A strategic intervention for the recovery of Jaboque wetland in Bogotá - Colombia WETLANDS ON THE EDGE A strategic intervention for the recovery of Jaboque wetland in Bogotá - Colombia POLITECNICO DI MILANO SCUOLA DI ARCHITETTURA E SOCIETÀ Master of science in Urban Planning and Policy Design Academic year 2011 - 2012 JUANA MARCELA LEAL SIMBAQUEBA Matricola: 766713 THESIS SUPERVISOR: EUGENIO MORELLO “If you want to build a ship, do not call people togheter to provide the pieces of wood, to command and to do the work, but call them on the desire to the spacious and endless sea” Antoine de Saint-Euxpéry Abstract The global awareness of urban wetlands as areas where crucial issues as urban growth and policies against climate change overlap, must be addressed with critical urgency on developing countries with rapid rates of transformation. The late consciousness about the environmental value of Bogota wetlands have created a rich field of discussion regarding the role of these places in the city, but specially and what constitutes the main purpose of this investigation, the deve- lopment of a vision which could lead to new kinds of physical interventions bet- ween the protected areas and the existing urban settlements. This work aims at recognizing and providing basic principles to guarantee that these physical reali- ties are compatible with the needs of the main natural elements which constitute these ecosystems; for instance, the urban wetlands are intended as places which cannot be separated from human action and presence, and the other way around, human settlements are influenced by the physical proximity of wetlands. Refe- rring to urban ecology principles, wetlands and human settlements are intended as part of the same ecosystem and their reciprocal relations from an urban design perspective is the object of this investigation. There is a visible polarization among environmental actors which have been wor- king for the recognition of wetlands as protected areas,and public institutions in charge of the management and regulation of these areas as public space.Both perspectives influence and determine the way in which the inclusion of these areas in the city is planned,most of the time with solutions that could be seen as banal as the design or location of a bike path or a simple fence. Furthermore,this situation puts in evidence stereotypical ideas which influence the sort of interven- tions and are responsible for the physical layout of the place. The urgency of this kind of reflections could be illustrated on the urban transfor- mation of the wetlands.In fact, we can recognize a relation among the dramatic consumption and devastation of soil during the second half of the 20th century and the profile of the settlements which invaded these areas.Degradation and po- verty determined the image of the western border of the city for a long time. Now, that the city has started to intervene and recover these areas and the image of the border has gradually been changing, new urban patterns along the wetlands are emerging. For instance, the appearance of gated communities and twenty storey buildings urge to ask if these could be interpreted as some sort of succession pro- cesses and how these dynamics affect the perception of the wetlands as public space. .A trivialization of the wetlands would mean the loss of an enormous opportunity to create a new border for the city based on new paradigms able to recover values from the existing situation. So far, wetlands have been interpreted in a very simple way; either to get rid of waste, the cause of flooding and disease, and in the best of the cases as potential golf fields or parks, always imposing over them physical transformations according to human needs, forgetting that they already have a vi- tal mission in balancing the ecosystem (drainage, biodiversity and environmental quality in general). The Jaboque wetland, for its size and location, offers interesting conditions to ca- rry on the morphological investigation in order to define series of principles which explore this new physical dimension, and in particular, the construction of con- cept-plan and master-plan guidelines, aiming at overcoming typical limitations of general and not site-related policies, and finally which could influence actions on other wetlands with similar characteristics. Aknowledgements I would like to take this opportunity to thank the following people for their contribution to the successful completion of this thesis: • Politecnico di Milano and Colfuturo, for their support with the continuation of my studies to become an urban planner and a better architect. • My parents, Consuelo and Javier, for always been here, for their love, inconditio- nal support and trust during this two years. • My supervisor, Eugenio Morello, for his time and continuity which were funda- mental to achieve the objectives of this