José Lenin García Ortiz_Blue stitches for a broken city

BLUE STITCHES FOR A BROKEN CITY

Exploring the potential of drainage basins as backbone for improving the living environment in Las Cruces Mountain Range

José Lenin García Ortiz E.M.U. Thesis TU Delft UPC-ETSAB spring semester 2013

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BLUE STITCHES FOR A BROKEN CITY

Exploring the potential of drainage basins as backbone for improving the living environment in Las Cruces Mountain Range

José Lenin García Ortiz E.M.U. Thesis TU Delft UPC-ETSAB spring semester 2013

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Mentors Ir. D.D. Daan Zandbelt, Prof. Dr. Joaquín Sabaté Bel

Readers Annelies De Nijs - KU Leuven Chiara Cavalieri - IUAV

1. Introduction

Motivation and problem field Aim and approach

2. Research plan 3. Context: Mexico City

Synthesis of the city The water in the city: from Tenochtitlan to present.

Blue broken heart: The problem of water in the city The problem of the suburbs in the drainage basins The problem on the mountains The current approach to fight the water related problems

4. Approach Ecosystem services Landscape connectivity Landscape infrastructure Tools & Models Hypothesis

5. Hondo river Features

6. Strategy 7. Tests

Rural - Huixquilucan de degollado Transition - Huixquilucan Urban - Naucalpan south Urban - Sewage retention basin “CRISTO�

System as result

8. Conclusion

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1.

Introduction

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photography: European Space Agency

1.1 Motivation and problem field: During the last 500 years Mexico City and its ancient lake basin have suffered one of the most major environmental changes in the history of urbanization.

The lake basin together with its lakes fed by 14 big rivers and 35 tributaries, have disappeared almost in their entirety. In the place where lakes and canals were navigated as part of daily life, roads were constructed for years; finally, the area was occupied by a city made of viaducts, ring roads, and boulevards through which millions of cars, buses and trucks move over the former streams.

On the asphalt covered streets, with no capacity to retain and filter rain, rainwater runoff seeks the former streams that run without recharging the aquifer system, constantly threatening with risk of inundation and sinking the city.

Mexico City is surrounded by Las Cruces mountain range to the west, Ajusco mountain range to the south and Nevada mountain range to the east. In addition the city belongs to Valley of Mexico’s basin which also includes part of the states of Mexico, Hidalgo and Tlaxcala (fig. 3.4 & 3.5). In order to drain the basin a canal was made to join with Panuco river’s basin which discharges to the Gulf of Mexico.

The huge works to endow and drain city’s water have played a major role on the bold environmental

transformation of the city. The hope for a city which doesn’t stop growing and destroying its own natural resources, requires a revision of the relation between inhabitants and nature in order to find the common good and harmony.

AMSL) and Toluca Basin (2.400 m AMSL) and where the Madre Occidental mountain range and Neo-Volcanic axis start. Las Cruces Mountain range is 110km long and 47km width at the north and 27km at the south.

This thesis pays special focus to Las Cruces mountain range due to the characteristics of local and regional border, starting point for the water cycle that feeds Mexico City and unplanned sprawled and continuous urbanization. Furthermore, current academic, professional and social attention is paid to the Lake of Texcoco

During the last four decades, urban expansion of Mexico City has occupied a large part of the valley’s plain to the east and to the west has appropriate of Las Cruces Mountain range, occupying an area of 53 x 40 km of uninterrupted urbanization. Taking the mountain range hasn’t been an easy task due the geomorphological conditions of the place and gorges have resisted colonization making difficult the access to this area. However it has been only a physical resistance because the natural functions of the drainage basins have been transformed. This has carried many changes in the ecosystem of the Metropolitan area of the Valley of Mexico.

Currently the Lake of Texcoco is a focal point for academic, professional and social attention regarding the problem of water and ecology in Mexico City. However Las Cruces mountain range play an important role for the lake basin due to the characteristics of local and regional border, starting point for the water cycle that feeds Mexico City and unplanned sprawled and continuous urbanization. For this reason the present work pays special focus to this area.

In a metropolitan level the mountain range is a border between the urban and natural open space, at the territorial it’s a geographical border between Mexico Basin (2.220 m

Metropolitan impact.

Being a border between urban (suburban) and natural open space (mountain range) makes this area very important. On the mountains is where the water cycle that feeds the Valley of Mexico starts, which necessities are not exclusively for human consumption, it is also required to stop the subsidence of the city, preventing inundations, and preserve the

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weather of the region and other ecosystem services.

valley in coma.

One dimension approach

Regional Impact.

Being a morphological border between Mexico and Toluca Basin and discharging in important territorial rivers which discharge to the Pacific Ocean and the Gulf of Mexico, environmental detriment of Las Cruces Mountain range means a huge impact in the ecosystem of the region.

Las Cruces Mountain range feed the Valley of Mexico and the Valley of Toluca, which is place of a system of wetlands named Lerma wetlands and which importance to recover the Valley of Toluca’s aquifer is essential (ref). In addition Lerma wetlands are a sanctuary for migratory birds that fly from Canada (ref) among other wildlife species. Moreover the water used in Mexico City is brought from other regions 240 km away. There are plans to bring water from further away due to the need for more water.

Survivor landscape – broken city The urbanized area of Las Cruces Mountain range (matches the trajectory of the Lecheria – Chamapa Highway) is neither a heterogeneous landscape nor fragmented, it is a broken landscape. On one hand, the city has colonized the geography of the place; on the other hand gorges because of its geomorphological characteristics have resisted the urbanization making difficult the access and interaction among different drainage basins in Las Cruces Mountain range. Moreover the natural function of the drainage basins is inexistent. A drainage basin is a place for biodiversity because it collects and moves the rainwater down to the valley. Now these drainage basins collect and move all kind of pollution down to the valley, the rivers are death streams.

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Geographical and social conditions of the place have caused the city loss continuity and accessibility among neighbouring urban zones highlighting the socio-economical contrasts of the area: On one hill there is a poor neighbourhood, on the front hill there is a rich one, in-between a

With 20,4 million inhabitants (expected 32,312 million in 2050) and located in the Valley of Mexico’s basin Mexico City is one of the most water abundant in the world, however the water management has been a problem and a huge amount of the water (rain in the city and rivers from the mountains) is wasted mixing it with sewage. Urban expansion has contributed to the loss of natural areas which are fundamental for the natural cycle of water and can help to solve water related problems of the city, such as lack of water and inundations, problems which until now only have been fought in one dimension by up-scaling the sewage and feeding system of pipes and ducts.

Moreover transportation in the city is based and supported for private car, even though only 17% of population own one. This policy has supported piping former rivers and streams in favour of roads, mainly high speed freeways that now are congested. Transportation infrastructure (private and public transport) has been developed in the valley however the mountains have been left behind in the plans.

In order to achieve a different future for the third largest city in the world, a revision in the relation between inhabitants and the landscape and its ecosystem is required, and through this process is necessary to investigate what potentialities exist to help in solving other urban problems of the mountain range area, such as accessibility, the lack of public space and urban facilities, the social polarization and the abandonment of the rural areas.

Aim and approach: Since Mexico City is surrounded by mountains this place has a local, metropolitan and regional relevance that has to be explored.

Because the importance of drainage basis and rivers in the ecosystem and the power to structure the urban context of the area, the thesis will address the role of drainage basins, gorges, gullies and water courses as catalyzer and backbone for urban and ecological regeneration of the area.

The objective of the thesis is to investigate the potential of using the drainage basing as a whole system that gives structure and weaves the territory of the mountain with the valley of the Metropolitan area of Mexico City. Defining a strategy based on the understanding of the landscape as infrastructure, it will consider the area in the mountains as the interface to rethink the management of the rivers in the city and link it to the existing urbanization through the open spaces along the water courses.

Finally, to test possible spatial interventions that can transform the drainage basins and rivers in catalyzers of the living environment.

To develop this approach the following steps are made: The first step is to understand the geomorphological structure of the Valley of Mexico Basin, the hydrological system and water infrastructure of Mexico City and the metropolitan transportation infrastructure. A historic revision of two different approaches in the management of the landscape since the pre-Hispanic time until this date is going to be made. By comparing the approaches a better understanding of the current relation between urbanization and landscape and its ecosystem services in Mexico City will be understood.

The second step is to understand what ecosystem services, landscape infrastructure and Transport Oriented Development (T.O.D.) are, how they are related to ecological corridors and how these concepts can be used in rural and urban environments in order to get conditions for a sustainable development of the city.

Third step is the analysis of the area by mapping the most relevant infrastructures defined in the second step, the socio-economic conditions, landscape characteristics (i.e. vegetation, water quality, open-urban spaces, topography). The analysis of these maps will show the potential that each part of the area of study can carry to generate good conditions.

Finally by using some conceptual tools and models from the presented theoretical framework some spatial interventions will be tested not to be fixed plans but rather to investigate the potential of the tools and models in different landscape and urban settings.

This objective will be guided by the following questions:

RESEARCH QUESTIONS: What are the potentials of drainage basins in Mexico City to improve the living environment in the fringes and contribute to solve water related problems in the metropolitan area?

Given the spatial structure defined by the drainage basins, gullies and rivers how to organize the different human and ecological flows?

How the characteristics of the landscape and its ecosystem services can function as catalyzer in Mexico City?

photography: pablo lopez luz

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2.

Research plan

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3.

Context: Mexico City

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photography: www.flickr.com. User: bdebaca

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3.1 Geographical location

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3.

Hidalgo

3.2 Territory

Tlaxcala México

Puebla Total area (ha) AMCM 529,442 ha D.F. 48,323 ha Municipalities 381,119 ha Urban area AMCM D.F. Municipalities

146034 ha 71018 ha 75016 ha

Morelos

Map and Data: MXDF-Centro de Investigación Urbana.Monografía de la Ciudad de México.

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Mexico City is a conurbation (refered as MAMC) of 16 boroughs of the Federal District (Politcal and Administrative Capital of México), 40 municipalites of the State of México and 1 municpality of the State of Hidalgo. With a population of more than 20 m inhabitants is the largest metropolitan area in America. It is located in the central area of the country at 2220 m asl. in the bed of former lake and surrounded by mountains that reach 3870-5426 m asl. The average temperature is 17.2 °c but can vary from 0°c to 25°c during the same day.

