São Paulo Unveils Seven-Tier Drought Plan as Cantareira Hits Lowest Level Since 2016

Overview

• State regulator Arsesp activated a seven-level contingency that scales up to 16 hours of reduced pressure and, in the worst case, rotating supply interruptions.
• Greater São Paulo is currently in Tier 3, which enforces 10 hours of nightly pressure reduction, with any escalation requiring seven consecutive days at a lower threshold and easing after 14 days of improvement.
• The Cantareira system fell to 24.2% of usable storage and the metropolitan system to 28.7%, the weakest levels since 2016 according to Sabesp.
• Operational steps already in place include cutting Cantareira withdrawals from 27 m³/s to 23 m³/s and maintaining nightly pressure reductions; ANA also authorized transfers from the Paraíba do Sul basin, and emergency local permits were issued such as in Mairinque.
• Low levels at hydro reservoirs in the Rio Grande basin prompted closer ONS monitoring, with the operator warning that more thermal generation may be needed, raising system costs.