation here denotes extrapolation between general information on sustainable technologies for energy production and English-language literature relating Brazil’s energy policy in low-income settlements. The research explores energy poverty in Brazil and energy usage and preference at the individual favela household level. Considered with the 6445 class biogas group research the potential impact of biogas production as green infrastructure in the favela context can then be formulated.
Residential sector energy policy in Brazil
In recent decades, Brazil’s national policy objectives have sought to incentivize rural settlement and growth of mid-size cities, in order to counter the explosive growth of large urban conglomerations. Such approaches have been less successful in practice; however, rapid urbanization peaked in the late 20th century while the coupling of economic development and social disparity continue into the new millenium. Favelas today function in parallel to the formal city, housing much of the service sector and the informal economy: since 1990 half of Brazil’s jobs are in the informal economy, and in Sao Paulo one in five live in favela communities. (Boa Nova, 2001; pp. 1-2)
Macroeconomic reform begun during the 1990s has shown limited success stabilizing the national economy, but has also complicated competitiveness of the informal economy and increased levels of urban poverty. Transfer of services from public sector to private companies through deregulation and utilities privatization has triggered increases in cost of service provision by 2-3 times that of inflation over the same period. (Winrock, 2005; pp. 10)
Energy policy since liberalization has responded mainly to forces of industrialization and related corporate lobby, with less weight given to the social policy needs of low-income communities and informal enterprise.
In terms of household consumption, the three primary energy sources in Brazil are LPG cylinder, electricity and gasoline (primarily automotive). International cost of petroleum directly affects not only LPG (a petroleum derivative), gasoline and diesel, but also public and private transportation costs. Energy requirements for the majority of small and medium-sized businesses in favelas are typically associated with individual households. (Winrock, 2005; pp. 10)
In terms of relative cost differential, LPG has shown the highest cost multiplier since market reform of the 1990s. From July 1994 to June 2003, the cost of LPG has increased 550% or three times the inflation rate. Virtually all urban households in Sao Paolo and Brazil rely solely on LPG for cooking. Electricity over the same period increased by 305%, or twice the rate of inflation. Government subsidies have kept the cost of gas and diesel artifically low. (Winrock, 2005; pp. 11)
Energy constraints on sustainable livelihoods
Planning for sustainable energy is increasingly cast as a critical dimension of international development policy. A 2005 research study conducted by Winrock International, in conjunction with the Technology and Development Group of the University of Twente (Netherlands), describes the linkages between energy policy, sustainable livelihoods and small enterprise in the Brazilian context. Winrock notes that the literature in Brazil relating energy with gender and poverty typically focuses on rural areas. The Winrock research in contrast studies the urban case in order to fill the “knowledge gap” with empirical data on the micro-level impact of privatization of energy sector on the informal economy.
Key policy recommendations were tested in two poor neighborhoods of Salvador, Bahia using micro-level gender disaggregated data (514 households total, 259 in Plataforma and 255 in Canabrava): that clean, affordable energy has a positive correlation with physical well-being and productivity of urban households; and that the relationship between energy services and energy sector reform directly interfaces with social networks and urban (micro-)enterprise. (Winrock, 2005) (Winrock, 2005; pp. 44)
The Winrock study cites earlier data that shows the breakdown of energy consumption in the residential sector and finds that energy source by application is similar for households in the low-income communities of Plataforma and Canabrava in Salvador. LPG is the primary energy source for cooking and food preparation, and a secondary source for water heating and lighting.
The survey also observed high incidence of informal (unregistered) businesses run out of the households studied, including production/sale of food and beverages, hairdresser and seamstress/tailor. The majority of these enterprises earn less than R$500/month and their limited operation as micro-enterprises is essentially an extension of household activity. Average monthly use of LPG when households include on-site businesses is closer to two LPG cylinders/month, with default household usage more generally between one and two LPG cylinders/month. (Winrock, 2005; pp. 56)
Electricity is most prevalent energy source (30-40% of business activity), and LPG was second more reported energy source (27.4% of food processing-based businesses). In terms of machine equipment utilized in business activity, the stove is most-reported (19%).
