The Pantanal and the Paraguay
River Basin: From the Technical Focus to the Political Option
(Excerpts from the full paper presented in the
uncorrected, advance proof of The Pantanal of Brazil,
Bolivia and Paraguay, Hudson MacArthur Publishers, copyright 2000
by Waterland Research Institute)
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The confluence of the Paraguay-Paraná aquatic
system with three surrounding ecosystems, the “Selva Amazónica,”
the “Cerrado” and the “Gran Chaco,” facilitates an extraordinary biotic
interchange, creating an impressive biodiversity which endures at present
but which runs a serious risk of diminishing. Today, experts and political
leaders throughout the world are focusing their attention on this ecosystem
— or, more correctly, on this collection of ecosystems — with the intention
of it becoming an object of sustainable development that is compatible
with the preservation of its ecological character.
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However, it is too rarely emphasized that the
Pantanal should not be considered in isolation but rather as forming part
of the Paraguay River Basin and, even moreso, the larger La Plata Basin.
The “El Gran Pantanal” should be studied, preserved and managed in relation
to this larger region --- an expanse which encompasses more than 2 million
square kilometers and a population of more than 100 million inhabitants,
and extends through Brazil, Bolivia, Paraguay, Argentina and Uruguay. This
is a natural unity that transcends the borders between nations. This is
the only focus technically correct; it should be politically expressed
in an agreement of a super-national or intergovernmental nature, among
nations of the macro region.
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The Pantanal is located in the extreme north of
a type of fluvial vertebral column, more than 3,800 kilometers long, which
consists of:
– the Upper Paraguay, from the Paraguay
River’s origin until its confluence with the Apa River (1,670 km);
– the Middle Paraguay, from the Apa River to Itapirú,
47 kilometers to the south of Asunción, Paraguay (584 km);
– the Lower Paraguay, between Itapirú and
the Paraguay River’s confluence with the Paraná River (350 km);
– the Middle Paraná, from the Paraná
River’s confluence with the Paraguay River to Santa Fé, Argentina
(650 km);
– the Lower Paraná, from Santa Fé
to the Río de la Plata estuary (600 km).
Each of these sections delineate regions with distinct
ecological attributes. Despite the differences, however, a marked interdependence
exists among the regions, such that environmental impacts that originate
in the extreme north can influence even the Río de la Plata estuary,
and incidents in the lower sections can influence the biogeographical characteristics
of the Pantanal. This interdependence is not irrelevant for either the
regulation of the river flow or the preservation of biodiversity. For example,
if the Pantanal were to lose or diminish in its capacity to be a “sponge,”
in that it serves to reduce the flow of the water that enters the upper
part of the basin, the consequences could be grave. Currently, the crest
or river swelling that issues forth from the headwaters of the Paraguay
River arrives in the lower Paraguay after some six months delay. The river
crest that impacts upstream in the Pantanal in February impacts the lower
Pantanal in July. If the annual cycle of flood and drought, increase and
decease is altered, what would happen to the fauna and flora in the lower
Paraguay?
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The Paraguay-Paraná Hidrovia Project has
contributed to our knowledge of the area by showing the interdependence
of the distinct regions that form parts of the basin. These environmental
impact studies have confirmed in dramatic fashion some of the dangers that
lie in wait for the basin (Taylor et al. 1997). Developing a system for
navigation that is 3,440 km long (from Cáceres, Brazil to Nueva
Palmira, Uruguay) will include deep dredging, the establishment of canals,
excavation of rocky beds, realignment of channels and, moreover, the improvement
of port and roadway infrastructures. Various alternatives exist with respect
to the intense alterations entailed in the Hidrovia Project. The most comprehensive
alternative, presented in 1996 by the firm Hidroservice Louis Berger in
Asunción, anticipates the formation of:
• Canals 100 m wide, 3 m deep for the
Santa Fe-Asunción section.
• Canals 90 m wide, 2.6 m deep for the Asunción-Corumbá
section.
• In the Corumbá-Cáceres section,
within the Pantanal, segment A, from Corumbá to Lake Gaiba (Laguna
Gaiba in Bolivia; Lagoa Guaiba in Brazil), would not be the object of major
intervention. In segment B, from Lake Gaiba to Bacia de Bracinho, strong
interventions would be necessary to widen and straighten out the curves
and meandering. In segment C, from Bracinho until Cáceres, there
would have to be dredging to deepen the river beds. In broad outlines,
in segment B there would be 78 strong interventions, and in segment C dredging
would be necessary to deepen the waterway in 64 critical straits. Also,
the works required in the Santa Fe-Corumbá section would be considerable:
92 dredging operations to deepen the channel, 12 dredging operations to
correct critical curves, and 23 straits of rocky bottom, in which eight
would require the removal of rocks.
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Various evaluations have noted that such alterations
would have diverse types of environmental impacts, as much a result of
the construction of the Hidrovia as during its operation.
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Modifications in the Pantanal would negatively
impact wetlands of significant biological importance that are situated
in the lower sections of the Paraguay River. For this reason, Paraguay
is very interested in avoiding damage to the Pantanal, not only for the
sake of the Pantanal proper, but because what originates in the Pantanal
will affect the wetlands of the lower Paraguay that constitute a 2.5 million
hectare
(25,000 km2) sanctuary, consisting of great riches in animal and plant
species. Although there continues to be an interest in developing a regular
navigable passageway from the Atlantic to Asunción, Paraguay desires
that such be realized only while reducing to a minimum any negative environmental
impact. All of the previous is situated in a macro regional context, where
there is strong attention to the environment because of deforestation,
erosion, overhunting and overfishing. This all points to the necessity
of achieving an integrated basin management of the Paraguay and Paraná
Rivers.
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In the manner of an example, listed below
are critical areas that should be the subject of integrated basin management,
since these areas relate closely to the objectives of both development
and ecological preservation of the Pantanal.