MATERIAL FACT - Form 6-K

MATERIAL FACT

Companhia de Saneamento Básico do Estado de São Paulo - Sabesp ("Company" or "Sabesp"), in compliance with Resolution 44 of the Brazilian Securities and Exchange Commission (CVM - Comissão de Valores Mobiliários), of August 23, 2021, hereby informs its shareholders and the market in general that, won the Public Tender No. 02/2023 of the Municipality of Olímpia, São Paulo State, with a fixed grant payment amounting R$ 148 million, for the provision of public water supply and sewage services for 30 years.

The municipality of Olímpia is 430km from São Paulo capital, with an estimated population of approximately 56 thousand people and has a full coverage of water and sewage service and will require the Company's operational, commercial, efficiency, and water loss efforts.

The concession demonstrates the Company's commitment to growth, and value creation with capital discipline, increased operational efficiency, and technology.

São Paulo, May 22, 2023.

Catia Cristina Teixeira Pereira

Chief Financial Officer and Investor Relations Officer