40 km

Mexico City - 21.2 m inhab - 84inh/ha

40 km

Tokio - 35.1 m inhab - 47.5 inh/ha

40 km

Randstad - 7.1 m inhab - 44 inh/ha

Aerial views: google earth 2013 Population density: http://www.citymayors.com/ statistics/largest-cities-density-125.html; Randstad: http://www.mlit.go.jp/kokudokeikaku/international/ spw/general/netherlands/ index_e.html

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40 km

Sao Paulo - 19.8 m inhab - 90 inh/ha

40 km

Barcelona - 3.2 m inhab - 48.5 inh/ha

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3.3 Population Density

Map and Data: MXDF-Centro de Investigación Urbana.Monografía de la Ciudad de México.

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3.

Hidalgo

3.4 Administrative areas

Mexico

Tlaxcala

Valley of Mexico’s Basin Federal District

Administrative Boundary Urban area

Puebla

Morelos

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3.5 Topography

Valley of Mexico’s Basin Administrative Boundary Urban area

Las Cruces

Nevada Mountain range

Las Cruces Mountain range

Ajusto Mountain range

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3.6 Hydrology and waste water Valley of Mexico’s Basin Administrative Boundary Urban area Center Las Cruces Rivers Rivers/sewage Surface sewage Deep sewer Underground sewer Water bodies Floodable basins

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600 mm

500 mm

3.7 Rainfall 700 mm

800 mm

1000 mm

1100 mm

Valley of Mexico’s Basin 1200 mm

Administrative Boundary Center Las Cruces

1600 mm

Source: INEGI, sistemas de consulta SIG ;Legorreta, Jorge. 2009;MXDF-Centro de Investigación Urbana.Monografía de la Ciudad de México;

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3.8 Vegetation

Shrubs Induced grassland Agriculture/grazing Forest Water body Urban area Valley of Mexico’s Basin Administrative Boundary Center Las Cruces

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Queretaro

Pachuca

3.9 Roads Public Transport

Puebla Main roads/highways Valley of Mexico’s Basin Toluca

Administrative Boundary Center Las Cruces

Cuernavaca

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3.10 Socioeconomic

Low income Mid income High income Valley of Mexico’s Basin Administrative Boundary Center Las Cruces

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3.11 Type of settlements

Map: Priscilla Connolly. 2005 Source: XII Senso de Poblaciรณn y Vivienda 2000. INEGI.

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photography: Aida Lira; retrieved from implicado.wordpress.com

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3.2 The water in the city: from Tenochtitlan to the present

painting: Tomas Filsinger

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painting: Tomas Filsinger

The built environment as response to the landscape conditions: from Tenochtitlan to the present.

section of Chinampas

The Valley of Mexico was originally an endorheic basin surrounded by Las Cruces mountain range to the west, Ajusco mountain range to the south, Nevada mountain range to the east and Guadalupe mountain range to the north. Inside this basin four lakes, Xalcotan, Zumpango, Texcoco, Xochimilco and Chalco together formed a single lake during rainy season. From these lakes Texcoco was the largest and was salty. The lakes were filled with water from the mountains by 14 rivers which origin is on multiple springs on the higher areas of the mountain and hundreds of seasonally creeks.

On this area, a tribe coming from the north of Mexico founded a city: Tenochtitlan, the city of the Aztecs. Tenochtitlan was founded on an island surrounded by a big lake and the Aztecs started to build its own infrastructure to have one of the greatest cities in history.

Surrounded by water, Tenochtitlan had to construct some infrastructures in order to inhabit the area. They had two main problems: the lack of land for agriculture and the salty water.

The lack of land was solved with the use of “Chinampas” which was a system of a floating islands created by staking out the lake bed and then fencing in the rectangle with wattle. Then layered with mud, lake sediment, and decaying vegetation. To secure the chinampa trees were planted at the corners. The chinampas were separated by canals so canoes could pass through.

In this way Aztecs used all the features of the site to secure a very high agriculture production while treating its wastewater, creating a healthier living environment for all. At the same time this system provided room for a water based system of mobility.

The construction of the chinampas was possible thanks to a network of drainage dikes with double function and scales that retained and distributed painting: Tomas Filsinger the excess of water from the upper lakes

(Zumpango, Xaltocan, Xochimilco). The largest dikes were used to drain the area and also used as roads “calzadas”. The “calzadas” were built from east to west and from north to south. Those crossing the lake east-west had many bridges to let the water flow through. In contrast the north-south dikes were more robust with few opening and built to regulate water distribution and to separate the fresh from the salty water as well as to reduce floods during the rainy season.

This infrastructural elements permitted to connect the city of Tenochtitlan with the most important neighbouring cities forming a network, which supported with the navigation, was one of the main reasons Tenochtitlan became a powerful city for trade.

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Pre-colonial: The mountain and the alluvial plain During pre-colonial times, the mountain area of the basin was covered by dense forests; the lower slopes of inner valleys and part of plain lands were areas of high agricultural fertility. It is important to highlight that data from studies do not show any indication that pre-Spanish cultural practices have created a negative impact on forestry biotic communities; rather, their degradation starts after the conquest.

In the alluvial plain, where the water table was rather high, drainage was a serious problem. It was solved by means of the construction of gutters linked with the natural streams of the area. In those lands with a marked slope, erosion - which was a relevant problem-, was alleviated with retaining walls, banks, and terraces. In areas where water was available, a permanent irrigation system was established and many of the gorges allowed irrigation by flooding, which was a major solution to solve problems of frost, lack of rain and torrential streams.

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Colonial period After the conquest Mexico City (former Tenochtitlan) was rebuild according to the Spanish urban layout and European urban ideas.

The new ways of food production like animal raising, grazing, and tillage put under pressure the available land therefore the lake started to be reclaimed. In addition to the way of managing the land and natural resources many canals were blocked by the ruins of the ancient city and together both actions resulted in the drag of material that blocked the water flow in the basin.

This process was unnatural to the closed basin context and floodings started to happen more frequently. Thus, in 1607 the construction of the first canal started. Nochistongo canal redirected the stream from Cuautitlรกn River to that of Tula River.

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Independent period The fight against the lake nature kept during this period and a project by Francisco de Garay proposed to make a canal from the eastern part of the city’s center crossing the lakes of Texcoco and Zumpango and canalize the water streams in this route. In addition a system of secondary canals was proposed to collect and distribute the water excess from the lakes of Chalco and Xochimilco and to endow of a route for communication between Chalco and Zumpango. This canalization would function to drain, irrigate and transportation. However this project was never realized but is important to highlight the fact that the interest to work with the features of the landscape, namely the water, was there even though the tradition had been to fight it.

During this period the urbanization of the city was extremely important for the government.

With idealized ideas of architecture and urbanization layouts conceived in Europe Porfirio DĂ­az envisioned a modern city.

Boulevards were constructed and middle and upper economic class developments were built. The overexploitation of the springs caused that many more wells were necessary to provide the city with drinking water.

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Pos-revolution period After the revolution finished the construction of sewage system was a priority and based on the project by Francisco de Garay “el Gran Canal” (the great canal) was constructed. Nevertheless, the system of canals for irrigation and transportation was ignored and the canal was the only element realized to fulfil both the draining and the sewage.

Despite this huge “effort” to control water in the 1920’s decade the city was flooded again. In the 1950’s there were many huge floodings and the city had sunk because of the overexploitation of the aquifer. This caused the Gran Canal to lose its design slope and was necessary to start pumping the water.

In this time the rivers were already being used as sewage and started to become source of illness.

Besides as the city expanded new transportation was needed and therefore new infrastructure.

In 1938 an architect named Carlos Contreras proposed to pipe the rivers and transform them into roads (viaduct).

While the focus on the water management was to fight the threatening polluted water of the rivers and the lake, providing the city with drinking water was more difficult since the springs were a short source for the growing population. Therefore was necessary to make wells reaching up to 700 m depth.

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Second half of the 20th Century In the decades of the 1950’s to 1980’s the Federal District started a process of rapid growth thanks to the growing economy. This growth brought challenges to the process of urbanization in the Federal District and in the neighbouring municipalities of the state of Mexico.

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As the economy grew more people moved from small towns and country side around the whole country to the “big capital”. The projects of urbanization only focused on project a desired image of the city, therefore supported plans that boosted the growing of healthy areas to the south meanwhile people coming to the city in search of job, better health system or education tended to occupy the free areas around industrial settlements and decaying agriculture land, mainly in the north-west. This process of land occupancy was mainly illegal and irregular, and the people are known as “paracaidistas”. These irregular settlements/slums were lacking of services or infrastructure that soon was demanded and provided more for political interest during elections time than for planning purpose. Hence, built along rivers, flood and landslide prone areas, steep slopes of the drainage basins, neighborhoods faced constant damages.

Supplying drinking water to the whole urban area had become a major problem therefore a new water supply system was made: the system Lerma, which brings water from other basins, through series of pipes, dams and reservoirs, to Mexico City. In 1976 this system was already insufficient and a second system was built to support the existing. The system Lerma-Cutzamala now is 240 km long.

In 1952 the first viaduct (road on top of a river stream) was finished. This Viaduct named Miguel Alemán (in honor to that time elected president) was constructed on top of “El río de la Piedad”, one of the few streams that cross the city and discharge into Texcoco Lake. Twenty years later the first ring road was built. Like the viaduct Miguel Alemán, parts of this road were also built on top of rivers. In the coming years many more rivers were converted in viaducts to support transportation.

photography: from Legorreta, Jorge. 2009

As the population were growing plans for public transport started to be realized and in 1985 the master plan for the metropolitan subway was presented. However the plans only reached what later would become the central area of the city.

On the other hand when the Gran Canal was exceeded a system to support it was constructed: the deep sewage (drenaje profundo). The deep sewage is a network of 172 kilometres of huge pipes in a depth varying from 22 m to 217 m. This network of pipelines work during the rainy season to carry the excess of water, however there are indications that this system is also sinking.

photography: Fam. Guerrero http://tioloco-mexicodeayer.blogspot.mx

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Metropolitan expansion: the conquest of the mountain In 1985 Mexico City suffered a catastrophe: an earthquake of 8.1 Richter and the central area of the city collapsed. After this event, many people were relocated in the periphery and many more moved out of the center.

