São Paulo Reservoirs Sink to 26% After Eight Straight Days of Heat-Driven Declines

Overview

• The Integrated Metropolitan System fell to 26.1% usable capacity on Dec. 29, its lowest December reading since the 2015 crisis, with Alto Tietê at 19.7% and Cantareira near 20%.
• A record heat wave pushed São Paulo to 37.2°C on Dec. 28 and lifted water demand by up to 60%, forcing production up to 72 m³/s despite an estimated holiday drop in consumers.
• Under Arsesp’s contingency plan, the region remains in faixa 3 with Sabesp reducing network pressure for 10 hours nightly from 7 p.m. to 5 a.m.
• The state reports 57 billion liters saved from Aug. 28 to Dec. 16 through pressure reductions, while officials caution that relief depends on rainfall that has been scarce.
• Local supply strains persist, with low pressure and outages prompting water trucks in cities like Tatuí and Tietê, and the Paraopeba system in Greater Belo Horizonte operating at 46.6% with irregular service in some areas.