Measure authorized by the state government responds to critical levels of the reservoirs, which operate with only 38.4% of the total capacity
Sabesp (São Paulo State Basic Sanitation Company) will start reducing water pressure for 8 hours per day at the night in the São Paulo Metropolitan Region. The measure was authorized by the state government on 3rd (26.ago.2025) in response to the critical levels of reservoirs, which record only 38.4% of its total capacity, the worst index since the 2015 water crisis. The action aims to save approximately 4,000 liters of water per second during the current drought.
The authorization to reduce water pressure is part of contingency actions implemented by the São Paulo government to face water scarcity. Sabesp may apply the measure for 8 hours per day, at a break to be defined by the company itself.
From the authorization of (Regulatory Agency of Public Services of the State of São Paulo), Sabesp will define the exact time when pressure reduction will be applied. The measure is expected to contribute to preserving reservoir levels until spring rains can recompose the springs.
Greater SP’s springs have a constant drop in recent years. By 2023, reservoirs operated with 72.5% of capacity. The index fell to 59.6% in 2024 and arrived in August this year by 38.4%, which represents a reduction of 34.1 percentage points in 2 years.
The more severe than normal drought for the winter period is the main cause of decrease in reservoir levels. The weather data indicate that August will end with precipitation far below historical averages. Projections indicate that rains should gain enough intensity to reverse the downward trend from the 2nd half of September, with early spring.
The Cantareira system, considered the largest in the region, currently works with only 35.9% of its capacity. With daily loss of approximately 0.3 percentage point, its useful volume can only be 15% at the beginning of the rainy season.
Alto Tietê has 30.5% volume stored and recorded only 2.5 mm of rain in August, when the average for the month would be 30 mm. Guarapiranga operates with 55.3% of capacity, having received only 4 mm of precipitation in the month, well below the historical average of 39.8 mm.
The Cotia system has 60.1% of stored volume, with monthly rainfall of only 3.6 mm, against a historical average of 40 mm. In Rio Grande, which has 59.2% of its capacity, only 8.2 mm of rain were recorded in August, when the average for the month is 48.4 mm.
Rio Claro was the system that recorded the highest volume of rainfall so far, with 25.4 mm, still far below the record average of 100.1 mm, operating with only 23.2% of its capacity. São Lourenço, with 56.6% storage, received only 2.8 mm of precipitation, when the average for the period is 60.7 mm.
