Guaíba – river or lake?

Guaíba River (Porto Alegre/RS) after intense rain. Photo: Gilvan Rocha/ Agência Brasil


It is important to legally define whether the Guaíba is a river or a lake for the purposes of effective implementation of public policies to protect its banks

A controversy that precedes the extreme weather event that hits Rio Grande do Sul tends to emerge with more intensity soon after the resumption of normality on the edge of the Guaíba estuary, mainly when the discussion about planning the reconstruction of cities and the limits takes place. of use of the banks of this great river or lake that beautifies and brings joy to the city of Porto Alegre. This is the complex discussion about whether the Guaíba is a river or a lake?

The controversy began with the publication of the Porto Alegre Environmental Atlas, which contains evidence that points to the likelihood of Guaíba being a lake and not a river. The characterization as a lake has been defended by those who advocate the use of the banks of the Guaíba to carry out various economic activities because the Permanent Preservation Area – APP for lakes is smaller in size than that established for river banks.

The Guaíba in some sections has the characteristics of a lake and in others of a river, therefore, defining the Guaíba, precisely, as a river or a lake is absolutely impossible. However, it is important that this conflict is legally clarified for the purpose of effective implementation of public policies to protect its banks in the face of the “new normal”, caused by extreme weather events, such as the one we are experiencing.

As for the legal aspects related to this controversy about whether the Guaíba is a river or a lake, there is no need for any concern regarding the legal protection of this common good. It is noteworthy that this environmental good falls into the category of common goods because it is neither private property nor state property, but rather a good for everyone, for the entire community.

It is necessary to clarify the expressions of concern with the treatment that Brazilian legislation provides for the preservation of lake banks that are smaller in width than river banks. They point out that if the Guaíba is defined as a lake, the Permanent Preservation Area of ​​its banks is only 30 meters and if it is defined as a river, it is 500 meters for stretches where the width is greater than 600 meters.

It is essential to explain that the Forest Code considers a Permanent Preservation Area, in rural or urban areas, to be the marginal strips of any watercourse, with a minimum width of 30 to 500 meters, on an increasing scale depending on the width of the watercourse. , being 30 meters for watercourses up to 10 meters wide and 500 meters for watercourses wider than 600 meters.

In the same article 4, the Forest Code considers Permanent Preservation Areas to be the areas surrounding lakes and ponds with a minimum width of 30 meters in urban areas and 100 meters in rural areas, which will be 50 meters when the body of water is up to 20 hectares of surface.

According to the rules stipulated in Brazilian legislation, the banks of any watercourse are areas that must be permanently preserved. Therefore, it is of fundamental importance to verify the concept of watercourse and which types of water bodies are covered by this concept. Legally, the term watercourse was defined by the 1997 New York Convention, in its article 2, as “a system of waters that, by virtue of their physical relationship, constitute a unitary whole and normally flow to a common point of arrival” , and the International Law Commission linked to this Convention interprets that the “water system” comprises flowing waters from rivers, lakes, aquifers, glaciers, canals, etc.

Therefore, a watercourse is a flowing water body that flows into another water body, that is, any flowing body of water, such as rivers, streams, streams, among others. Thus, running waters in lakes are watercourses and must have their banks protected at the same width as other watercourses.

Furthermore, the Brazilian legislator uses in the Forest Code the expression “body of water” and not water course to refer to lakes and lagoons when stipulating the width of the Permanent Preservation Area, in a clear demonstration that the minimum width of 30 meters of protected margin, in urban areas, is only for lakes and ponds with dormant waters.

However, if the lake has running water, as is the case with the Guaíba River/Lake, the rules that must be observed are those stipulated for watercourses, therefore, the margin must be preserved within a range of 500 meters. width in sections where the Guaíba is more than 600 meters. Furthermore, the difference made by the legislator in establishing a greater width for the banks of running waters than the banks of dormant waters is because technical data points in this direction, for better preservation of these environmental assets.

Finally, in the event of interpretative conflict and non-acceptance of the semantic interpretation made here, the argument still remaining as an alternative to better preserve the water banks of this important watercourse is that when in doubt between defining the Guaíba as a river or as a lake, that is, to preserve 500 or 30 meters, the Principle of Environmental Law can be used, with precedents from the Superior Court of Justice, “in dubio pro natura”which consists of using, in case of doubt, the standard that is most beneficial to the environment.

*João Hélio Ferreira Pes Professor of Law at the Franciscan University – UFN (Santa Maria, RS). Author, among other books by Privatization and commodification of water (Dialectic).

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