Cantareira System, in São Paulo, returns to alert state

The Cantareira System, the main reservoir in the metropolitan region of São Paulo, entered Band 3 – Alert in July. However, the situation does not foresee any change in the operation, informed in a note to Sabesp – sanitation company in the State of São Paulo.

Cantareira is part of the Integrated Metropolitan System – which is made up of six other water sources (Alto Tietê, Guarapiranga, Cotia, Rio Grande, Rio Claro and São Lourenço) – and currently operates at 54.7% of capacity, a level similar to 52, 2% registered in 2021.

Check out the Sabesp note in full

Sabesp informs that the Cantareira System entered Band 3 – Alert in July, according to the granting rules (Joint Resolution ANA/DAEE 925/2017). The situation does not foresee any change in the operation. The Company is currently withdrawing 22 m³/s, below the maximum authorized limit of 27 m³/s, which is possible thanks to the integration with other systems.

Sabesp clarifies that there is no risk of shortages at this time in the São Paulo Metropolitan Region, but guides the conscious use of water, at any time and in all the municipalities where it operates. The Company reinforces that Cantareira is part of the Integrated Metropolitan System, which also comprises 6 other water sources (Alto Tietê, Guarapiranga, Cotia, Rio Grande, Rio Claro and São Lourenço).

Since the water crisis, the Company’s investments have made the Integrated System more robust and flexible (it is possible to supply different areas with more than one system), with emphasis on the implementation of the new São Lourenço system and the interconnection of the Paraíba do Sul basin with Cantareira.

At the moment, the Integrated System operates at 54.7% of capacity, a level similar, for example, to 52.2% in 2021, when there were no problems in supplying the Metropolitan Region.

Hydrological Projection for the Cantareira System, from Cemaden, on May 3

This edition of the bulletin brings the situation for the month of April 2022, and hydrological projections for May to September 2022. The storage situation of the Cantareira System reservoirs, at the end of April 2022 (44%), is worse when compared to the same period in 2021 (51%).

With the current storage situation, the Cantareira System reservoirs are in the “Attention” operating range (storage between 40% and 60%)[1]whose maximum extraction flow to meet the water demand of the metropolitan region of São Paulo is 31 m³/s.

In April 2022, the average extraction for supplying the metropolitan region of São Paulo was 21 m³/s. Also in April, precipitation and flow were equivalent to 36% and 53% of the historical average for the month, respectively.

Regarding the projections, the simulations indicate that, in the historical average rainfall scenario, the inflow into the reservoir, from May to September 2022, for the same rainfall scenario, the inflow would reach 17 m³/s, the which represents 63% of the historical average for this period (27 m3/s).

Still considering the historical average rainfall scenario, the hydrological model projects a storage in the system, at the end of the projection horizon (September 2022), of 26%, in the “Restriction” operating range (storage between 20% and 30% ).

Considering a scenario of rainfall 25% below the average, the model indicates, for the same period, an average flow of 48% of the historical average and storage at the end of September, of 20% (“Special” operating range).