thesis in the proposed schedule, for his curiosity with the subject, the respect and trust. • Natalia and Felipe, thanks for the interoceanic bibliographic support! • The Humedales Bogotá team, first of all thanks for your commitment and love for Bogotá and its wetlands, but also for letting me be part of your group. • Claudia Manconi, for being such a good friend since I put a foot in this country, for her generosity, for Chiara and Davide and our Sardegna road trip, for taking a break of your super fancy londonese life and been here to support me once again, • Juli, for this two years of hard work, all the coffee, tarallini,and library that we have shared. Thanks for been always available and your infectious love for this profession. • Cata, specially thanks for been here today and for your understanding and pa- tience during this last week, it meant a lot to me. • Juanito, thanks for your unconditional help, these two years would not be as half as fun without our controversial discussions and the continuous dose of drama . • Isabel, for your sincere interest, bright remarks and interesting conversation. • Thanks to all my classmates, from whom I have learnt so much, not just about urban planning, but about the delightful places around the world where all come from. • Thanks to Mariachiara and Mariangela for being such a beautiful human beings and sharing with me this last year. • Thanks to my friends back home, that are waiting for me with arms wide open and for whom the distance has not ever been an obstacle. • For all the people who have sincerely been interested in the subject of my thesis and that have shared their opinions, knowledge and advice. Contents Introduction _ 1 GREEN INFRASTRUCTURE AND URBAN FORM_5 Wetlands _ 7 Urban wetlands. Atributes, problems and values _ 10 Landscape ecology and green infrastructure _ 17 Sustainable urban form _ 22 Resilience _27 THINK GLOBAL ACT LOCAL_ 31 Bogotá’s growth and its urban form _ 33 From ecological structure to green infrastructure? _ 41 Flooding and other environmental issues _ 44 Bogotá’s wetlands _ 48 Engativa and the Jaboque wetland _ 67 INTERVENTIONS ON THE EDGE_85 Expanding the wetland _ 87 Concept plan_ 91 Master plan _ 95 Catalogue of actions_99 Ambits of intervention _108 FINAL CONSIDERATIONS_125 Bibliography_ 129 List of pictures _137 List of figures _139 List of maps _141 Introduction The geological past of Bogotá reveals that during the Quaternary period, most of its current surface was covered by a gigantic lake (Tunha/Humboldt), which gradually changed its contained condition when a series of climatic chan- ges during the Pleistocene, and some other morphological transformations like the deepening of the “Salto del Tequendama” cascade, ended up with the drai- nage of a vast quantity of water. (Calvachi, Guarnizo V2, 31) This transformation is recalled on the oral tradition of the prehispanic Muisca population who settled down in the area. The myth tells that people was suffering because downpours and flooding were ruining their crops, all of them sent as a punishment from god Chiminigagua, later, thanks to the intervention of god Bochica, who using his ma- gic powers, let the water flow through the Tequendama cascade(EEAB, CI Colom- bia, 2000 V1, 157) From ancient times, recognition of water and wetlands on the Altiplano Cundiboyacense determined the relation of people with its environment, from their conception of the universe to the solution for basic needs for surviving, there are still traces which let us see the impressive agricultural system that they used to cultivate; “an infinity of canals and elevated fields with patterns of reticular distri- bution doing zigzags in parallel or fish spine shaped patterns, along both sides of the river” (EEAB, CI Colombia, 2000 V1, 159). Beyond that, it shows the high level of anthropization of wetlands since early stages. The Spanish colonization without any doubt marked a big transformation in the landscape. The foundational center of the city was located on the foot of the eastern Bogotá hills, near the water springs and far from the wetlands, only a few indigenous settlements would remain near them. This first situation would create the first rupture between the city and the wetlands, the lack of a sewage system implied that waste would be throw down the river and disappear in the wetlands, however, at this point damage for the ecosystem was very low, and it was able to recover because the waste was not over passing its charge capacity. Although the original extension of wetlands before the Conquest has not been calculated, it has been estimated that the remnant surface is situated under a 5% of what it used to be. By the middle of the past century the coverage area could have reached around 50.000 Hectares in the Bogotá’s Savanna, recently it has been estimated that the surface coverage has been reduced to 500 Hectares.