Central neighborhoods started to get empty.

In addition the suburbia dream was growing among middle and upper class and with a modification in the law of agricultural land ownership (before was forbidden to sell communal land) the land speculation started to grow. The expansion of the city reached and colonized the mountains to the west and the remaining agricultural land on the former lake to the east and to the north. The planned rich areas were supported by roads designed for private cars. On the other hand the unplanned informal settlements have been progressively provided with roads infrastructure, but not with a transportation system according to the needs of the population.

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Supplying drinking water is becoming more expensive and more difficult. Larger infrastructure projects are being developed to fulfil the demand. The transformation of the polluted rivers into viaducts continues. The sewage system and roads infrastructure are being “up-scaled� to secure safety against major flooding and cope with increasing mobility as the city sprawls.

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3.3 BLUE BROKEN HEART

photography: wikipedia.org

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The problem of water in the city: Providing water and wastewater service for the growing population of Mexico City is a big task.

Almost 73% of the city’s water supply is extracted from its aquifer, which is over-exploited since many decades ago. Ground water levels have been declining in the past hundred years, resulting in regional land subsidence which has lowered the city center an average of 7.5 meters. This subsidence increases the flood-prone conditions of the city and has damaged the infrastructure, including water and sewer lines. This situation leaves the aquifer and water distribution infrastructure vulnerable to contamination and to the population vulnerable to the risk of waste water inundation. All of this with the consequent risks to public health.

The physical capacity of the hydrologic system (and its processes) is the base for the sustainability of an urban water supply system and depends on: the vulnerability of the system to contamination; capabilities of the infrastructure for treatment, distribution, disposal and reuse; and the social, economic, and institutional aspects that influence the ability of society to manage its resources (National Research Council. 1995) Pollution of the rivers

Bottom right photography: Due to land subsidence some stairs have been built and attached to the Angel of Independence Column.

The height of the platform is the actual subsidence of the site.

Angel Borzelli; from http://abartraba.blogspot. nl/2010/03la-hora-delplaneta.html

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In the Valley of Mexico’s Basin primary streams contribute with 420 million m3/yr that could be used to supply water to the city (Legorreta, J. 2009. pp.

337). However, all the rivers were transformed into waste water sewage. The rivers that once fed the big lake now fed the large sewage system only to be sent to agricultural lands in the state of Hidalgo, which aquifer after many years of agricultural irrigation is now saturated and could use its own water resources (Blanca Jiménez C et al. 2004. pp.24) Moreover the way in which the foothills and mountain have been urbanized only increase the polluted street runoff to the rivers.

This simple transformation of a river into sewage has made evident the side effects of such action: Waste of water when it is crucial to use even the last drop

of it; The loss of potential for great natural public spaces, in a city where the average green public space is 1.5 m2/person (Gonzalez de León, T); Risks to public health; Damage to the ecosystem; Loss of the ecosystem services.

Overexploitation of the aquifer As was already stated almost 73% of the city’s water supply is extracted from its aquifer. In addition the continuous urbanization with permeable paving on streets and in the private area of the plots, and the urbanization of the infiltration zones in the mountains have caused that the aquifer is not recharged properly.

from other basins (Temascaltepec which is 200km away and 1000m below Mexico City).

This plan faces serious social, economic and environmental problems.

However, only the rivers contribute with 27 m3/s that are wasted in a mixed sewage (only 2.9 m3/s are used). In addition Mexico City produces 45 m3/s of waste water and only 6.5 m3/s is treated to reuse.

The overexploitation of the aquifer is considered 15m3/s. As consequence there is a regional land subsidence which main repercussions are: 37% of drinking water is lost due to leaks mainly as result of fractures due to subsidence.

In order to prevent floodings was necessary to build the deep sewer and expensive pumping systems. Because the subsidence continues and the deep sewer presents loss in the slope more of this investments are to be done.

Since the rain water is mixed with the waste water and during rainy season it is drained through the deep sewer, the risk of flooding with waste water is high. This could be a major environmental disaster.

Huge investments are necessary to level the subway system and it is expected to make major works in order to keep it working.

Shortage of water supply The current deficit in water supply in Mexico City is 5 m3/s, the overexploitation is 15 m3/s and in some years 5 m3/s are going to be needed. This results in a deficit of 25 m3/s. There are going on plans to bring water

photography: Angel Borzelli

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The problem of the suburbs in the drainage basins: Sources of ground water recharge in the basin are largely infiltrated precipitation and snow melt in the surrounding mountains and foothills to the west (Las Cruces Mountain range) and to the south (Ajusco mountaing range), which move as subsurface flow toward the lower elevations. Then the rivers collect the excess of water and carry it to the valley to feed the lacustrine environment.

However rapid growth over the past 50 years has been characterized both by planned urban and residential areas for the middle and upper class, and by unplanned and illegal land appropriations by immigrants to the peripheral areas, in this case the mountains and foothills in the western mountain range.

Torrential run off streams along steep streets which means safety risk to inhabitants and physical damage to natural spaces.

Constant risk of landslides which is a threat to the physical integrity of the population.

In addition to the environmental damage, the geomorphology of drainage basins and lack of planning defined the urban structure of the area and many times the social spatial distribution. This resulted in social contrasts

facing each other divided by the steep slopes and disconnected urban fabrics with problems of accessibility.

The slopes are now protected and it is almost impossible to build something there. However as rivers are still polluted they have become the utilitarian back yard for inhabitants which because the lack of waste collection services and proper information and education have turned the rivers into dumpsters.

Over time, government authorities have intervened in these irregular settlements to supply urban services, including water supply; although, the services remain inadequate for long periods of time. The interventions were mainly done to gain political support during elections. The environmental problems of urbanizing this area is worsen by those irregular settlements that occupied the gorges, river banks and floodplains, not only polluting the water course but also cutting down trees and destroying the whole ecosystem of the drainage basins. As result of this process ridges, slopes and gullies were urbanized in the same way as in flat land with no care for slopes or sensitive ecological areas. Only very steep slopes were left un-urbanized. Asphalt paving of earth roads were the priority during political campaigns resulting in four main problems: More runoff discharges to the lower lands which mean more water and pollution transported through the rivers.

Low infiltration rate which means low recovery of the aquifer that supplies water to the city.

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photography: Pablo Lopez Luz from imgur.com

The problem on the mountains: Las Cruces Mountain range lost almost 33 km2 of forest to agricultural, grazing and urban land between 1993 and 2002. Despite the extension of agricultural land in these mountains, the area is not as productive as other parts surrounding Mexico City. An important part of the agricultural land is not productive anymore and almost 40% of it is severely eroded.

Productive activities in the area have transformed the peripheral agricultural land to discontinuous urban-rural land use patterns; the transportation of goods, people and money has been intensified due to new transportation infrastructure (Escamilla Herrera I. et al. 2012) and nodes of development on the mountains. This certainly has brought benefits to the local population in terms of economic activities. However severe environmental damage threatens the entire metropolitan area.

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The current approach to fight the water related problems Currently there are plans and on-going works to increase the water supply capacity that include up-scaling the pipes and constructing a second system similar to the Lerma-Cutzamala to bring water from Temascaltepec which is 200 km away and 1000 m below Mexico City.

To fight the flooding risk the network of the deep sewer is being extended and soon either major levelling works of the tunnels or increasing the power of the pumping plants have to be done.

The largest waste water treatment facility in the country has been built in Hidalgo to treat all the waste water coming from Mexico City which is used for irrigation in Hidalgo.

These approaches are big centralized decisions that only take into account big monofunctional engineering infrastructures and leave other scales aside.

Another issue that arises is trying to limit further occupation of fragile or important environmental areas. The protection by prohibition is the adopted approach by government institutions. And in the case of gorges and rivers the result has not been encouraging as it was stated in the chapter P. of the suburbs in the drainage basins.

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photography: planverde.df.gob.mx

photography: from Legorreta, Jorge. 2009

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CONCLUSION

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In the beginning the territory of the Valley of Mexico, where nowadays is Mexico City, the city of Tenochtitlan was founded. This ancient city used the characteristics of the landscape of the former lake to form an urban structure and a regional network based on channels, calzadas (dikes-roads) and chinampas to blossom in an area where water prevailed and restrained urban development. With the passing time the synergy between human civilization and the natural environment that characterized Tenochtitlan changed and the features of the landscape were seen as threats rather than an ally. Soon the lake was drained; the rivers that crossed the valley were piped to make way for roads. As the city grew the valley was completely urbanized and the mountains surrounding it where conquered. Again the characteristics of the landscape were ignored and it brought major consequences for the city as we know it. In the valley water related problems such as drinking water shortage, river pollution, over exploitation of the aquifer, subsidence of the city and risk of flooding. In the mountains water related problems such as drinking water shortage, excess of running water in the rivers during rainy season and excess of runoff have direct impact on the valley problems. In addition, the geomorphological structure of

the mountains has defined the urban structure of the area. The lack of planning has fragmented the territory disconnecting the urban tissues of different drainage basins and making difficult mobility within the mountain and from/to it.

Therefore in Las Cruces Mountain Range (area under study) the following problems affect the living environment of the area and impact directly in the metropolitan area of Mexico City: Pollution of rivers due to sewage discharge.

Excess of water during rainy season & waste of rain water due to environmental decay of the open spaces and urbanization of sensitive natural areas.

Fragmented territory due to environmental and topographical conditions.

4.

Approach

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Ecosystem Services In the history of humanity the natural features of a place have been a main reason for human settlements to flourish and sometimes even to decay. As was shown in chapter 3.2 one reason for the Aztecs to thrive was the way they managed the natural features of the ancient lake; from food production to defensive infrastructure against enemy’s attacks. As human being developed new technologies to “control” nature and ways of exploitation of the ecosystem for food, energy production waste management among others issues, ecosystems stopped being considered as an integral part of our civilizations and we stopped taking care of it.

