LOCATION: Delta Paraná River, Rosario, Argentina.
Arch. Walter Gustavo Salcedo
YEAR 2015 / 2017
The paper addresses the system of islands that conforms the Parana River Delta and its relationship to the coast of Rosario. The main goal is to develop a strategic plan based on guidelines that ensure sustainable growth, considering the great environmental value of this wetland and its high vulnerability.
The impact of the Rosario-Victoria Bridge, the solid increase of vessels, the policies implemented by the government of the city in the last thirty years that encourage more people to enjoy the river, the predation of the environment, and the absence of a plan to coordinate and strengthen the projects on both sides of the river are, among others, the most salient aspects of this situation.
The following problem areas are recognized:
1- Disorder | Incoordination.
Merely to understand a river 55km. wide in the sector between Rosario, belonging to the province of Santa Fe, and Victoria, belonging to the province of Entre Rios is really very complex. The legal/legislative framing is quite blurry sometimes. If we understand that the legislation of the vast majority of the islands -except the recent formations- corresponds to the city of Victoria, including those in front of Rosario city. However, Victoria does not have the resources to control the exploitation that is given to the territory from Rosario. Political coordination between the administrations of both provinces (Santa Fe / Entre Rios) and two cities (Rosario / Victoria) should be a key milestone to establish clear rules of operation.
2- Predation of resources.
The continuous growth of the nautic park of the city of Rosario has generated a greater number of marines throughout the river bank, which determines a greater transfer of passengers to the island system, reaching between 30,000 to 40,000 people per weekend during peak season, combining small private boats with larger public transportation, concentrated on the two boarding platforms owned by the city: Fluvial Station in central area and Costa Alta in the northern sector. This exponential growth multiplied the number of hostels and clubs on the islands, as well as private housing for weekends. In parallel, in recent years it has also increased agricultural / livestock farm, fueled by the commercial boom of soybeans, which encourages the burning of grasslands, often determining wildfires. These new constructions and uses of soil differ markedly with the original use that was given to the territory, almost untouched, with only a few fishing ranches.
3- Lack of infrastructure | Disconnection.
The islands are not equipped with the necessary infrastructure for the number of people who are visiting them. This lack of infrastructure contrasts sharply with the super-structure that represents the Rosario-Victoria Bridge, which generates not only a strong visual and sound impact, but also allows a vehicular point of arrival to the islands, something unthinkable before. Also, the lack of a network of public nautical-transportation is another point to note. This condition does not accompany the incremental occupation of the islands, accentuating the problem.
An area of 93.24 km2 and 28 km in length is defined for this research. Compared to the area of the city of Rosario, 178.79 km2, the intervention area accounting for 52.15%.
This area will act as proof of concept of this investigation, in order that it can be extrapolated to other sectors of the wetland. Then, the different stages of development are as follows:
1-Collection and planimetric-bibliographic material available, as a starting point to produce the first drawings of own authorship in which it is possible to coordinate information available.
2-Four field trips were necessary to complete a planimetric survey of land uses (existing settlements, resorts, inns, camping areas, productive sectors) as well as morphological changes intrinsically linked to variations of river-level.
3-Mapping situations determined by the variation of the river-level; including null areas and areas with potential to be used.
4-Detection of problems and / or 'sectors of opportunity'.
5-Analysis of Case Studies and definition of intervention scenarios.
6-Proposal of overall organization, zoning and internal-external communication. Circuit-Uses.
7-Development of sectored proposals through academic exchange with different chairs.
As a primary objective, the research aims to contribute in the preservation of the existing ecosystem, of immeasurable value. While there are positions carried out by non-governmental organizations promoting zero intervention in the wetlands, this work is framed within a philosophy that considers the current lack of an organizational plan as one of the main causes that lead to uncontrolled predation of natural resources.
1-Develop a planimetric survey and mapping of activities that consider the river dynamics.
2-Formulate proposals for management and planning of future interventions, defining protocols of design and infrastructure.
3-At legislative level it is imperative to propose management tools and legal frameworks between the two provinces.
The research attempts to set the basis to intervene around the delta of the Parana River, not only in the Rosario sector. Methodological mechanisms could be applied in other sectors of the ecosystem, and even in other wetlands in the country.