Percentage of family/small businesses, according to equipment used in the business:
(Winrock, 2005; pp. 60)
ESMAP’s 2006 case study on the Caju shantytown in Rio de Janeiro provides additional information regarding energy usage in Brazil’s low-income communities. Caju constitutes 17,500 people in 6605 households with an average per capita income of R$250/hh, residency rates of 3.5ppl/hh, and rate of employment in formal sector at 0.8 formal jobs/hh. 42.4% of Caju households have average per capita income higher than minimum wage (R$200), and approximately 15% households exceed technical definition for poverty in Brazil (greater than three times minimum wage). (ESMAP, 2006; pp. 22)
Brazil’s federal government offers energy subsidies for households using less than 220 KWh; the intention is to make available aid to the poorest households. However, ESMAP explains that recent research has demonstrated that there is no correlation between poverty and energy consumption per household. Poorer households may use less energy per capita, but have larger household sizes. (ESMAP, 2006; pp. 39) ESMAP offers that this policy failure may drive the network of extra-legal energy supply (e.g. gato connection to electricity).
ESMAP also notes that while virtually all urban households in Rio de Janeiro (including low-income households) depend on LPG for cooking fuel, distribution of LPG cylinders is controlled by organized crime in direct proportion to level of poverty. That is, the most poor households are most subject to the organized crime “tariff” (up to 20% over actual cost) although wealthier households pay for LPG at-cost. It is unclear whether this condition is unique to Rio de Janeiro or is a general indicator of energy economics in favelas.
Share of energy expenditures are particularly revealing. Given existing payment schemes for electricity (originating from the initial phases of slum electrification) and the organized crime “tariff,” most households pay effectively equivalent amounts on electricity and LPG. Adjusting for full payment of electrical consumption, and elimination of LPG price distortion, all households in Caju will pay 6.6 to 14.2 percent of income (9.8 average) on energy.
ESMAP notes that the standard definition of energy poverty is allocation to energy costs of ten percent or more of annual income (five percent for poorest 30 percent of population). Following this metric, all income groups in Caju would qualify as “energy poor,” although ESMAP does suggest that perhaps the five percent standard needs to be reconsidered in the economic structure of Brazil.
The ESMAP study also offers several points of data relevant to estimating energy needs for residents of Paraisópolis and Canthino do Céu.
LPG expenditures can be estimated as one 13 kg cylinder per month for a family of four. In 2002 the unit cost of LPG cylinder was R$20, but ranged up to R$28 or R$33, given the surcharge of organized crime to certain constituencies. (ESMAP, 2006; pp. 31)
Calculated from the total annual electricity consumption for all 291,562 shantytown households in Rio de Janeiro is 580 GWh, the average favela household in Rio de Janeiro consumes 1990 KWh annually, or 166 KWh/month. (ESMAP, 2006; pp. 37)
CENTROCLIMA and COPPE state the average electricity consumption per favela household in Sao Paolo at 175 KWh/month. The utility company Eletropaulo, under federal regulation of electrical tariffs, charges for an equivalent of 50 KWh to favela-dwellers; this translates to a monthly bill of only US$1.75 instead of actual usage at full rates US$9.40 plus taxes. (La Rovere et al, 2004; pp. 130)
Summary of per favela household energy usage:
13-26 kg LPG/month, 156-312 kg/year (typical favela) 3% of income, 2.6% under proposed costing restructure (Caju, Rio de Janeiro)
±175 KWh/month electricity, ±2100 KWh/year (Sao Paolo favelas) 3.4% of income, 7.2% under proposed costing restructure (Caju, Rio de Janeiro)
Biogas consumption rates (Sasse et al, 1991; pp. 80)
Household burner: 200 – 500 L/h Refrigerator (100 l volume): 30 – 80 l/h Gas lamp: 120 – 180 l/h Biogas/Diesel engine per bhp: 420 l/h Generation of 1 kwh electricity: 700 l Biogas production Natural gas production in Brazil
CENTROCLIMA/COPPE show that the IEA projects that natural gas will expand market share to 35 percent of Brazil’s power generation by 2030, up from 5 percent in 2000. Natural gas production in 2006 is 23.2 billion cubic meters, although IEA anticipates built-up to 70 billion cubic meters by 2030; the deficit is expected to be met by natural gas imports, especially the Brasil-Bolivia pipeline. In 2001, Petrobras alone flared off 8 million cubic meters of natural gas. (La Rovere et al, 2004; pp. 82-83) New legislation now makes such practices illegal, and natural gas transport infrastructure is being scaled up nationally.