Even though in the late 1800’s concern on the loss of ecosystem capacities had been addressed was only in the second half of 1900’s when more attention started to arise. Many environmentalists and ecologists started to research on the topic and in 2005 The Millennium Ecosystem Assessment (MA) report defined Ecosystem services as benefits people obtain from ecosystems and is divided in four categories:

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Cultural services: “nonmaterial benefits people obtain from ecosystems through spiritual enrichment, cognitive development, reflection, recreation, and aesthetic experiences”(ibid.)

The concept of ecosystems services, even though sometimes is an abstract concept for recognition, it has become an important discourse for linking the functioning of ecosystems to human welfare.

Nowadays this is not only argued by ecologists and planners. An example is that the United States President’s Committee of Advisors on Science and Technology (PCAST), and the World Bank have recognized and expressed concerns and recommendations regarding the economic perspective of the ecosystem services (Dasgupta, P. et al. 2000).

Supporting services: ecosystem services “that are necessary for the production of all other ecosystem services” (MA. 2005)

In this report I will focus on the hydrological services which are related to the preservation of hydrological basins and the role that land uses and land conservation practices to maintain the quantity and quality of water.

These services are the following:

Provisioning services: “products obtained from ecosystems” (ibid.)

Providing; Source of drinking water, irrigation and industrial production.

Regulating services: “benefits obtained from the regulation of ecosystem processes”(ibid.)

Regulation; Drainage basins are fundamental for the hydrological cycle of the valley since

it is the main source of water for lakes and recharge of the aquifer. Thanks to this cycle soil fertility is constantly renovated and erosion is prevented. Wetlands and floodplains decrease torrential streams reducing landslides and flooding damages besides retaining water for dry seasons. Drainage basins offer natural qualities that support species habitat and therefore genetic diversity.

Cultural; Drainage basins support recreational activities which at the same time can support economic activities, besides the aesthetic and psychological benefits.

Furthermore it is important to highlight the importance of the ecosystem in recovering or improving social conditions as Dasgupta, P et al. (2000) address; “environmental problems go beyond those that are aired during international negotiations; there are myriad local environmental problems in constant need of attention by local people.” Therefore engaging community in the process of ecosystem remediation is of high importance.

This process of engaging should be addressed as contribution to start new social dynamics which result in social cohesion.

Landscape Infrastructure

Tools and models

Another important recognition is that ecosystems are highly influenced by human activities supported by infrastructure which can be defined as “the basic facilities, services and installations needed for the functioning of a community or society” (Webster’s Unabridged Dictionary. 2009, in Hung, Ying-Yu et al. 2011). As the infrastructure comes before and as a mean to the realization of human activities these man-made systems have the power to define not only the structure of the city, but the structure of the natural areas which affect directly its processes and capability to provide benefits to people.

Due to the geo-morphological structure of the mountain, in the area under study the roads and the rivers are placed in parallel positions and organize the area.

Therefore infrastructure has been reconceptualized from a centralized, singlepurpose system to control nature into a manmade landscape system able to work in synergy with the ecosystem services and support not only economical and productive human activities but provide for social and ecological benefits as well.

On one hand the roads that run climbing the ridges of drainage basins making the urban areas accessible and as the lively desired front. On the other hand the rivers which are open sewers are the hidden and denied dirty backyard in the lower parts. In between, there are abandoned inaccessible open spaces of different scales which need to be ecologically regenerated to accomplish its natural role in the hydrological system of the drainage basin.

“The backyard” all those polluted rivers and abandoned slopes need to be transformed from sewer infrastructure to corridors with the capability to carry “good conditions”*1.

Therefore the concept of landscape as infrastructure is useful to change the current conditions of the rivers in the framework of ecological regeneration to provide, improve and support social and economic benefits in the area.

*1: “good conditions” as described by Tjallingii (1996) is the potential synergy between ecology and human activities or the way I see it the synergism between ecosystem and human activities.

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Geo-morphological conditions parallel infrastructures

Roads climb the mountain following the ridge lines making urbanization along them more suited for development, while the rivers remain as open sewer creating a two way risk condition population vs infrastructure.

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Multiple Use Module as node For this purpose, the Multiple Use Modules (MUM; Harris 1984, in Larry D. Harris et al. 1986) is a tool that can be used to organize this corridor.

A Multiple Use Module consists of “inviolable or well-protected core areas surrounded by buffer zones of centrifugally increasing utilization by man. Buffer zones encompass multiple uses of appropriate type, scale, and intensity for each node.� (Larry D. Harris et al. 1986).

When MUM’s are distributed along ecological corridors, give the potential to those valuable natural areas to work as high-quality nodes of diversity in a larger whole. In addition the concept is multi-scalar and can be applied from a whole region to local communities or a single managed area (ibid.).

However MUMs under the perspective of this study, are not areas for protection from urbanization but rather areas for interaction between the landscape system and the urban needs.

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Multiple Use Module as corridor MUMs under the perspective of this study, are not areas for protection from urbanization but rather areas for interaction between the landscape system (ecosystem services) and human needs.

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MUM’s can buffer linear infrastructural elements causing disruption in ecological sensitive areas

Transit Oriented Development Node

In order to organize the front area (roads) to support the system of the drainage basin the model of Transit Oriented Development will be used.

Although Transit Oriented Development (TOD) is a model highly related to mobility, accessibility and urbanization, it is used to preserve and maintain natural areas important for ecological functions, in advance of new development or to retrofit existing ones (Anthony Walmsley, 2005)*2. TOD is a way to organize growth around city and regional transit systems. It is a model of organization based on public transit corridors and nodes. The nodes are centres called “Pedestrian Pockets� with transit stations or stops, around which high density and mixed of uses is fostered and progressively lowerdensity development spreading outward from the center (ibid.)

*2: As was explained, planned and unplanned sprawled urban expansion to the natural areas of the mountain has resulted in the loss of natural open spaces which have increased torrential run-off. This situation increases the amount of water that the sewage system of the city has to deal with. In addition less surface is available for water infiltration and recharge of the aquifer.

progressively lower-density development spreading outward from the center

e nc ta m s i d 0 le 80 ab k m al w 400

Transit stop Core: commercial, industrial, high density

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Transit Oriented Development Corridor

The three main principles of TOD are the “Three D’s�: Density of residents and jobs near transit stations; Diversity of land uses (residential, commercial) near stations; and Design, i.e. urban design elements that make the station more integrated with the surrounding area and more accessible to pedestrians and bicyclists.

(Bernick, M. and Cervero, R (1997) in Michael Gilat and Joseph M. Sussman. 2002).

In the developing world, where cities are growing rapidly and car ownership is still low, TOD provides an opportunity to design the urban form to be transit-oriented. Lowincome people can thus be served by cheaper high capacity transit, spend less of their income on transportation and have better access to jobs. They will make fewer and shorter trips by informal low capacity transit, reducing congestion and pollution. In the long term, TOD may slow down motorization and mitigate its effects.

(Michael Gilat and Joseph M. Sussman. 2002).

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Transportation infrastructure and rivers parallel infrastructures

Both models use nodes, corridors and networks as main elements for organization. While TOD organizes urban growth around nodes, MUMs organize urbanization around landscape areas.

If a TOD model for further (re)development/ improvement of the area were to be used: How could the landscape system of the drainage basin relate to the TOD approach? Is it possible for a transit network and the landscape system to support each other and together become the trigger for the improvement of the area? Given the spatial structure defined by the drainage basins, gullies and rivers how to organize the different human and ecological flows of needs?

This approach will be further discussed by understanding transit and open water corridors in the city and in relation to the area. The discussion will address the importance of both to form a framework that contributes to solve the water related problems of the city, at the same time functioning as backbone for improving the living environment in Las Cruces Mountain Range.

Due to the geo-morphological structure of the mountain the two infrastructures are placed in parallel positions acting, on one hand the roads as the lively desired front and on the other hand, the rivers/sewer as the hidden and denied dirty backyard.

The hypothesis of the two corridors (rivers and roads) as backbone for the drainage basins will be further investigated and tested in one river as case study to explore the potential of this spatial organization.

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The roads as the desired front parallel infrastructures

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The rivers as the dirty backyard

parallel infrastructures

photography: from Legorreta, Jorge. 2009

Organizing the corridors

THE BACK YARD Landscape Infrastructure

THE FRONT Transit Oriented Development

Transport Oriented Development and MUMs use nodes, corridors and networks as main elements for organization. While TOD organizes urban growth around nodes, MUMs organize urbanization around protected areas.

This would work as framework to approach the transformation of the backyard.

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5.

Hondo river

Mexico City faces many water related problems; water shortage, over exploitation of the aquifer, low quality and polluted water and waste water flood risk. The future growth and stability depends on whether those problems can be solved. One major problem in the area of “las Cruces” mountain range is the pollution of the rivers with the consequent abandonment and environmental detriment of the surrounding spaces in their drainage basins. The river is a natural element with the capability of providing many ecosystem services, from providing water for irrigation of agricultural land, regulate temperature creating micro climates and cultural as safe places for recreational and other social activities. However nowadays the rivers are treated as the ugly backyards, rivers are just sewers.

To restore the rivers and their territory it is important to address the ecology, the society and the economy as a triad of interconnected flows. The river and the drainage basin will be addressed as the backbone for the reactivation of the triad.

Features In the area of “las Cruces” mountain range there are 18 rivers with similar characteristics (physical, social and uses around them).

Hence understanding one river can help as framework for future phase interventions in the rest in a progressive metropolitan strategy.

Hondo river is the one that shares the most characteristics with the rest; therefore this is the one to be investigated.

Hondo river is 21 km long and runs through two municipalities of the State of Mexico – Huixquilucan and Naucalpan -. Its origin is at 2.500 masl with water supplied from four branches and one spring. Just before entering the city another branch joins, Río Borracho. Once entered the city the urban area is in process of consolidation and leftover open spaces are still present. In this area there is a detention basin to prevent overflowing of the river during rainy season. Once in the municipality of Naucalpan urbanization becomes dense and sewage is discharged into the stream.

Three more tributaries join Río Hondo: Río Sordo, Río los Cuartos and Río Tololica. The stream continues in form of a channel until Cristo detention basin which discharges to the western deep sewer or the central deep sewer to be pumped 60km to the north of the city into a dam in the State of Hidalgo.

