CORNELLÀ DE LLOBREGAT NEW ECO CENTRALITY
METROPOLITAN E-STUDIO CARLES CROSAS AND JORGE PEREA MARCOS GÓMARA MIGUEL HERNÁNDEZ AURÈLIEN VILLEROY DE GALHAU
INTRO The city of Cornellà is one of the first settlements established in Llobregat rivers’ delta plain. An original roman foundation dedicated to the farming exploitaiton, it follows a similar development as the rest of the towns of the Vall Baixa –Llobgregats’ Low Valley-. Singularized by its proximity to Barcelona –being part of the city administratively until 1717-, and to the commercial port of the city –the Zona Franca-. The Vall Baixa turns in the XXth century into a major productive place in the country. That happens through the construction of the artificial irrigation channel so called “de la Infanta”, which allowed intensive exploitation of the agricultural park. And with the arrival of the Industrial Revolution to the peninsula, here implemented by the presence of a commercial port. The needs of communication and transport of the city of Barcelona, demanded the construction of an enormous road infrastructure system. Which perched insensitively on the territory, constricting the riverbed and creating numerous physical barriers all-over the whole valley. In Cornellàs’ case, vast mineral industrial tissues substituted the croplands that initially surrounded the town. This industry is today in clear decline. The great slope on which the A-2 motorway rests, nowadays disables the relation of Cornellà with the riverbed and the agrarian park.
2. Sustainable transport thought to relief the central city The decongestion of the city, is a priority on the welfare of a durable metropolis. Both to reduce pollution and to encourage the establishment of rich relationships between citizens and activities, creating recreational spaces is not the only need. We need to rethink the transportation systems in the city. Reducing private motorized traffic and thus recovering the approach of the city as an area of phenomena occurrence. Respect other European cities, Barcelonas’ street grid system facilitates car drive around the urban fabric. The traffic and speed, pollutants, also generate conflicts with the activities on numerous occasions in the city. Against this, administrative action trying to regulate this imbalance is necessary. If many European capitals have already placed reducing traffic in their downtowns as a main point of their agendas, Barcelona must and is taking this as a priority of the urban improvement. This has to be done through the promotion of common transport, environmentally cleaner, sustainable and richer for urbanity. Cornellà is located at the confluence of two highways that access several major traffic arteries of the city. To raise a reduction in private motorized traffic access to the city, Cornellà is key to think of a traffic exchange point to regulate this situation.
PROBLÉMATIQUE AND STRATEGIES
3. River flood regime
After this short introduction, we present today’s main issues of Cornellà that with an ecological urbanism thought will lead us to present some strategies. This will afterwards allow us to present the future scenarios to define an eco-urban project for Cornellà.
Both by unconsciousness and mainly by poor planning in the development of the building in the Vall Baixa de Llobregat, the transformation of the territory has led to negligence in the flooding management of the Llobregat River. The unstable course of the river, whose phenomenology will probably be increased with stronger rainfall patterns caused by climate change, is something that directly affects Cornellà. In order to increase the area of buildable land, two large earth slopes -the “motas”- were built on both sides of the river. They aimed to control the water volume of large floods, but also reduced even more the area of the river ecosystem. It is a “channelling” of questionable effectiveness in the event of a big flood that could invade the urban fabric of Cornellà.
1. The river park, recreational space to decongest the metropolis If something gives a unique character to the Vall Baixa, it is the undeniable presence of the river course, which is indeed its orographic origin. The flood regime, the productive fertile lands and the mountains of the valley, do not allow a dense and continuous urban growth. These non-built spaces, generators of the metropolitan city, are themselves the character of opportunity in the territory. The metropolitan city, require these large spaces as recreational decongestion areas for the metropolis. As we have seen, the construction of major infrastructure communication roads and the semi-canalization of the riverbed, are the two main physical barriers between Cornella and the river park project. Cornella is the first population of the Vall presented to Barcelona as an access node to this park. To rethink the relationship of the site with the river is undoubtedly our first approach for a project.