As a renewable energy source with performance comparable to natural gas, biogas is already entering a stage of significant development in Brazil, partly due to the international carbon trading scheme established by the Kyoto Protocol. Such projects tend to be either agricultural (large-scale animal-fed biogas production) or peri-urban methane reclamation from urban landfills. Rural projects are successful but usually limited to on-site use of the biogas generated. Biogas production from landfills and wastewater treatment plants is now seen as viable only after several proof-of-concept projects over the past decade. Sao Paolo state today now has a 20MW plant generating electricity from biogas, together with a constellation of 50-500KWh facilities. (Alves et al; pp. 1)
Biogas is generally seen as a growth industry in Brazil with substantial foreign direct investment potential, but nontrivial challenges remain in terms of deploying biogas production within the urban fabric, particularly in favela communities.
∙ Balancing cost of infrastructure against the lifetime return on investment and the associated delivery cost for biogas/energy produced. Urban siting demands innovative approaches to achieve cost-effective production density.
∙ Projects such as the Canabrava landfill-biogas effort have met with strong opposition from local communities due to perceived lack of direct community benefits. Consequently, a community-based facility should generate biogas for use in the surrounding community.
∙ Localized biogas generation and consumption is consistent with general objectives for decentralized energy solutions and waste treatment. Since it is difficult to transport biogas (certain restrictions apply to CNG) in cannisters, unlike LPG, pipeline connections would likely need to be made between production facility and residential customers.
∙ Determining the ideal scale for production is not straight-forward; is biogas in the city better suited for the individual home, the neighborhood block, or the township/micro-region.
∙ While conceptually energy-from-waste is appealing in today’s era of sustainability, biogas production as a moderate- to large-scale industrial project embedded within the city demands novel approaches for resolving residents’ relationships to/with infrastructure. Bibliography
Boa Nova, Antonio Carlos and Jose Goldemberg, “Electrification of Shanty Towns in Sao Paolo,” conference proceedings for INTA23 conference: The Inclusive City: Cities for the World, Cities for People, The Hague, Netherlands, 2001.
La Rovere, Emilio Lèbre and Ademar Ribeiro Romeiro. Country Study: Brazil. The Development and Climate Project: Phase 1. Rio de Janeiro: Center for Integrated Studies on the Environment (CENTROCLIMA) and Institute for Research and Postgraduate Studies of Engineering (COPPE), Federal University of Rio de Janeiro (UFRJ), 18 March 2004. Final Draft. Available online at: http://developmentfirst.org/Publications/BrazilCountryStudy.pdf
Sasse, Ludwig, Christopher Kellner and Ainea Kimaro. Improved Biogas Unit for Developing Countries. Eschborn: Deutsche Gesellschaft fur Technische Zusammenarbeit GmbH, 1991.
Winrock International. Country Report for the Brazil Project. Enabling Urban Poor Livelihoods Policy Making: Understanding the Role of Energy Services. DFID KaR Project R8348. Salvador, Bahia: TDG/University of Twente (Netherlands) and Department for International Development (DFID – London), November 2005. Available online at: http://www.winrock.org.br/media/Final%20Brazil%20Country%20Report%20-%20…
For GSD 6445 Green Infrastructure in the Non-formal City
Building capacity:// the re-assignment of waterway edge conditions of Sao Paulo's Favelas
Simon Bussiere 4.5.08 Harvard GSD 6445
Green Infrastructure in the Non-formal City; “Investigation” Report:
Q: How can the Favelas best harness (on-site) storm-water runoff in order to produce the greatest residual social/economic/ecologic net benefit?
In the second phase of this research seminar (Green Infrastructure in the Non-formal City: GSD 6445) entitled “Familiarization”, I navigated through and critically analyzed several photographs that Professor Christian Werthmann had taken on his explorations of the Favelas in Sao Paulo, Brazil. Through this macro imaging assessment and a subsequent immersion in contemporary case studies/best practices including the work of Atelier Dreiseitl, Stephen Farber, the Orangi Pilot Project, Wastewater fed Aquaculture in Calcutta and others I am investigating how to best identify opportunities and propose alternative design criteria for the fragile edge conditions of both “unimproved” or disturbed existing streams and highly engineered “solutions/improvements”. Through this exercise it is my goal to better understand “the emerging opportunities of modern sustainable infrastructure for the design of public space” as the datum/direction of this assignment permits.