Río Hondo can be typified in three main stretches: Rural, Transition and Urban.

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Hondo river in Mexico City

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Hondo river and the 18 rivers in las Cruces Mountain Range

RĂ­o Hondo

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conditions of the river in different areas

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Metropolitan sewage

Deep sewage Polluted river Former lake

City center

Rivers are part of the sewage system of the metropolitan area.

Because of this situation, their contribution to the hydraulic balance of the basin is not useful.

However with its 23 m3/s contribution rate, it is a burden to the already saturated sewage system of the city.

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Hydrology

More than half of Hondo river remains with large open spaces. It is precisely the area in which the amount of rainfall is higher.

However those open spaces are mostly eroded and deforested. Therefore regenerating them is important to reduce excess of run off and torrential streams, that until now have to be fought down in the city.

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The river is polluted from the upper parts of the mountain making difficult its use in the rest of the stream either for provisioning water for human or irrigation use or for ecological purposes.

Open spaces

The regeneration of eroded, deforested and unproductive land most take into account social needs and therefore community must be engaged from the beginning of the process.

In addition the regeneration strategy must cope with ecological problems and social issues creating a synergy between both.

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Natural - channelized

The physical conditions of the river vary along its length. However most of it has been affected by human actions to control the stream or just by informal works.

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The affectations to the river banks and floodplains only have caused more torrential streams and landslide prone areas, not only leaving under risk inhabited areas but also making more difficult to cope with the excess of water during rainy season.

Roads+public transport+major metropolitan centralities

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Roads-public transport-uses

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Socio-economic

Ecological and urban regeneration of the drainage basin and the river is not a matter of socio-economic classes interaction. It is a matter of creating good conditions that can result in community engagement to the long term livability of the area. Schools, social and ecology organizations and government actors must act together with the local community.

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Crossings

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Zones Rural

main road

Transition

underground station

underground line- to center and south of the city

underground line- to westsouth of the city

underground line- to east of the city

Urban

CBD, commerce, services industry

park

seasonal agriculture forest

education

eroded land/ brownfield

road river road

road road road road

road

river

river

river river

road

road

river

river

road

road

road river road

sewage retention basin

road road

road

Rual

Transition

Urban

road river road

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Rural: The rural area is a low population density and XL open spaces in mixture of patches of forest, agricultural land and induced grassland. Due to the lack of irrigation system agriculture is a seasonal activity and even though it still supplies food for the local community and some surplus that can be traded, the rural area is characterized by abandonment of agriculture as main activity. This tendency has left the land deforested, eroded and unproductive contributing to increase run off during rainy season (June to September) which further down the river means torrential streams and more water in the sewer system of the city with the consequent risk of flooding. The borders between forest and agricultural patches are the most productive and are in constant pressure of further deforestation, situation which leads into a vicious circle of deforestation, erosion, low production and more run off into the rivers. The valleys along rivers are wide and remain as open space with some seasonal agriculture activity. Despite the conditions of the river in the urbanized areas are natural, the banks have been affected and result in unstable and eroded areas. The river is used as sewer with punctual black water discharges. 97% of homes are provided with sewage and drinking water services.

road road

1-mixture of patches of forest, agricultural 2- deforested, eroded and unproductive land 3-seasonal agriculture supplies food for the local community and land and induced grassland some surplus that can be traded

river

river

river

road road

1

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Rual P.

2

4

3

4-river banks have been affected and result in unstable and eroded areas

Transition: The transition area is characterized by the process of rapid urban consolidation pressing the remaining open natural spaces. The governmental attempts to protect them (especially from poor people) forbidding any activity in those remaining areas only have led to the abandonment and detriment of the natural open spaces which are mostly deforested and eroded. Despite the existence of large open areas, accessible green or public spaces are few. The valley is narrow, the banks of the river in some stretches are natural but unstable in other stretches have been stabilized with stonework. The river is used as sewer with punctual black water discharges.

The Urbanization is mainly located along the roads on the ridges. Population is a differentiated mixture of poor and rich (50% earn less than 490 e/monthly 4-5 family members).

While high-income population tend to live in gated neighborhoods with sports facilities and amenities and access to private higher education institutions, neighborhoods of low-income population lack of educational facilities other than the primary and secondary school (6 + 3 years education). Public parks, sport centres, community facilities and job centres are few or inexistent. These conditions increase the metropolitan mobility rates and distance. However means of transport are deficient provided by van vehicles. Private car is supported over public transport even though less than 17% of population in the area own or is capable to buy one. As result the low-income group of society, which in the area are 50% of the population, is in disadvantage and marginalization.

4- poor population = 50% 5-high income gated communities with lack of educational & community’s facilities, sports facilities, amenities and access to public parks, sport centres, job centers private higher education institutions

1-protecction by forbidding have resulted in abandonment and detriment of natural open spaces main road

seasonal agriculture forest

underground station

underground line- to center and south of the city

2-affected river banks remain 3-punctual sewage discharge natural but unstable and eroded

underground line- to westsouth of the city

underground line- to east of the city

CBD, commerce, services industry

park education

6- support to private car vs inefficient public transport resulting in disadvantage and marginalization for the low income group of society

eroded land/ brownfield

Transition

1

3

2

6

4

4

5

6

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Urban: More than half of the length of Río Hondo is in a dense urban environment. There are very few open spaces and those remaining are small or private. Ridges, valley and gorges have been completely urbanized. The water is severely polluted due to the use of the stream as sewer starting in the rural area up the mountain. The whole length of this part of the river is channelized but the conditions are different. In some stretches the river has been completely channelized with concrete, some parts are channelized with stone work and others remain natural but unstable.

The socio-economic conditions along the river vary, but still almost 50% of the population is poor or lower mid-class. Even though some areas along the river are not accessible due to the lack of proper urbanization, large part of the services and urban facilities in the area such as schools, medical centres, markets and playgrounds are located next to the rivers. Public transport is provided by a combination of micro-buses and van vehicles that run through the main roads on the ridges. At the end of the river there is the large detention basin “El Cristo” considered by the municipality of Naucalpan as place of environmental contingency because all the waste water of the west of Mexico City is discharged in this place to be pumped out of the city.

2-natural and unstable

3-stone work

4-concrete

5-Even though some areas along the rive are not accessible due to the lack of proper urbanization many services and urban facilities are next to it 1-Ridges, valley and gorges have been completely urbanized

parts of the river have been channelized with concrete, some parts are channelized with stone work and others remain natural but unstable

6-detention basin “El Cristo” is a place of environmental concon tingency because all the waste water of the west of Mexico City is discharged in this place to be pumped out of the city

road river road

road

road

road

road

river

river

road

road

2

5

3

1

road river road

sewage retention basin

road river road

4

6

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Urban

6.

Strategy

VISION

STRATEGY

To transform drainage basins in a system that recognizes the morphological features and the ecosystem services of the landscape in order to organize, connect and articulate the urban and natural territory of the mountain with the city in the valley sewing together the metropolitan territory.

The strategy addresses the problems of pollution of rivers, excess of water and fragmented territory due to topographical conditions using the current situation in which due to the geomorphological structure of the mountain, the roads infrastructure follow the ridges and the rivers in the lower areas are placed in parallel positions, to organize the two corridors supporting different but complementary activities and to link them with the open spaces in between.

The rivers will become ecological sound corridors of water, parks and gardens that support and serve urbanization by triggering outdoor activities and sports, supporting social facilities and productive public space which can benefit ecology and society and result in economic improvement from the family core (bottom up – spontaneous organization) to large metropolitan investments (top down – planned strategic interventions); The roads on the ridges will become metropolitan corridors guiding urbanization on the mountains and connecting it with the valley. The spaces in between the corridors will act as buffer not to protect the ecological corridor but to boost interaction between the natural and urban systems.

The strategy will be based in two principles to be tested in 4 strategic interventions along Hondo river. The aim is to explore its potential in different landscape and urban conditions.

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Rivers and roads as organizing corridors Rivers organize a landscape system (LS) that target water related problems of the area and support ecological and social functions by decentralizing water management infrastructures of sewage, drainage and flood control integrating them into an accessible landscape. The actions to be taken are: Regenerate the natural banks and floodplains of the river and naturalization of the channelized stretches.

Creation of storage ponds/parks to control and store excess of rain water, based on the amount of rainfall, possibilities of the topography and proximity to urban areas.

Separation of sewage from the river, by collecting and treating waste water in constructed wetlands before discharge in the river.

Make accessible these areas to support recreational, educational and productive activities.

The interventions are used to create regional and local public space, to support local social facilities and slow mobility corridors which are connected to transit stops supporting local mobility and metropolitan recreational activities.

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These actions reintroduce biodiversity, biotic exchanges and new ecotones, transitional habitats for animals and vegetation creating a new landscape.

Furthermore it creates diversity in the living

environment and public spaces along a corridor with different stretches and patches within the social landscape that can trigger new activities and support local economy.

Roads on the ridges carry larger functions related to metropolitan accessibility such as Hospitals, offices, universities, new housing projects, shopping malls, etc. With expected population growth by 2020 of more than 450 000 inhabitants (almost The Hague in The Netherlands or Terrassa + Sabadell together in Catalonia) in the urban area of Las Cruces Mountain range, roads will guide redevelopment of urban areas (rather than using natural areas) for future growth in pedestrian pockets served by Rapid Transit Systems such as Bus Rapid Transit (BRT), TRAM and Light Rail (LR) that connect the area of the mountain with the center of the city and with CABLE CARS different sides of drainage basins with each other making use of the open spaces left along the main power lines that cross the mountain range.

Landscape system (LS)

slow down, collect, store and treat water

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Landscape system (LS)

regeneration of banks & naturalization of embankments

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Regeneration of the natural banks and floodplains of the river

Naturalization of the channelized stretches

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Landscape system (LS) collect & store: ponds/parks

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Storage ponds to control and store excess of rain water, functions as parks and are located based on the amount of rainfall, possibilities of the topography and proximity to urban areas.

current

rainfall, hidrology, topography and urban areas

proposed: storage pond/ retention basin as park

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Landscape system (LS)

collect & treat: constructed wetlands/parks

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The ecosystem services provided by wetlands are used to collect, separate and treat sewage before discharging into the river through a system of subsurface flow and free flow constructed wetlands and floating islands.

