Autumn commenced on Friday, March 20, with the water supply level of the integrated system serving the Greater São Paulo area at a mere 56% capacity, the lowest in a decade according to data from Sabesp. This figure is just slightly better than the 46% recorded at the start of the dry season in 2016. At the onset of summer last December, the integrated system--which consists of seven reservoirs, including Alto Tietê, Cantareira, and Guarapiranga, among others--was critically low at only 27% capacity.

The rainy season during the summer in Greater São Paulo contributed to a partial recovery of water levels in the reservoirs supplying the capital. This recovery was notably driven by the Guarapiranga reservoir, which is currently at 93% capacity, alongside other reservoirs like Billings. Despite this positive trend, the Cantareira system, which serves around 8.8 million people in the region, remains below the desired operational level, raising concerns about the sustainability of water supply as dry conditions are expected moving into the autumn months.

As the region navigates this critical situation, it reflects broader trends of water management challenges faced in urban settings due to climate variability and historical changes in rainfall patterns. The authorities and water supply agencies are likely to be under pressure to implement stricter water usage regulations to ensure equitable distribution and long-term sustainability, particularly as the dry season progresses and demand remains high.