2_STUDY OF CURRENT STATE
2.1 CUENCA DEL PLATA - PARANA RIVER DELTA
La Plata Basin, with an area of 3,200,000 square kilometers is the world's second largest watershed. It covers important territories belonging to Argentina, Bolivia, Brazil, Uruguay and Paraguay. Precipitation falling in its field meet in two water courses, the Parana and Uruguay rivers, which then flow into the Rio de la Plata which eventually flows into the South Atlantic Ocean. The average flow of the basin is 23 000 m³. There are numerous hydroelectric dams in operation, mainly in the Parana River basin. This does not prevent most of these courses be navigable by ships of medium-sized and almost all of them by barges. La Plata Basin forms the main water reload system of Guarani Aquifer, one of the largest inland freshwater reserves in the world. The basin serves as a seat for a population of over 100 million people, so uncontrolled human interaction could produce significant changes to both the basin and the quality of life of its inhabitants.
Parana River Delta with 20,000 km2 and a length of 350 km, has its origins close to the city of Diamante, Province of Entre Rios, where Predelta concludes. It is divided into three main regions: the Upper Delta (from Diamante to Villa Constitution, Province of Santa Fe), the Middle Delta (from Villa Constitution to Puerto Ibicuy, Province of Entre Rios) and Delta Inferior or training (from Puerto ibicuy to the mouth of the great estuary of the River Plate).
The Parana Delta is part of Mesopotamia and it is considered one of the largest deltas in the world. With regard to its biome, despite its southern location, the presence of large bodies of water and low altitude produces a microclimate that favors the proliferation of animal and plant species, resembling tropical latitudes. The islands of the Parana Delta owe their existence to the large amount of sediment carried by water from the Parana. His bed is occupied by banks of sand and clay that force their permanent dredging to allow navigation.
2.2 DIVISION OF TERRITORY - LEGISLATION
The division of the territory reflects the contrast generated by the geographical proximity of the islands to Rosario, and its legislative distance, governed by the City of Victoria in Entre Rios. The lands donated by the Foundation Deliot to the Municipality of Rosario, have been usurped for agricultural-livestock farm, deriving this even in the construction of embankments for the diversion of natural watercourses land. In turn, there are not regulations that define specific areas of land use, which generates, as reflected in section 2.4, an overlap between residential, recreational and productive uses.
2.3 HISTORICAL RECORD OF RIVER LEVEL VARIATION
The chart of variation of the level of the river in the city of Rosario allows multiple readings. On the one hand, understand the concept of dynamism imposed by the river, constantly fluctuating with an amplitude of oscillation of 5.7m. In turn, the variation is also important when measured on an annual basis, in the order of 3m. Fluctuating dynamism has an immediate correlation with the morphology of the landscape.
On the other hand, the chart allows you to record the dissociation between the river level and the level of rainfall in the region, because as 2.1 was analyzed, the Parana River is part of a network of tributaries South American scale. In turn, the large number of dams that have these tributaries plays a major role in setting tangible river level.
2.4 MORPHOLOGICAL ANALYSIS
Product of the constant change in the level of the river, studying the territory can be divided into three broad categories: Eventual floodable area of 48.65 km2 (with elevation of more than 5,1m level, but below the historic maximum of 6.45m.), frequently flooded area of 9.92 km2 (between 5.1 and 1.2 m.) and permanent water surface of 34.63 km2 (less than 1.2m.). It is noted that the whole territory can be under water before eventually grown very strong, so that all buildings must be high to be safe.
The water level directly influences the navigability (and thus access) of the territory, determining access to small ponds of ephemeral formation, or closing the passage thereof.
2.5 LAND USE, WATER ACTIVITIES
The survey of the different uses clearly shows the lack of coordination and planning, legislation and control. Broadly speaking, we can identify some main sectors: the Old Paraná (North sector) and Arroyo Lechiguana (North-Central sector) have the largest number of residences, some of them of great size, the Laguna Funnel (North sector) as recreational-sports center with a strong presence of sailing clubs of the city, the Banco San Andrés (South central), as facilities sector and Castellanos islands, French and La Paloma (South sector), with the highest concentration of fishermen houses and / or agricultural and livestock productive jobs.
