The fire that lasted 40 hours and destroyed around 85% of the Juquery State Park, in the São Paulo municipalities of Franco da Rocha and Caieras, compromises the springs that supply the Paulo de Paiva Castro Dam, known as the Juquery Dam, at the top of the Cantareira System. The fire started on Sunday (22) and the Fire Department remained in place until Tuesday (24).
According to Pedro Luiz Côrtes, professor at the Institute of Energy and Environment at the University of São Paulo (IEE-USP) and coordinator of the International Network for Studies on the Environment and Sustainability (Rimas), the impact is not measurable yet. However, arson is one more problem affecting the water supply system.
This Wednesday morning (25), Cantareira is with 37.9% of its total volume. From yesterday (24) to today, the volume decreased by 0.2%, according to Portal dos Mananciais, of the Basic Sanitation Company of the State of São Paulo (Sabesp). With this, the system completed 14 days in a state of alert, when the volume of the reservoir falls below 40% of its totality. Juquery State Park is located within the hydrographic basin that makes up Cantareira.
“The events that occur within this area actually impact water security and system operation, especially in a fire situation, yesterday we had an important change in land use and occupation”, explains Guilherme Checco, research coordinator at the Democracy and Sustainability Institute. According to him, without the forest cover, the way water will be absorbed by that ecosystem “will be completely different”.
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Burial and silting
One of the consequences of the fire is the burial of the springs. Without forest cover, the soil is more susceptible to erosion during the rainy season, which ends up covering the area of springs and reducing their capacity to maintain an adequate volume of water. Another factor: without the forest cover, part of the rainwater, instead of being absorbed by the soil, ends up evaporating.
According to Cortes, instead of feeding springs, they evaporate and lose their capacity to feed rivers and reservoirs. This process also involves silting up of the dams.
“When it hits the soil directly, the rain runs off and carries part of the soil to the dam, due to the suppression of this vegetation cover. So the dam loses its storage capacity over time, due to the suppression of this vegetation cover that is in the surroundings”, says Côrtes.
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In addition to impacting the water system, the fire also destroyed the area that is considered the last remnant of Cerrado in the metropolitan region of São Paulo. Now, seven people are being investigated for releasing a balloon that caused the fire by the Civil Police and the Public Ministry (MP). “The case was registered as manufacturing, selling, transporting or releasing balloons and the police authority arbitrated bail, as required by law, which was paid and the man released,” reported the press office of the Public Security Secretariat (SSP).
Edition: Anelize Moreira