Overview

• Arsesp ordered Sabesp to reduce distribution pressure nightly from 19:00 to 05:00 across the metropolitan system and to manage pressure during the day to curb losses.
• Monitoring shows the Integrated Metropolitan System at about 32.8% of usable volume, with the Cantareira at roughly 29.7%, its lowest September level since 2015.
• Crossing the 30% threshold at Cantareira triggers an Agência Nacional de Águas rule that will reduce permitted withdrawals starting next month.
• Sabesp reports the first phase of nightly management, in place since August 27, saved about 7.25 billion liters, exceeding the target of 4 m³/s by reaching 4.2 m³/s.
• Officials say the current steps are temporary and focus on preserving reservoirs, and they acknowledge households without rooftop tanks may feel lower night pressure more acutely.