The Cantareira system can reach April 2022, beginning of the next dry period, with 10% of its capacity, according to the most recent projection by Cemaden (National Center for Monitoring and Alerts on Natural Disasters).
The percentage is expected in the most pessimistic scenario, if the rains 50% below the historical average for the period. If precipitation is as expected, Cantareira will arrive in April with a volume of 65%, according to the agency.
The projection represents a worse situation than that recorded in 2011, the year before the water crisis in Greater São Paulo, according to the professor of the postgraduate program in environmental science at the Instituto de Energia e Environment (IEE) at USP, Pedro Luiz Côrtes. “We have a climate forecast of a summer with below-average rainfall that has been confirmed despite an early rainy spring”, he says.
According to him, enter 2011 and 2020, Cantareira presented a rainfall deficit in relation to the historical average, with the exception of 2015, when there was 5% of surplus in supply.
Even so, Côrtes does not rule out the possibility of Cantareira recovering as a result of the summer rains, albeit short. “After the rainy season, the of the reservoir tends to fall a lot.”
In a statement, Sabesp (Basic Sanitation Company of the State of São Paulo) stated that there is no risk of shortages in the metropolitan region of São Paulo at this time “The projection points to satisfactory levels of the reservoirs with the prospect of rain in late spring and early summer, when the situation will be reassessed”, he informed.
The reservoirs that supply the region São Paulo metropolitan area received this year, between January and October, on average 25% less rain than in the same period in 2011, the year before the water crisis.
According to the head of the Applied Research Service at Inmet (National Institute of Meteorology), meteorologist Danielle Ferreira, the forecast for the next few months are below average rain, between 5 and millimeters less than normal for the period. “The rains will occur, but not enough to make up for the months of waiting. and the last summer is drier than expected”, he says.
The same forecast is made by Climatempo meteorologist Ana Clara Marques, who predicts between 17% and 25% less rain in Greater São Paulo between October and March of next year. “The biggest concern is with the next dry period, starting in June 2022, when the reservoirs may be below the expected volume”, he says.
Since 2018, when necessary, Sabesp supplies Cantareira with water from the Paraíba do Sul river basin after completion of the works on the Jaguari-Atibainha interconnection and the São Lourenço system.