The relationship between riparian forests and flood control can be explained through several mechanisms. Because it has dense vegetation, made up of trees, shrubs and other plants, this area acts as a natural barrier, absorbing rainwater and reducing the amount of water that drains directly into the rivers. It is also capable of slowing down the flow of water moving across the soil surface, which allows for more efficient water absorption.

Plant roots in riparian forests help stabilize the soil, reducing erosion. More stable soil means less sediment being transported into waterways, which contributes to flood prevention. During periods of intense rain, vegetation temporarily stores water, gradually releasing it over time. This helps keep river levels more balanced, reducing flood peaks.

The destruction or reduction of riparian forests can compromise these ecosystem services, increasing vulnerability to floods and their increasingly frequent and severe impacts linked to climate change. For this reason, the preservation and restoration of riparian forests are essential measures for the sustainable management of river basins and for reducing the risk of flooding. Awareness and compliance with environmental laws that protect permanent preservation areas are essential to guarantee these benefits.

 

Riparian Forest: its importance and preservation

Known for being the vegetation that accompanies watercourses, springs and reservoirs, the riparian forest receives this name due to its main function, which is that just as eyelashes protect the eyes, they are the protectors of water, soil, biodiversity and of the entire ecosystem that accompanies its delimitation, in addition to playing a crucial role in controlling floods and maintaining water quality.

With deforestation and fragmentation, due to agricultural and urban expansion in recent centuries, the Brazilian Forest Code was created in 1934 and, over time, has undergone several revisions and updates, with the main objective of establishing rules and standards for the use and preservation of forests and other forms of native vegetation in Brazilian territory. Riparian forests are protected by the Brazilian Forest Code, which requires the maintenance of a strip of vegetation along the banks of water bodies.

Permanent Preservation Areas (APP) vary according to the type of watercourse and the characteristics of the terrain. For example, the Rio de Peixe, which passes through Socorro, has strips over 10 meters wide, so it should have some stretches of APP measuring 50 meters. When this does not occur, that is, when the APP strip presents some consolidated activity (APP area or Legal Reserve that was deforested and has some type of agricultural production, tourism and construction activity prior to July 22, 2008, and since that practices soil and water conservation), the law requires that the original vegetation be recovered in at least part of the area. The amount of area varies depending on the size of the property and where it is located.

In Brazil, the Fiscal Module was established, which is an agrarian measurement unit used to determine the size of rural properties. Each municipality defines the value of the fiscal module, considering factors such as soil type, climate and regional characteristics. In Socorro, 1 fiscal module corresponds to 16 hectares of land. With this, it is possible to establish, together with the Forest Code, that in Socorro, a rural property that has up to 1 fiscal module, must restore 5 meters of APP on each side for streams and rivers up to 10 meters wide. See the graph below for Socorro/SP:

Graphic: Copaíba Environmental Association

 The figure below illustrates the minimum area to be recovered from riparian forest, with native forest (let it grow or plant), for rural properties with up to 1 fiscal module, being 5 meters of forest on the banks of both sides of the stream/river and 15 meters around the source:

Figure: Copaíba Environmental Association

 

To comply with the Brazilian Forest Code, the rural owner must register with the CAR (Rural Environmental Registry) and the PRA (Environmental Regularization Program). If you have any questions or guidance on registration, contact Socorro: Casa da Agricultura – Av. Dr. Rebouças, 116 – Centro / (19) 3855-3178, or via the website: www.car.agricultura.sp.gov.br