In addition, some parts of the wetlands can be recreational routes that support slow mobility as well as educational activities.

current

proposed: constructed wetland as didactic/recreational park

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potential activities Sports center

Community’s center

1

2

Park / Camping

Agro-park

3

Seasonal park

4

1 2 3

4

5

6

5

7

8

9

E E

A

D

A B D

B

B

A E D

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A - Linear wetland

B

E

B - Wetland basin

B

C

E

E

E A

A

C - Retention basin D - Storage pond

E - Bike / pedestrian path

potential activities Community’s center

Youth’s center

6

7

Training center

Community’s center

8

9

1 2 3

4

5

6

7

8

9

E E

A

D

A B D

B

B

A E D

A - Linear wetland

B

E

B - Wetland basin

B

C

C - Retention basin D - Storage pond

E

E

E A

A

E - Bike / pedestrian path

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roads corridors

Current situation

connecting the mountain with the valley guiding future growth to reduce urbanization of open spaces Offices

Concept

Shops Restaurants Library Day care Hospital Bank Gym

CBD industry health/ services private car based main roads main ring road

transit stop/station

Public transport is developed inside Roads on the ridges served by the main ring road the rest of transport Rapid Transit Systems connect the infrastructure is private car based roads mountain with the city center

pedestrian pocket

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transit stop

underground stop/ line

TRAM

Cable car stop extension

Bike/ pedestrian path

CBD, commerce services

Cable cars connect different sides of drainage basins using the open spaces left along the power lines

Industry

Park

Educational

public space

high density and mix of uses

PEDESTRIAN POCKETS (PP) along roads will guide redevelopment of urban areas for future growth

Social facility

re-development/ future growth

Scales of mobility

Slow/local mobility + fast/metropolitan mobility RIVER + RIDGES: integration of the corridors

inter modal node (bike friendly)

new social facility (bike friendly)

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Open space as interface (OSI)

Reclaim, recover and regenerate the open spaces along the river between the built up and the stream to be used as interface for the interaction between human activities and the natural flows and processes of the drainage basin.

On one hand, by making accessible reclaimed and recovered open spaces and regenerating them with focus in social needs such as public space (recreational public parks) and productive public space (agroparks) can be used to engage community in caring the open space by actually making it. In the long term this action can result in the preservation of the environmental qualities of the place strongly attached to the sense of identity of the community.

On the other hand by making accessible these places can work to consolidate or create new flows, connecting in the local scale both sides of drainage basins which currently are spatially and many times socially disconnected.

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current situation of open spaces

open space as interface (OSI) reclaim, recover & regenerate

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open space as interface (OSI) reclaim, recover & regenerate

current

current

proposed Proposed: Agropark as a place to regenerate the slopes and engage community in this process caring the open space by actually making it.

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Agroforestry as strategy to reforest (reduce run off) and make productive the land again (improve economic conditions of people and guarding open space).

Making accessible the open spaces can consolidate or create new flows, connecting in the local scale both sides of drainage basins : CONNECTING the pre-existing, facilities, society, flows, nature. BOOSTING new flows & activities.

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Strategy

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7.

Design tests

The following four design tests where selected sites due to the different landscape and urban conditions which represent typical existing situations on the rest of the territory of the mountain. In this way the exploration of the potentials of the principles of the strategy can be tested as sub-case studies and then replicated to form new systems on other drainage basins.

The first site is a rural setting in the higher part of the mountain and deal with the loss of agriculture because there is lack of water for irrigation during dry season. However it is a paradox since it is the area where most rain falls. The second site is a transition area in process of urbanization just the way that was stated in the chapter 3.3 bringing more ecological and urban problems to the living environment. The third site is a spot where urbanization, topography and pollution of the river have torn apart the urban fabric and explores the potential to be transformed in a node to different scales of the city and Hondo’s river drainage basin.

Finally the fourth site is a large sewage retention basin which is the end of Hondo river stream in the valley. It is an environmental contingency site but located in a place where its also a metropolitan barrier.

Through the principles of the strategy the four cases are going to be explored in order to present possible spatial results.

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Huixquilucan de Degollado

7.1 Rural

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Due to deforestation the mountain has lost its capability of providing efficiently its ecosystem services directly related with water such as, water retention that keeps moisture in the soil making land fertile. With the loss of fertility in the lower parts of the mountain and the pressure for urbanization, farmers opted to sell lower lands and start farming higher lands. The process continued and agriculture is almost inexistent as an economic activity in the area. What is left is a void in the forest of unproductive and ecologically degraded deforested land.

This situation makes worse the problem of the sewer system in the city because more water runoff from the mountains flow down to the city. Right now one of the reasons agriculture is not an option for the rural communities is the lack of water for irrigation, which is a paradox because in the area the annual rainfall is 1000mm. Only the basin in which is settled this rural town catches 13 million m3, which is the half of the total water needed to fill the lake Nabor Carrillo. However this large amount of water flows through the river mixed with the sewage first in the rural area then in the city.

The town is structured in three main programmatic strips; The agricultural area on the slope to the north, the valley where Hondo river flows and the built up core in the southern top.

The approach of the project is to consolidate these areas paying focus on the central valley and the structure linking the public facilities and recreational public space adding a landscape system to store the “excess� of rain water to irrigate the agricultural fields and provide water for the aquaponics park. Recreational, social and training facilities will interact the landscape system and future urbanization to retrofit each other.

Huixquilucan de Degollado

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(A) Scale of Nabor Carrillo lake (red) in relation with the city.

A

B

(B) Scale of Nabor Carrillo lake (full & half size) in relation with the site.

3

1 2 4

1

3 93

P.

Dry season

Affected banks of the river & sports fields as left overs of former agricultural land.

2

Rainy season

Topography & main run off

0 +20 Lower

+60 built up core

Roads

+300 primary Higher run off

Rain is the main natural source of water in this area, therefore primary run off and topography defined the areas for the basic activities of the town which are agriculture and a built up core. In the beginning the valley and the slight slope to the north were used as agricultural area. The top of the southern side of the basin which slope is very light has evolved mainly into the built up core of the town.

road

Roads & program strips

main road

The agricultural origin of the town can be seen in its own structure. The agricultural area on the slightest slope of the site to the north is crossed by two parallel roads that provide accessibility and are connected to the system of highways to the industrial areas of Mexico City and Toluca city.

forest

seasonal sports agriculture fields

built up

services

With the loss of agriculture and the structure of the roads the area is now organized in three main programmatic strips: The agricultural on the slope to the north, the valley where Hondo river flows and the built up core in the southern top.

P.

94

Agricultural

Social domain?

Urban

1

2

forest

seasonal sports agriculture fields

built up

services

The agricultural area has been constantly under pressure from urbanization. The area on the top right (1) is completely urbanized while the area to the left is in process of urbanization.

95

P.

forest

seasonal sports agriculture fields

built up

services

Now, a large part of that agricultural area in the valley is used as football fields, one bull arena, sports fields and a school, all along the river. This shows how unimportant agriculture has become to the town, but at the same time how important is the river in structuring public space and public facilities and as a tool to preserve open spaces.

Despite these activities are mainly suited for open spaces, large part of the area along the river are left overs of former agricultural land that piece by piece is being urbanized along the road. This is transforming the river in that denied backyard.

built up road

main road

The gorge as a physical limit defines the start of the urbanized core on one flat ridge.

exploration

P.

96

LEFTOVER

97

P.

BACKBONE

Landscape system

agroforestry

Landscape system

storage pond

primary run off

A system of storage ponds collect the rain water from the principal run off to be used for irrigation all year long.

Agroforestry is introduced by training people in a research center in the area. This agriculture and forestry technic can help to recover agriculture as a main activity and preserve the water related ecosystem capabilities of the mountain.

storage pond

aquaponics park

Open space as interface

primary run off

The surplus of water is collected by storage ponds along the river that provides water for a new aquaponics park, irrigation for open spaces in the valley, recreational activities and to maintain a constant stream in the river.

path new social camping bike/pedestrian facility site

agropark

The open space in the valley function as buffer from the built up areas on both sides of the river. It also is the area where social facilities based on open spaces will be located such as an agropark, a research and training center in agroforestry, urban agriculture and aquaponics, a camping site with different recreational and leisure activities targeting not only local community but regional users and a business incubator that will link the local production with the urban economy in the city.

P.

98

Roads corridors

3

1

2 path road bike/pedestrian

BRT

stop

The TOD will organize the transportation system with a BRT and three stops. Two serve existing built up areas (2 & 3), and a third one (1) will accommodate future growth in a pedestrian pocket in the existing area in process of urbanization.

99

P.

P.

100

current

101 P.

proposed

Huixquilucan

7.2 Transition

P.

102

This is an urban area in process of consolidation. On one side of the river there is a poor neighborhood, on the other side there is a high income gated one.

The Poor neighborhoods in the area lack of proper social facilities which can help to improve their socioeconomic conditions. In addition the existence of non-functional large open spaces in the valley and slopes of the drainage basin results in a visible and dramatic spatial segregation of both groups.

The intervention won’t address the river and open spaces only as a place for interaction between the two groups. Rather it will be the space that links the built up with the natural processes of the drainage basin by regenerating open spaces and engaging community in this process. New social facilities and open spaces will improve social and environmental conditions of the area. Only in the long term with the ecological, spatial and social transformation, segregation can decrease.

Huixquilucan de Degollado

Huixquilucan

103 P.

The problems in the area related to pollution of rivers and excess of water are the following: Pollution of rivers due to discharge of sewage into the stream in specific points.

Large areas of deforested and eroded land which together with steep streets increase torrential runoff.

In order to protect the remaining open spaces of the drainage basin government forbid the access to those areas resulting in the abandonment and ecological decay of open spaces in addition to the creation of a border that difficult current and potential flows to different sides of the drainage basin.

1 2

3 4

1

3

Sewage discharge into the river

2

4

Polluted river & affected banks

Steep streets (3) in addition to deforested & P. eroded 104 land (4) contribute to excess of run off

Protection of open spaces by forbidding access only has led to abandonment of land and creation of a border obstructing current flows and limiting potential ones

7 5

6

8

5

7 105 P.

