The Sistema Cantareira water supply system has entered an alert level as reservoir storage fell to 39.9% of total capacity [1].
This decline threatens the water security of the Greater São Paulo region, including municipalities such as Santo André and São Caetano do Sul. Insufficient summer rainfall left the reservoirs at critically low levels, raising the risk of a water crisis during the drier autumn months [3, 5].
The system, overseen by the Agência Nacional de Águas (ANA) and the Agência de Águas do Estado de São Paulo (SP Águas), reached the "faixa 3" alert classification on May 30, 2024 [1, 2]. This represents the worst first-semester water level index recorded since 2022 [5]. Some reports indicate this is the lowest level seen in a decade following a summer season [6].
There are conflicting reports regarding the current status of the system. While some data suggests the system entered the alert level in late May, other updates indicate it remained in "faixa 2," or the attention level, throughout June 2024 [4].
Despite the current fluctuations between attention and alert levels, officials have signaled a move toward stricter measures. The system is scheduled to enter the "faixa de restrição," or restriction level, starting Oct. 1, 2024 [3]. This transition would implement more aggressive water-saving mandates to prevent total depletion.
Local authorities continue to monitor the reservoirs as the region navigates the seasonal dry spell. The current instability in water levels highlights the vulnerability of the metropolitan area to erratic rainfall patterns, a trend that has plagued the region's infrastructure for years.
“Reservoirs at 39.9% of total capacity”
The descent of the Cantareira system into alert and impending restriction levels underscores a growing instability in Brazil's urban water management. By triggering these stages, authorities are attempting to preempt a full-scale crisis through managed rationing, but the decade-low levels suggest that historical rainfall patterns are no longer reliable for maintaining the region's primary water source.