I’ve drawn from Professor Werthmann’s photographs at five key points along an urban drainage corridor in Sao Paulo’s Favelas to determine a general ratio of impervious to permeable surfaces. The piece of work enabled me to familiarize myself with existing slopes and their contingent visual and topographic impact. In cross-section, the stream corridor reveals a wide set of variables that could be positively manipulated from the tightest alleyways within the highest density settlement patterns all the way to the horizontally sprawling trapezoidal-engineered concrete river beds at the lowest points of the watershed.
Beginning with the premise that conventional engineering principles (under the umbrella of ” storm-water conveyance”) tend to impose a set of abstract assumptions about the quantitative characteristics of water, (deploying a language comprised of terms like sheet flow, peak flow, intensity, duration, discharge, metrics of capacity, etc…) to “capture” and “channel” storm-water as though it were a waste substance that simply needs to be repelled as quickly as is technically feasible “away” from a particular site.
Yet, as the philosopher Foucault reminds us, “Techniques are social before they are technical”…
I would echo this sentiment by asserting that low-tech, low-impact, tactical strategies/interventions utilizing clear and bold gestures of landform and vegetation enable the production of more suitable, empathic, site-specific and cost-effective drainage methods (“solutions”) while empowering/radicalizing on a local level the small-scale community agencies who ultimately contribute, risk, sacrifice and stand to loose or gain the most from the intervening developments within their own sphere of daily activity. Analysis:
Given the proper term of residency in a given storage/reservoir system, storm-water runoff can be filtered and brought to a point of purification that it would not otherwise achieve within a similar condition/context under the “control” of man-made engineering principles and implemented techniques (as is evident from existing interventions). By this I imply that the conventional engineering of drainage does more to increase the contamination of rainfall once it becomes threaded into a matrix of pipes, catch basins and more pipes. Additionally, the same volume of water when squeezed into a calculated network of impervious trenches drastically increases the velocity at which the runoff travels, thus amplifying downstream erosion and deposition as fluid pressure is abruptly released in a sequence of awkward intervals.
The Bernoulli Principle (thumb on the hose effect essentially), “which states that for an inviscid flow,(like a drainage waterway in the Favelas) an increase in the speed of the fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid’s gravitational potential energy. (Bernoulli’s principle is equivalent to the principle of conservation of energy). This states that the sum of all forms of mechanical energy in a fluid along a streamline is the same at all points on that streamline. This requires that the sum of kinetic energy and potential energy remains constant. If the fluid is flowing out of a reservoir the sum of all forms of energy is the same on all streamlines because in a reservoir the energy per unit mass (the sum of pressure and gravitational potential) is the same everywhere”. (Wiki, Batchelor et. al.)
“Fluid particles are subject only to pressure and their own weight. If a fluid is flowing horizontally and along a section of a streamline, where the speed increases it can only be because the fluid on that section has moved from a region of higher pressure to a region of lower pressure; and if its speed decreases, it can only be because it has moved from a region of lower pressure to a region of higher pressure. Consequently, within a fluid flowing horizontally, the highest speed occurs where the pressure is lowest, and the lowest speed occurs where the pressure is highest.” (Wiki)
Bernoulli’s equation is: (actually, go to wiki… jpegs aren’t inserting here for some reason.)
v, is the fluid velocity at a point on a streamline g, is the acceleration due to gravity h, is the height of the point above a reference plane P, is the pressure at the point p, is the density of the fluid at all points in the fluid
“The following assumptions must be met for the equation to apply: The fluid must be incompressible – even though pressure varies, the density must remain constant. The streamline must not enter the boundary layer. (Bernoulli’s equation is not applicable where there are viscous forces, such as in the boundary layer).” (Wiki, Batchelor et. al.) The formula/theory has serious implications for how a drainage channel is designed, and it is a tragedy that the integrity of the principles are not more widely accommodated by the engineering community.
“The above equations suggest there is a velocity at which pressure is zero and at higher velocities the pressure is negative. Liquids (and gasses) are not capable of negative absolute pressure, or even zero pressure, so clearly Bernoulli’s equation ceases to be valid before zero pressure is reached. The above equations use a linear relationship between velocity squared and pressure. At higher velocities in liquids, non-linear processes such as (viscous) turbulent flow and cavitation occur”. (Wiki, Batchelor et. al.)