Informal path to cross the valley

Open space along one power line & unpaved/informal streets

6

8

Unpaved streets & informal paths

Agriculture in the border shows how people try to make use of open space to fulfil their own needs

Topography

0 +20 Lower

Sewage discharges

+60

+100

+140 Higher

main sewer

Main roads

sewage discharge

main road

Just like the main roads, the main sewer follows the ridge of the drainage basin and discharges down the foothills.

The longer the sewer is the more sewage is carried and discharged in the valley. Why not using the large open space in the area to hold and treat it?

P.

106

Urban facilities and services

built up

multifamily facilityhousing services

Street run off

main road

Urban facilities and services are located along the main roads while the open space is denied for any kind of activity.

107 P.

street

Slope open space conditions

main run off

Steep asphalt streets are like channels that carry torrential run off.

forest

deforested/ eroded

In addition to the steep streets, deforested and eroded land contribute to excess of run off which downstream results in an overloaded river.

Socio-economic

Border condition

Section border condition

4 road

high income

low income

The high income neighborhood is allowed to occupy the slope of the drainage basin because its urban morphology leaves a large amount of open spaces. This reveals that then it is a matter of open space amount not a matter of using the open space.

built up

border

100 - 900m

road

flow

River pollution, deforested and eroded open spaces protected by prohibiting activities in them and topography create a border condition which leaves the drainage basin’s slope without ecological or social function.

P.

108

BARRIER

109 P.

BACKBONE

exploration

P.

110

In Mexico City urban agriculture has been a tradition since pre-Hispanic times. Nowadays is common to find small crops and vegetable gardens in the houses of areas like this one. Even livestock of small animals like chickens, pigs, goats and rabbits. For this reason and according to the principles of the strategy an urban - agropark is proposed as backbone for the environmental and social regeneration . The Agropark has four main zones to be developed in phases: The water system, a linear park, the social activities core, community’s garden.

Landscape system: Bike/pedestrian paths

Landscape system: Retention basins/storage ponds & constructed wetlands

retention basin/ park

constructed wetland-basin

constructed wetland-channel

built up

bike/pedestrian path

Landscape system: Section

public bike/ bike parking

The water system is formed by the regenerated banks of the river, a system of retention basins, storage ponds and wetlands that collect, separate and treat the local sewage before store it for irrigation of the park or to be discharged into the river to guarantee a constant stream in dry season. Part of the power line’s space is used to collect the waste water from the main sewer on the ridge and treat it through a series of terraced constructed wetlands.

In addition this water system support recreational and education activities. The higher parts of the banks are used for pedestrian and bike paths that connect the area with the lower urban part of Rio Hondo’s drainage basin where larger social and public facilities are located (between 3,5 km and 10 km). The forest will provide space for rain gardens and a natural area as buffer between the community’s garden and the banks of the river.

111 P.

The wetland system collect, separate and treat the local sewage before store it for irrigation of the park or to be discharged into the river Huixquilucan and Main centralities along Hondo river

3,5 6 10km

Open space as interface: Linear park

built up

linear park

Open space as interface: Community’s garden

bike/pedestrian public bike/ path bike parking

The linear park is used as first interface with playgrounds, picnic areas, new vegetation, rain gardens, paths, information and access points. Its purpose is to make porous the current border for gradually reclaim and regenerate the open spaces.

community’s garden

urban agriculture

Open space as interface: improved accessibility

new facility

Sports facilities and the community center are integral part of the social core. The community center will train people in urban agriculture with special focus on regenerating and maintaining the open spaces. The community’s garden will provide space for livestock and community farming as well as areas for future schools and new reforested areas with rain gardens and playgrounds that will reduce urban runoff and stabilize landslide risk areas.

cable car

cable car new bike/pedes- public bike/ stop stairway trian path bike parking

The inclusion of new stairs, bike and pedestrian paths, elevators, escalators and a cable car system not only endow of accessibility to the recovered open spaces but improve connectivity across different sides of the drainage basin, which improve and support existing or new flows.

P.

112

Roads corridors: TOD pedestrian pockets

TOD pedestrian pockets + Landscape system

TOD pedestrian pockets + Landscape system connecting different drainage basins

connecting landscape

built up

multifamily facilityhousing services

cable car BRT pedestrian stop stop street

TOD pedestrian pockets are located according and in relation to existing vacant land or brown fields and current local centralities.

113 P.

bio swale/ rain garden new tree lined street

The pedestrian based streets where most run off flows are transformed into bioswales, rain gardens and tree lined streets, which will form a continuous green space that connects transversely different drainage basins improving pedestrian and landscape connectivity as well as reducing torrential urban run-off and urban island heat effect.

connecting people

TOD pedestrian pockets + Landscape system: Pedestrian based street as bioswale/rain garden

current

proposed

This new relation between the landscape and the built up area open new possibilities to transform the living environment and support the redevelopment of areas into pedestrian pockets (high population density, local commercial, social and cultural activities, and well connected to metropolitan centralities by public transport) boosting new activities.

These actions will require cooperation among different actors and stakeholders; Government, social organizations and schools will have an active role in engaging community to regenerate the open spaces. This is by understanding new public space as a social and ecological asset and not only as a right.

P.

114

115 P.

Current

P.

116

117 P.

Proposed

6 pedestrian pocket

5

1

2

3

4

5

6 pedestrian pocket

P.

118

119 P.

current

current

Drainage basin

from dirty and denied back yard to backbone for improving the living environment

6

6 5

5 4

5 linear park

open space as interface

1 river

2 retention basin/storage pond

landscape system

3 constructed wetland

4 agropark

5 linear park

open space as interface P.

120

121 P.

Naucalpan south

7.3 Urban

P.

122

Huixquilucan de Degollado Naucalpan South Huixquilucan

123 P.

The site is a spot where the main road coming from the industrial area in the valley and connected to the rest of the city through the underground line to the center and the south, distributes transit to different urban areas/drainage basins.

In this spot of distribution the topography, the river and two large sites have defined a broken and low accessible urban structure which has the potential to be well connected to different scales of the city and Hondo’s river drainage basin.

P.

124

1 2

3 4

1

3 125 P.

Main road & public transport vehicle

Big box retail parking lot

4

2

Polluted river & difference in height

Large non functional open space & informal path

Topography

0 Lower

Main roads

+20

+20 +40 Leveled

+60 Higher

Main road

Barriers

Contour line

The main road coming from the valley is diverged in three routes that follow the ridges and distribute transit to different urban areas/drainage basins, making this spot a node for the transport system.

Open space

Big box retail

Two large sites next to each other, one non functional open space the other a bib box retail, prevail as the largest area.

P.

126

Barriers

Built up area

Paths & streets

Informal Unpaved path street

Water system

Informal street

Urban facilities/ services

The combination of the two sites creates a large barrier in the urban fabric. In addition the condition of the streets along the river and the paths climbing the slope difficult the access to different services and urban facilities.

Sewage discharge

Run off

Sewer

Moreover the non functional open space is a natural area for runoff which is collected in a sewer and later discharged into the river.

However the last two situations show the potential of the site to connect in the local scale different urban and natural areas, flows and processes under the principles of the general strategy.

127 P.

BARRIER

NODE

P.

128

exploration

129 P.

Roads corridors

P. pocket Node

Open space as interface

Stop

BRT-line Built up Redevelopment Public area bike

The area of the big box retail will be redeveloped into a pedestrian pocket not by means of expropriation but by means of a public-private partnership with the retail companies. The area will be served by a BRT line running from the underground in the city to one CBD in the mountain which is currently accessible by insufficient roads and lacking of sufficient public transport.

Pedestrian Stair path

Landscape system

Bike/ Bridge pedestrian path

The local mobility will be improved by consolidating existing informal paths and streets, and adding new bridges to cross the river, new stairs to connect the lower with the higher area, new pedestrian and bike paths through the open spaces. This actions will improve connectivity and accessibility of existing urban facilities and the new pedestrian pocket.

Constructed Wetland

Rain garden

The open spaces will function as the landscape system with the creation of a continuous park along the gully through which the main run off flows. A series of rain gardens will collect run off and facilitate ground infiltration at the same time will provide for public recreational gardens, play grounds and sports facilities. Bio swales along the park will hold run off and treat the rainwater from urban run off before it goes into the river. A constructed wetland shares the original space of the channel with the clean river. The constructed wetland collects and treat sewage before being discharged into the river.

P. 130

131 P.

Current

P.

132

The polluted river, the unaccessible topography and the large monofunctional spaces create a barrier limiting flows and potential activities.

133 P.

Proposed

P.

134

The new conditions of the river, the improved accessibility and new activities transform the site into a permeable area with new flows across the entire site.

135 P.

NEW FLOWS & NEW CONDITIONS + PEOPLE’S INITIATIVE

P.

136

In this picture is shown a highly transited node and how people use this conditions together with their own initiative to transform ground floors from residential to commercial/services in order to improve their economical condition. With the passing time families improve and extend their buildings. This actions have brought many problems because the lack of attention from the responsible governmental authorities. Nevertheless, could it be possible to support and using it as a tool for developing part of a neighborhood? Could it be used to engage community to actually make their neighborhood?

137 P.

P.

138

Current

0

139 P.

1 year after intervention

10

25

50

The new flows from the node in the lower area to the pedestrian pocket, together with the new ecological sound conditions along the river and the open spaces create new flows that can be used by people in the area to start transforming their own environment by themselves. Supported by government, social and academic institutions, community are engaged to improve their socio economic conditions using their own initiative and the new activities brought by the flows and new uses.

5 years

0

10 years

10

25

50

P.

140

15 years

141 P.

NEW FLOWS & NEW CONDITIONS + STREETSCAPE

P.

142

143 P.

The low traffic conditions that offer the TOD pedestrian pocket are used to design streets not only with special areas for pedestrians but also to include a system of wetlands that treat the water from the new buildings to be reused. This creates new possibilities and the creation of a new urban environment where it used to be just a big parking lot and a monofunctional area.

P.