These ramps, on which some large infrastructures were later posed, are major barriers to the relationship between the towns of the Valley and the river park. Changing these titrations in the strategic enclave of Cornellà, lead us to propose a surveying system to manage -better than today if possible- floods. While these modification would still allow accessibility to the River Park and the renaturation of the riverbed biological system. 4. The ecosystem of the River Park
As we have seen, it is unthinkable to completely recover Llobregats’ modified ecosystem after the transformation of the delta plain in an agrarian park to feed the city of Barcelona. It is important however to propose, as far as possible, a rethinking of the River Park. Battered persistently in the early twentieth century with the removal of meanders and the construction of the “motas”. The space should not only be a space of recreation for the metropolis, but must be a major biodiversity axis. From which we could extend infiltrations in the mineral built city, and to other ecosystems, the big mountains ones or to other embedded in the urban fabric. This should remain compatible with the required recreational use of the park for the citizens of the metropolis. 5. Urban transformation of Cornellà As has been explained, during the twentieth century, the fields surrounding Cornellàs’ core were replaced by industrial estates whose activity was linked to the proximity of the port. These are monofunctional and mineral packages today in decline. Some parts of these have been transformed by the creation of facilities of local and metropolitan scale on the area near the river park – a big mall, Cornellàs’ fair for public events, a public swimming pool or hotels for the airport ... -. The park remains though hidden behind the slope of the highway. If we consider that Cornellà is, because of its unique accessibility, suitable for further transformation of riverfront; we believe this may be the starting point for an improvement urban plan that infiltrates to the rest of the settlement. With new uses and morphological change, leading to greening and urban land demineralization. 6. The production of the agricultural park Baix Llobregat has been historically and especially since the Industrial Revolution, the major producer of food for Barcelona and its metropolis. Globalization and the explosion of goods transportation in recent decades, has relativized the importance of local production as essential in the genesis of cities and civilization. But this phenomenon entails an energy cost and environmental degradation. Given the current media coverage and awareness of this, we should expect a "return" towards sustainability production methods. Added to all the problems above, we think of Cornellà as the advertising scene of an agricultural park whose local and sustainable production is essential in the circular energy and material consumption system of the metropolis. This can give clues of the activities that could be implemented while transforming Cornellà . It can also support us defending the need to establish relationships with the agricultural park on the other side of the river. 7. Sustainable energy systems
To think othe city development based on sustainable energy systems, except in specific cases and beyond the approach circular energy expenditure, is still something abstract. Since it depends largely on the progress to occur on technological advances . However, we can intuit some hypotheses for rules and practices affecting the transformation project proposed for Cornellà. Thus, urban transformation projects should integrate the production of solar energy on rooftops to try to achieve energy self-sufficiency. Or, for example, the slowdown and stagnation of water in the riverbed could be preceded by a water jump to produce electricity. Even more, the metropolitan equipment associated with the visibility and revitalization of the agricultural park, could be associated with research on production of biogas or biodiesel from agricultural waste of the park. 2040 SCENARIOS AND PROJECT INPUTS METROPOLITAN NEW ECO-CENTRALITY Transformation of Cornellàs’ riverfront The fundamental act is to transform the supports of the A-2 road infrastructure. We propose to substitute the huge earth slopes with a viaduct. Under which, urbanity, recreation, ecology and activities could interact. Turning from barrier to an exchange membrane of relationships and uses. Creation a traffic exchanger and a sustainable parking system The transformation of the structural system of the highway would also be justified by the creation of the traffic exchanger. Reducing incoming traffic in the city of Barcelona, it would be necessary to create a public transport system that would link with tram and train Cornellà, and the new station line 9 Prat de Llobregat -across the River-. It would be connected to Barcelonas’ downtown and the airport. And would reduce traffic, making easy circulation of commercial transportation to and from the Logistic Port. The creation of the exchanger, a landing of visitors to Cornellà, brings us to think of the need to integrate large surface parking areas in the project. Regulatory system of river flooding By removing the current flood control barrier -the A-2 slope- it is necessary to propose a system of management of them. A more efficient system for a bigger volume of flood water. We propose this to be done by a staggering of the new river "beach" Cornella. Thus, a series of platforms-rafts for flood control would appear. The floods would temporarily affect the volume of these, the lower, for normal small ones. And in case of a big
flood, the uppermost would be reached. These spaces that we propose would be occupied by the parking lots. Scenically they should be integrated into the landscape of the proposed recreational space of Cornellàs’ riverbeach. Making part of the park itself. Cornellas’ Agropole Exploiting synergies between Cornellas’ dynamic downtown, the renovation of the riverfront, the creation of a new metropolitan centrality at this point and the transformation of the industrial sector in decline, we propose a series of programs related to the implementation of the agricultural park. Research programs in organic farming, investigation on energy systems through fermentation and treatment of agricultural or/and urban waste and; but also social and cultural awareness metropolitan equipment’s in accordance with Cornellas’ unique opportunity. Renewable energy production Without being the structuring axis of the project. We propose the creation of a waterfall before the stagnation space, to produce clean electricity. Also we propose the requirement to achieve a certain energetic autonomy in every inspection to occur in the industrial tissue in transformation, given the revaluation soil done through the metropolitan transformation
I INVESTIGATION ON THE SITE AND THE SUBJECT
HISTORICAL EVOLUTION
CURRENT-STATE VIEW
FIRST IDEAS
RIVER FLOODS PLAN
COMMUNICATIONS PLAN
BIOLOGICAL SYSTEM PLAN
MINERAL SOIL PLAN
ENERGY PLAN
IMPACT OF PROBABLE NATURAL PHENOMENA IN THE UNCONTROLLED DEVELOPMENT OF NOWADAYS METROPOLIS
DEVELOPEMENT OF BIODIVERSITY IN NATURAL SPACES -STAGNATED WATER-
PHYTOREMEDIATION SYSTEM FOR WATER TREATMENT
II MIDTERM REVIEW
III FINAL REVIEW INTRO
PLANO MASA DEL PROYECTO
PROJECT STRATEGIES
FLOOD MANAGEMENT
PHYTOREMEDIATION
Through modification of the topography of the Llobregat riverbed in CornellĂ , not only permeability of the urbanity of the city on this stretch to the other side is generated.
