One could say, that the city of Santa Cruz de la Sierra in Bolivia is an extreme example of rich and complex mixture of urban patterns, sometimes broken by landmarks and urban elements. The historical grid is overtaken by the radial system of the modern city’s masterplan, which gets weakened and cut by the presence of nature – Pirai river, as well as inputs of civilization – local airport. All this happens due to the fast growth of the city, which forced the government to search for new possibilities of restructuring the city’s infrastructure. However, due to the extents of the rapid expansion and lack of funds, the control of the urban growth is not efficient and chaotic, unplanned elements appear, especially at the perimetric areas.
All the spatial and formal composition of Santa Cruz as well as its social correlations made it an interesting model of urban development to study.
Santa Cruz de la Sierra, is the largest and most populated city of Bolivia and the economical and industrial leader of the country.
In the last 50 years, the population of Santa Cruz has grown extremely rapidly, not allowing the infrastructure to keep up with the pase of the demands of population growth, leading to problems with the traffic system, the low number of green zones and other complications related to the uncontrolled city expansion.
To comply with the growth, the city of Santa Cruz convoked and international competition for the master plan in 1958. The winning team was an urban planning company from argentina called Techin. The company worked with Phillip Lohbauer, a german architect living in Sao Pablo. Expressed shortly, the idea he proposed was organizing the city with a series of concentric rings and radial streets which develop away from the center.
However, to discuss the urban complexity of the city, we have to start with the historical grid, broadly developed in South America by the spanish conquerors in the XVI century. The grid consists mainly of square elements called manzanas. They are arranged between streets and avenues crossing each other under right angle and their pattern is very strong and homogeneous in the historic center. The square manzana weakens as we move away from the centre to later get transformed into a rectangle or polygon which manages to establish itself before the first ring of the new urban plan starts.
Today however, the city is mainly composed by rings, introduced via masterplan in 1958. These series of rings take as their geometrical center the oldest part of the city, enclosing it within the first ring. The rings increase in their radius to shape the rest of the city and its peripheries.
This strong radial pattern, highly influences the urban development of Santa Cruz. However, due to its poor and slow execution, not keeping up with the fast population growth, the further from the centre, the more chaotic the city tends to become and the rings lose their gathering force.
We can clearly see, the concept of border of a zone is clear in the inner rings. The most clear and defined urban elements lie within the first ring in which demographical density is high as well as the network of streets is well structured and maintained. Between the first and the third ring, blocks and streets are aligned in a fairly concentric way. In the outer part, the grid and border system become less and less evident as a result of of the not fully established urban plan and fast inflow of people. The streets and blocks start to become more chaotic.
After the fourth ring, the periphery of the city starts. Heavy immigration has caused an incredible explosion in the urban footprint over the last fifty years. Those perimetric zones are mainly inhabited by the people migrating from the countryside looking for a better life in the city. Due to their lack of qualifications and lack of economic resources, their financial situations and poor living conditions, leads towards greater number of crimes, in the peripheral areas of Santa Cruz. These zones due to their position also lack access to educational facilities and health institutions.
Breaking the continuity
No matter how clear the urban pattern is and to what extend the city can introduce and execute it in favor of the entire population, there are always moments where the infrastructure network gets broken or limited.
Looking at a city plan, one can notice that the rings are complete until the fourth ring and then the clear pattern gets broken. This is due to Piraí river passing through the north-west of the city which greatly weakens the urban-stamp imposed by the city with its series of rings. The river works as a limit for the further expansion towards West, as the economical, logistical and planning problems are too elevated to go ahead and develop the city on the other side of the river.
The other landmark that has broken the radial system of Santa Cruz is the airport, El Trompillo. As the airport has been founded before the rapid expansion of the city, with time, it has been engulfed by the urban context. The stretch of the landing line has caused a cut in the continuity of the third and fourth ring. This initiated the construction of Santa Cruz’s new international airpot called Viru Viru which is located at the northern part of the city, and the old, El Trompillo airport nowadays serves only domestic flights.
Green pause in the density
Of course, the density of the city is also broken by few green zones. But those parks, unoccupied urban voids, are forms that comply with the city system rather than destroy its continuity. The green area of the main square constitutes a pause to the densely urbanized context that surrounds it. It is very interesting to notice how this green space can make such an important hierarchy within the rich city pattern.
Another pause in the urbanized context is the city’s biggest, centrally located park, El Parque Urbano, which Mario Botta describes it as a vital green space within the historic city, a rectangular urban void surrounded by a series of concentric commuter roads leading out to the outlying neighborhoods.¹
Looking at the plan, we notice the strong form of the parks, green zones, and unoccupied voids within the city. But their small number is insufficient to the demands of the population and therefore they become more and more problematic.
Decreasing presence of the city
Even though the current composition of Santa Cruz arouses many problems, it is amazing to experience this complexity and constant change in urban density. All this mixture of urban patterns and how they enrich/fill in with each other, can be well observed simply by moving away from the city centre towards the peripheries. At the beginning everything is very dense and the strong presence of the city center is felt. Later, as we start to move away through the radial streets, avenues, use the rings to change our direction, we start to feel that the city becomes more loose, every zone less defined, borders more chaotic. Finally, when we leave the loose city borders behind, we understand that the domination of the city is weakened by the presence of open land, to be later totally lost when we arrive at villages of linear, non-centrical shape. They are linear because their center becomes the road. That sequence of zones, change of the density and appearance of different urban elements, from one side amazes with its diversity and richness of form, however, on the other side makes us aware of the problems rising from such a complex composition.
The city can still be reorganized, but we have to notice the importance of the influence given by the existing radial system and the limit that the river imposes on it. More, the main challenge to be solved is to start developing an urban plan that works with the rapid urban growth. But the new concepts should be planned according to the current economical situation, that doesn’t permit expensive infrastructure to be built. With the current pase of population growth, the creation of new rings seems to be unavoidable and happens in such a rapid way, that the infrastructure connecting it with the centre of the city becomes insufficient. The solution in this case, could be developing city vertically, building high-rise buildings and so densifying the city fabric. However, the costs of such a constructions are much higher than expansion in a horizontal plane. Therefore, urban problems need to be resolved taking costs as the main consideration.
¹ Mario Botta Architetto official webage, Monument for the Cumbre De Las Americas in Santa Cruz De La Sierra, Bolivia, http://www.botta.ch/Page/Pu%201996_316_SantaCruz_en.php, 14.01.2011, 16.00
Fig. 1,2,3,4,5. Banco de planos, Oficialía Mayor de Planificación, Gobierno Municipal Autónomo de Santa Cruz de la sierra