By re-conceiving the “capture” and “channeling” of rainfall and runoff with the basic principles in the above formulas in mind, the negative processes of erosion and deposition can be mitigated, harnessed and potentially exploited to produce substantial social benefits in the form of a usable resource. In the cross-sectional illustrations in this document I have submitted five “sketch” applications according to these principles.
Basic landform manipulation in terms of grading with berms and swales to harness flowing water, when combined with the thoughtful installation of micro- climate sensitive vegetation with slope-stabilizing root structures, porous reservoirs/dry-wells and concrete stabilized block (CSB) pervious paving technologies can greatly mitigate the naturally erosive ramifications of channeled water ways. The edge condition of such riparian corridors represents the terrestrial/surficial opportunity to intervene with such low-tech materiality and high-concept technique. Some of these are explored in the enclosed cross-sections. See attached.
Eventual program(s) that could manifest from this seminar’s research would be in essence, “Ecosystem Services” driven entities/agencies, capable of generating employment and social accountability through the programmatic filter of active storm-water design/construction/monitoring/management. With net water quality gain as the gauge of the long-term success/sustainability of the initiative, the agencies would function as an Infrastructural Urbanist/Acupuncturist who targets “at-risk”/topographically challenging points/neighborhoods/areas along existing waterways and constructs physical systems with improved means of infiltration, storage and treatment through biotope cleansing, (vegetation) berms, swales (landform) stone/adoquine/honeycomb retention reservoirs, and other techniques for mitigating the release of contaminated discharge while accommodating greater carrying capacities in drainage corridors and contingent water sheds.
Obviously, a comprehensive study (on the ground) is needed to identify exactly what methods and “solutions” are appropriate for specific projects, and within particular contexts, including understanding basic user requirements, local skills and skill levels, local wages and labor structure(s), as well as the larger processes and relationships between the individual, the community, the municipality, existing landscape/architectural features, and the greater civic and cultural obligations to the region as a whole.
Like the Social Forestry Program(s) of the Orangi Project in Karachi, the initial intervention of this proposal could incorporate a “Conservation Trust” to oversee and facilitate operations of a set of grading and wetland vegetation planting schema. The Trust could “hire” itself (employing the local labor force) to work with particular sites, amending areas under poor drainage/erosion circumstances with low-tech means that could be built up over time. (note: the Orangi project began with the “National Rural Support Program”/”Rural Pilot Project”, but an urban context could be similarly modeled. I use the term “Trust” to describe a financial institution which would be responsible for spreading the risk of micro-enterprise credits/loans through individuals and social groups interested in investing in local micro-business.
One such business could be involved in the manufacturing of Concrete Stabilized Blocks (CSB’s) comprised of 9 parts earth, 1 part cement and ½ part polyethylene for flexibility. These blocks/adoquines would be the basic building block of the rainwater reservoirs/dry-wells and would also serve as paving units for certain surface treatments. The reservoirs (as illustrated with complimentary plantings) would provide slope stabilization and simultaneously the scaffolding for the re-assignment of specific edge conditions.
Providing storage or containment of runoff for the purposes of filtration and recharge/reuse and purification into potable water is crucial to the success of the ideas proposed here, but it is also important to note that these CSB’s are only one “seed” project to be considered. Other socially conscious employment generating micro-enterprises are capable of transforming the potential of entrepreneurial/opportunistic individuals and communities in the Favelas.
Within the spectrum of “WATER” services would be micro agencies to monitor water quality at specific points along a stream corridor, and other biological treatment stations which would provide training and further educational/technical opportunities. Implicit in the efforts to reconstruct edge conditions of water channels is the presumption that people have the desire to be laborers. But there are great ambitions among the myriad inhabitants of the Favelas and start-up enterprises related to the improvement of water quality could in turn inspire a generation of Biologists, Ecologists and other creative individuals to raise up their neighborhoods to a higher environmental standard and thus promote and produce a greater quality of life.
1.Poverty Assessment Report No. 20488-NI, World Bank, 2001
2.Document of The World Bank / Report No.: 39868 / (CREDIT 3085-NI) June 4, 2007: Project Performance Assessment Report, Second Road Rehabilitation and Maintenance Project, Nicaragua