Such generic distribution has clear correspondence with what happens in the margin of Rosario, both socially (understanding the North and Central as more prosperous than the South) and related to the presence of docks, marines and nautical clubs, which predominate in the north of the city.
2.6 CIRCULATORY FLOWS
Both margins (Rosario / Islands) are sewn together by a network of transverse circulations, which are strongly crossed by the longitudinal flow produced by large cargo ships in the navigation channel, with a depth of 32 feet draft. Mainly, navigation occurs with private boats for recreational purposes. The city has two public boarding platforms, Costa Alta in the northern sector of the city, near the Rosario-Victoria Bridge and the Fluvial Station in the city center, near the Monument to the National Flag. However they are only used for tourism purposes, at a high price, and serve to cross to the islands, but are not connected to each other.
2.7 FLORA AND FAUNA
The flora of the Parana Delta corresponds to species of various origins: subtropical, chaqueña, uruguayense and pampeano. The construction and destruction of islands, is due to the movement of the river level and the formation of different environments, with particular types of vegetables, which in turn are changing over time. The predominant plants are aquatic and marsh and start at banks and borders, favored by the waters with little strength and packed with sediments.
Delta fauna consists of species from different biomes. Its strategic geographical location makes it a receiver of all animal species are dispersed across the Parana and Uruguay rivers. Birds are distributed more easily, following, for example, forests that occur all along the great rivers, almost uninterruptedly, from Misiones to the banks of the River Plate. Mammals, amphibians and reptiles have used to reach these latitudes a natural means of transport: "camalotes" –aquatic plants.
3.1 DETECTION OF PROBLEMS
Being the preservation of the existing ecosystem the major concern of this investigation, the survey confirms and deepens the issues raised in the introduction. The legislative confusion leads to a lack of infrastructure in order to support and control different activities. These conditions determine a depletion of resources which, if not controlled in time, can become irreversible.
The development of a masterplan as ordering the intervention on the environment, trying to build a peaceful coexistence, is reaffirmed as the main objective of the work.
3.2 SECTORS OF OPPORTUNITY
_The Islands in the delta have infinite have a lot of programmatic opportunities, being a sine qua non condition to guarantee the preservation and development of the existing ecosystem. As a general strategy, it is understood that the concentration of specific programs can function as a counterpoint to the current "disorder" that is carried out from the disconnected sum of private initiatives without previous planning. For any type of project, it is mandatory a fluid transport system that generates a drive clear connection with Rosario, in order to be able to provide services and supplies to this sector.
_A Network of accessible and massive public nautical-transport would allow the development of new sectors and definitively get the entire population closer to the Parana River. A trip between the islands and the entire coast can be an enriching sensorial and cultural experience, a condition that today is a privilege that only few enjoy. Taking Venice as a case study, water is the flagship of its inhabitants, the city cannot be imagined without it, and people would not live without it. That kind of identification is what we should aim to achieve, especially with a river that is unique in the world in terms of size, flow and current.
_The programmatic concentration will allow the integration of Rosario with the system of islands of the Parana River, as well as generate new traffic flows able to bring together sectors that are unrelated today. Even the combination of different transportation systems can allow tour the city in north-south by the river and then with motor transport backbone east-west. Such a system would constitute a fully complementary investment to the existing city, and its integration with the overall driving-system will also allow coexistence with future projects to fruition as the implementation of metro or subway.
-Ley Nacional de Humedales Nº 23.919, 1991. Ley Nacional de Humedales Nº 25.335, 2000. Proyecto de Ley Nacional S-1628/2013.
-S. L. Casco, M. Neiff y J.J. Neiff 2009 - “Biodiversidad en ríos del litoral fluvial.” - Centro de Ecología Aplicada del Litoral. (CONICET) Corrientes 2009
-S. L. Castro, E. D. Cafaro, M. G. Gallego, A. M. Ravelli, J. J. Alarcón, C. G. Ramonelly y M. L. Amsler - Evolución morfológica histórica del cauce del río Paraná en torno a Rosario (km 456 – 406) - Facultad de Ingeniería y Ciencias Hídricas. Universidad Nacional del Litoral.
4.2 ILLUSTRATIONS CREDITS
Photographs: Walter Gustavo Salcedo
Drawings, Diagrams: Lab.Id
Boat Field Trips: Matías González Cid