144

145 P.

The redeveloped area with mixed uses together with the new public transport node and improved pedestrian routs that connect the two sites will bring new flows to the area that can be used by the own people’s initiative to improve their living environment.

P.

146

The new landscape system connects the natural flows and processes with those of the city and people’s needs to retrofit each other in an attractive urban/natural environment.

147 P.

Sewage basin “Cristo”

7.4 Urban

P.

148

The detention basin “El Cristo� is considered a zone of environmental contingency because during rainy season all the sewage from the west of Mexico City is discharged in this place to be pumped out of the city. Environmental regeneration of the 111 ha detention basin is the first objective and would be a huge positive step in the environmental qualities of the city.

However after the regeneration it would be impossible to think of it as a natural reserve in the middle of the city. Instead an ecological urban park is proposed. The program of activities seeks to bring community into an ecological territory in which they can witness how if the natural resources and wastes are used wisely living conditions can improve.

CRISTO

Huixquilucan de Degollado Naucalpan South Huixquilucan

149 P.

Scale of the basin (red) in relation to other lakes in the city and the original lake.

4

2 1

3

1

3

2

stream inside the basin

The large open polluted open space is an urban void which is not only a source of pollution but a barrier that disconnects the urban fabric.

4

informal path along the basin

Basin is located next to important transportation infrastructures. However the P. 150 large polluted open space disconnects one from the other.

Barrier: local

Barrier: metropolitan

Built up

secondary road

The large open polluted open space is an urban void which is not only a source of pollution but a barrier that disconnects the urban fabric,

Disconnected roads and public transport system make more evident the role of barrier that the basin is currently playing not only in the local sale but also in the metropolitan connectivity.

151 P.

Barrier: potential flows

main road

underground terminal

commercial/ industrial services

education

underground terminal

Important commercial and educational areas are disconnected from mass transit systems, decreasing its potential no only in the local but in the metropolitan scale.

BARRIER

METROPOLITAN MUM

P.

152

Roads corridors: metropolitan mobility

secondary public t. / pedestrian road based street

Open space as interface: slow mobility + permeability

main road/ redevelopment built up stop rapid transit area

With the proposed TOD a new connection crossing the basin is made with a BRT which runs from and to the mountain and the main ring road improving the metropolitan connectivity.

In addition the roads that connect new pedestrian pockets are public transport and slow mobility based to improve local mobility across the site connecting fostered and expected new uses along the new corridor from the main ring road to the underground terminal.

153 P.

bike/ pedestrian path public bike/ bike parking

Open space as interface reclaim, recover & regenerate

underground terminal

Local mobility is supported with a new network of bicycle and pedestrian paths crossing the new reclaimed landscape of the basin and connected to the existing urban fabric and the new corridor along Hondo river. In this way not only is permeable but accessible for new uses in it.

The border of the basin is used as a metropolitan urban park with sports fields, community centers, urban agriculture farms, urban facilities and services. This urban park is provided of treated water for irrigation and non drinking water by the landscape system in the core of the basin.

Besides, the core is easily accessible and different social, cultural and recreational activities are promoted as part of a continuos demonstrative and educational program for community to understand the benefits we get from an ecologically sound environment.

Landscape system: collect, store, treat & reuse

constructed wetland

new lake/retention basin

The landscape system is made of retention basins, storage ponds and constructed wetlands. Constructed wetlands collect, separate and treat the sewage from the deep sewer before store it for irrigation and reuse of the new develope areas. The system of retention basins and storage ponds maintain the control of flooding risk of the basin at the same time the water stored is used for irrigation and reuse of the of the park and the new developed areas.

The new landscape system creates a micro climate around it and reintroduces biodiversity, biotic exchanges and new ecotones, transitional habitats for animals and vegetation creating a new landscape. Furthermore it creates diversity in the living environment and public spaces that serve a large area of the city to which is now accessible and connected.

The new park is located close to important roads and mass transit routes or terminals. This environmental regeneration could help to consolidate the area as an important urban center which redistributes the flows in the city, currently concentrated in the center and south.

P.

154

155 P.

current

possible: Lotus lake national wetland park - Tieling city China

possible: Park of luna - Heerhugowaard, Netherlands

P.

156

7.5

The system

157 P.

System

Origin - destination Drainage basin CONNECTING the pre-existing, facilities, society, flows, nature CREATING new conditions - BOOSTING new flows & activities.

P.

158

Subsystems Origin - destination River - lake

159 P.

Metropolitan connectors origin - destination Mountain - valley

P.

160

Replicate

161 P.

Polycentric

P.

162

Connected

163 P.

Origin: Polycentric Synergy of systems

Evolution: Disconnected territory of the mountain & the valley Fighting the natural system

Polycentric metropolis: A water subsystem articulated by urban functions, processes and needs

P.

164

8.

Conclusions

Mexico City is built on a dissected lake and the urban expansion has appropriated the mountains surrounding the valley. This has brought environmental issues mostly related with water such as extreme river pollution, drinking water shortage, excess of running water in the rivers during rainy season and excess of runoff have direct impact on the valley problems. Nevertheless it also has brought problems related with the whole living environment on the territory of the mountains such as a fragmented territory due to environmental and topographical conditions. So far problems of the city have been addressed either as valley or as mountain, not as a single system.

The thesis takes one river and its drainage basin as case study that can be replicated in the rest of rivers of the city. The focus of study addresses the ecological regeneration of the drainage basin as starting point for regenerating the living conditions and joint that articulates the territory of the mountain with the valley. The geomorphological characteristics of the drainage basin are taken as backbone to define a spatial strategy that can be replicated and shift the city towards a more balanced metropolis. In this way roads and rivers are proposed as corridors that different activities and human needs 165 organize P. according to the potential of the services

offered by the landscape.

The rivers together with the open spaces between the urbanization and natural areas forms the Multiple Use Modules that use the ecosystem services which is capable to provide to the city such as soil fertility and erosion control reducing torrential streams and flooding damages or waste water treatment as was shown in the rural and transition case studies. Moreover people can obtain side benefits from the new good conditions that carry an ecological sound stream like was showed in Naucalpan south case study. As for the metropolitan impact parting from the ecological regeneration the fourth case study shows the environmental and social benefit that can be reclaimed from a monofunctional piece of sewage infrastructure. This part of the strategy is related to the ecological regeneration of the drainage basin and the river and is addressed not only as a matter of protecting nature but through the act of regeneration engage community in this action by actually contributing in making some of the interventions and obtaining direct benefit from it.

The roads use the principles of a Transit Oriented Development to guide future growth as a complementary strategy to preserve and maintain natural areas important for

ecological functions, in advance of new development or to retrofit existing ones.

As shown in the case of using the pedestrian characteristics of the T.O.D. pedestrian pockets to make street scape interventions that can integrate the Landscape System into the urban setting and together create new conditions that support new activities in a new urban environment. Together this concepts and tools create a system carrying new good conditions in the living environment - ecologically sound and connected among existing and new systems - that retrofit each other. Rather than changing the way the city functions, by replicating this system to other areas in the city the scalar potential of the strategy can sew the structure of the metropolis.

This work represents an idea that just as monofunctional infrastructure, single target strategies*1 are not enough to deal with current urban problems. Furthermore it tries to open further debate on the way the metropolitan territory of Mexico City and many Latin American metropolitan areas are planned limiting the task of urban discipline within administrative borders and not in the realm of territory systems such as the basin of Mexico’s Valley *2.

*1 Single targe strategies only focus on ecological or social regeneration, only public space or only connecting areas or only accommodating growth and so on‌ *2 Mexico city is divided both in administrative and geo morphological entities. Geo morphological divitions are made by separating the valley from the mountains, mainly because the repercussion of problems on the mountain are down on the valley.

Bibliography Anthony Walmsley (2005). Greenways: multiplying and diversifying in the 21st century. Landscape and Urban Planning 76 (2006) 252–290 Blanca Jiménez C., Marisa Mazari H., Ramón Domínguez M. y Enrique Cifuentes G. 2004. EL AGUA EN EL VALLE DE MÉXICO, EL AGUA EN MÉXICO VISTA DESDE LA ACADEMIA. ACADEMIA MEXICANA DE CIENCIAS. Bernick, M. and Cervero, R. Transit Villages of the 21st Century, McGraw-Hill, New York, 1997.

Escamilla Herrera Irma, Santos Cerquera Clemencia. 2012. La zona metropolitana del valle de méxico: transformación urbanorural en la región centro de méxico. Instituto de Geografía -Universidad Nacional Autónoma de México.

Gonzalez de León, Teodoro;, Kalach, Alberto. México Ciudad Futura 2020, Logística 101, México.

Hung, Ying-Yu; Aquino, Gerdo. Landscape Infrastructure: Case studies by SWA. Birkhäuser Basel. Basel, Switzerland. 2011.

Larry D. Harris; Reed F. Noss. Nodes, Networks, and at All Scales MUMs Preserving Diversity. Environmental Management 1986, Volume 10, Issue 3, pp 299-309 Legorreta, Jorge. 2009. Ríos, lagos y manantiales del Valle de México. Universidad Autónoma Metropolitana.

Millennium Ecosystem Assessment (MA) 2005. Ecosystem and Human Well-Being: Synthesis. Island Press, Washington.

National Research Council. Mexico City’s Water Supply: Improving the Outlook for Sustainability. 1995. Washington, DC: The National Academies Press.

Partha Dasgupta, Simon Levin, Jane Lubchenco. Economic Pathways to Ecological Sustainability:Challenges for the New Millennium.

BioScience, 2000, 50(4), pp.339-345.

Priscilla Connolly. 2005. Tipos de poblamiento en la Ciudad de México. Universidad Autonoma Metropolitana - Azcapotzalco. México.

Sybrand Pieter Tjallingii. 1996. Ecological conditions: strategies and structures in environmental planning. Doctoral Thesis TU Delft.

Torres-Lima, Pablo, Beatriz Canabal-Cristiani, and Gilberto Burela-Rueda. 1994. Urban Sustainable Agriculture: The Paradox of the Chinampa System in Mexico City. AGRICULTURE AND HUMAN VALUES - Winter 1994, pp. 37-46 Webster’s Unabridged Dictionary 3rd ed., New York: Random house, 2009.

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