Plan defines restriction bands and works to guarantee supply, focusing on essential services and long-term monitoring
The government of São Paulo announced this Friday (24) a contingency plan for water supply in Greater São Paulo in the face of the risk of a new water crisis. The volume stored in the dams is at 28.7% of total capacity, the lowest level since the crisis of 2014 and 2015. This is the third consecutive year with below-average rainfall in the region.
The plan foresees gradual control measures, divided into seven bands, which define actions according to the level of the reservoirs: from reducing pressure in the pipes to rotation in extreme situations. Currently, the system operates in band 3, with nighttime pressure reduction for 10 hours.
Restriction ranges and measurements
- Band 1 (below 43.8%): review of basin transpositions and conscious use campaigns;
- Band 2 (below 37.8%): pressure reduction for 8 hours at night;
- Band 3 (below 31.8%): pressure reduction for 10 hours (current);
- Band 4 (below 25.8%): pressure reduction for 12 hours;
- Band 5 (below 19.8%): pressure reduction for 14 hours;
- Band 6 (below 9.8%): reduction for 16 hours, use of dead volume and emergency supply for essential services;
- Track 7 (level zero): supply rotation, alternating between areas, guaranteeing essential services and homes in vulnerable situations.
Band changes are defined after seven consecutive days of the index in the same category, and the return to the previous band occurs after 14 days. The rotation, considered an extreme measure, can only be authorized by the Arsesp Board of Directors.
Supply priority
In any restriction range, supply will be guaranteed to essential services and homes in situations of social vulnerability, including: hospitals, emergency care units, schools, shelters, police stations, prisons and the Fire Department.
Works to expand water supply
The government also announced works to increase water availability in the metropolitan region:
- Itapanhaú-Biritiba Interconnection: increase of 2,000 liters/second, completion scheduled for December 2025;
- Expansion of ETA Rio Grande: +500 liters/second, delivery in 2026;
- Expansion of ETA Cotia: +1,000 liters/second, delivery in 2026;
- Billings-Taiaçupeba Interconnection: +4,000 liters/second, completion in 2027.
According to Thiago Nunes, CEO of Arsesp, the focus is on long-term monitoring of reservoirs, following seasonality, and not just current levels. “Our concern is not with today’s stage, but with future behavior, ensuring that levels remain within the safety levels defined in the contingency curve,” he stated.
The measures have already resulted in savings of 25 billion liters in recent months, enough to supply cities such as Santo André, Mauá, Diadema and São Bernardo for two months. City halls in São Paulo have already declared a water emergency and are looking for alternative sources of water collection, while the problem also affects hydroelectric dams in the Rio Grande, responsible for 25% of the energy in the Southeast-Central-West, under monitoring by the ONS.
Published by Felipe Dantas
*Report produced with the help of AI