By doubling the river course, and reducing the acclivity of the river here -that concentrates at the new watermill-, the water speed slows down in this 3 km stretch.
Also an augmentation of the volume of space provided in this space for river flooding is created.
Stagnation difficults sludge removal, which will favor the biological enrichment of the river.
MAXIMUM WATER VOLUME OF THE CURRENT SECTION
Through a system of specific plantations on the edge of the river, it is intended to reduce the level of hydrocarbons, salts and other contaminants that make the Llobregat one
(127x15) m2 x 3.000 m = 5,715,000 m3 MAXIMUM WATER VOLUME WITH THE PROPOSED SECTION (407x15) m2 x 3.000 m = 18,315,000 m3
PROJECT STRATEGIES
NON-ACCESSIBLE AREAS TO STIMULATE PROTECTED ECOSYSTEMS
PARKING ASSOCIATED TO THE TRAFFIC EXCHANGER INTEGRATED IN THE LANDSCAPE PROJECT
When remodeling the topography of the river bed to increase the volume for floods and to propose the phytoremediation treatment, a succession of enclosed spaces are created in the middle of the river.
The platforms located between the Cornellà urban front and the river bed, are profited to create a parking integrated in the landscape of the river park, with a capacity of 4,000 vehicles.
40 Ha. of space in Cornellà, reserved for wildlife occupation that reinforces Llobregats’ potential as an ecological corridor.
It is a space that would hardly be used in another way. Since it is under flood danger, and under the new “viaduct” of the highway -therefore it doesn’t have photovoltaic potential.. The pavement should be thought for water recovery where possible, public transport system that connects it to the existing network is proposed by us.
PROJECT STRATEGIES
LLOBREGATS DELTA ENERGY IN DATA We make an estimation on the worked spaces in order to produce clean energy To gives us an idea of the untapped production capacity of the LLobregat in this specific place HYDRAULIC ENERGY 653 MW / year minimum PHOTOVOLTAICS ON PROPOSAL 138,834 MW / year minimum. PHOTOVOLTAICS ON EXISTING INDUSTRIES 384,982 MW / year minimum
PROJECT STRATEGIES
PERMEABILIZATION OF THE INTERVENTED SOIL FLOOR 1 - vegetized land, natural infiltration of water into the land, no water for later use is recovered.
FLOOR 2 - Parking, gravel and water collecting shunts on the parking lots + vegetable parterres Potential volume of water collected for use Area = 116.624m2 Permeability = 60% (116.624x330,7) = 23.140.534l / year
FLOOR 3 - Public space by the river, atlantis pavement for watercollection + vegetal parterres Potential volume of water collected for use Area = 248,411 m2 Permeability = 40% (248.411x330,7) = 32.859.807l / year
POSIBLE CRONOLOGÍA DEL PROYECTO
2020
2030
2040
2050
Remodelación del cauce fluvial, construcción de la presa para la producción de energía hidroeléctrica - gasto
Permeabilización de tramos de la ronda - gasto
Construcción de edificios de servicios privados (centros de investigación, comercio- y viviendas privadas -ganancias para compensar el gasto
Construcción del anillo-intercambiador - gastos
Construcción del sistema de taludes bajo la misma para crear el espacio de crecidas, que será aprovechado por el parque -gasto Construcción de la línea de tranvía Cornellà - Frente Fluvial- El Prat - gasto Comienza la rentabilidad de energía de la presa -(pequeñas) ganancias
Comienza el funcionamiento del párking - ganancias Construcción de vivienda pública y equipamientos - gasto Construcción de otros edificios privados - ganancias
PERSPECTIVA
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