2016 Results Economic-Financial Office and Investor Relations Office

Disclaimer This presentation may contain forward-looking statements referring to SABESP’s business outlook, operating and financial results estimates, and growth prospects. These are only forecasts, and as such, they are exclusively based on SABESP’s management expectation in relation to the future of business and its continuous access to capital to finance the Company’s business plan. These forward-looking statements largely depend on changes in market conditions, governmental rules, industry performance and the Brazilian economy, among other factors, in addition to risks exhibited in disclosure documents filed by SABESP. Therefore, they are subject to changes without prior notice.

Agenda Company Overview 1 Our Operations 2 Our Financial Performance 3 4 SPMR – Water Situation

Main Operational Indicators(1) One of the largest water and sewage service providers in the world… Company Overview Main Operational Indicators(1) Water Sewage Connections (million) 8.7 7.1 Coverage (%) 100 87 Treatment (%) 79(²) Billed Volume (m³ million) 1,990.3 1,552.2 Sabesp is one of the largest water and sewage service providers in the world based on the number of Customers Provides water to 24.7 million people and sewage services to 21.2 million people Also sells wholesale treated water to 5 municipalities (3.0 million people) Natural monopoly, low operating risk Serves the City of São Paulo and 365 out of 645 municipalities in the State Covers around 66% of State's urban population Operations in the São Paulo Metropolitan Region* represent 70% of our total revenues (1) As of December 31, 2016 (2) Treated sewage as percentage of collected sewage São Paulo Regional Systems Metropolitan Region *The Metropolitan Region we consider for this estimate, includes 8 municipalities outside the legal boundaries of the São Paulo Metropolitan Region and represents the municipalities served by the Company’s Metropolitan Division

Ownership Structure % (1) …with strong corporate governance We are a mixed capital company, majority-owned by the State of São Paulo, with significant private ownership State law requires the State of São Paulo to own at least 50% + 1 voting shares at all times Currently the Government of São Paulo has 50.3% share 100% common shares Market Cap: R$ 19.7 billion (as of December, 2016) Ownership Structure % (1) (1) As of December, 2016

Agenda 3 Our Operations 2 Our Company 1 Our Financial Performance 4 SPMR – Water Situation

Diversified customer base Water Billed Volume by Type of Customer Sewage Billed Volume by Type of Customer Passaremos a uma breve apresentação da nossa base de clientes A maior parcela das nossas receitas provem da nossa base de clientes residenciais, o que é muito positivo por se tratar de segmento de consumo estável e diversificado, diminuindo nossa exposição a um cliente individual Nossos clientes industriais e comerciais representam cerca de 30% de nossas receitas Nossa base de clientes residenciais tem crescido consistentemente, o que é refletido no crescimento de ligações de água e esgoto que cresceram respectivamente a taxas médias anuais de 2,8% e 4% nos últimos três anos Esse crescimento é justificado pelo crescimento vegetativo da população das cidades onde atuamos, bem como pela negociação de novos municípios, onde começamos a prestar os serviços de água e esgoto Over 80% of water volume comes from residential, commercial and industrial customer Over 90% of sewage volume comes from residential, commercial and industrial customer Water Revenues by Type of Customer Sewage Revenues by Type of Customer

Contract with the Municipality of São Paulo Broad coverage of municipalities Municipalities Nº of contracts % of revenue Renewed/Secured (Program and Service Contract) 281 80.3% Expired Contracts 54 12.2% To be expired (2017 - 2030) 34 6.7% Total Retail 369* 99.2% Wholesale 5 0.8% Total Sabesp 374 100.0% *Incluides 2 partial contracts with Mogi das Cruzes and Santa Branca with operations starting in 2017 Contract with the Municipality of São Paulo 30-year-service agreement between Sabesp, Municipality of São Paulo and State Government (expires in 2040) Minimum investment of 13% of the Gross Revenue, net of Cofins and Pasep Transfer of 7.5% of the Gross Revenue, net of Cofins and Pasep, to the Municipal Environmental Sanitation and Infrastructure Fund – to be recovered in tariff 8

Concession Power in Metropolitan Regions Regulatory Framework Obligatory creation of a Regulatory Agency  Municipal or State level Clarifies the payment conditions of non-amortized investments  up to 4 years Disbursement of federal funds conditioned to the existence of a sanitation plan Federal Law # 11,445/07  Federal Decree 7,217/10 and Federal Decree 8,211/14 Concession Power in Metropolitan Regions Legal proceedings related to this matter under Supreme Court (STF) appraisal were ruled in February 2013 Final decision released in September 2013: Sanitation services in metro regions are subject to shared responsibility between State and Municipality State Legislative has two years to adjust the legislation, create entities and mechanisms to implement the ruling Regulation activities and responsibilities include: Service quality Tariff structure and reviews Planning is a concession holder attribution ARSESP´s attribution

RABT = RAB0 + ∑(CAPEX+∆ CG-DEP) Tariff Revision RAB0 CAPEX + OPEX + IRCS + ∆ CG RABT = RAB0 + ∑(CAPEX+∆ CG-DEP) Volume (M3) P0  IRR = WACC (8.06%) ARSESP: Recent Resolutions / Public Consultation 03/31/16 Resolutions nº 640 e nº 641: ARSESP authorizes the cancelation of the Contingency Tariff and Consumption Reduction Incentive Program – Bonus  In effect since 05/01/2016 Arsesp discloses the RAB 04/11/16 ARSESP authorizes the tariff adjustment of 8.4478%  in effect since 05/12/16 06/30/16 Update of the Methodology and general criteria for the definition of SABESP’s Regulatory Asset Base  Start of the 2nd Ordinary Tariff Revision 08/30/16 Methodology Update and criteria for the definition of the RAB → ARSESP disclosed the Detailed Public Consultation Report 01/19/17 ARSESP approves the beginning of the 2nd Ordinary Tariff Revision and discloses the timeline for the 1st stage that will be performed as the following: First stage preliminary  June 2017 Second stage final  April de 2018 Timeline for the 1st stage of the 2nd Tariff Revision Stage No. Description Beginning Conclusion 1 Submission of the Business Plan by Sabesp Jan 23, 2017 Jan 31, 2017 2 Analysis of Sabesp's data Mar 31, 2017 3 Delivery of the Appraisal Report of the RAB by Sabesp 4 Validation of the RAB by ARSESP: reinforced base + partial incremental Apr 1, 2017 May 15, 2017 5 Receipt of SABESP's final data (historical) Mar 1, 2017 6 Development of the Initial Technical Note with Initial P0 and Weighted Average Cost of Capital (WACC) Apr 26, 2017 7 Opening of Public Consultation and Public Hearing - Initial Tariff P0 and WACC Apr 27, 2017 May 19, 2017 8 Analysis of the contributions received, development of the Final Technical Note and Detailed Report - Initial Tariff P0 and WACC May 22, 2017 Jun 8, 2017 9 Approval of the Final Technical Note, Detailed Report and Publication of the Resolution with the Preliminary Tariff P0 Jun 9, 2017 Jun 10, 2017 10

Tariff Adjustment and Revisions Annual tariff adjustment formula Productivity Factor (0.9386%) New Average Tariff = 1 Inflation (IPCA) 100 x Previous Average Tariff Quality Factor * - + * Not yet defined ARSESP’s Adjustments and Revisions Sabesp’s Formula ETR – Extraordinary Tariff Revision IPCA – Amplified Consumer Price Index as of Mar/16

Water and Sewage Operations Water Connection Evolution (million) Water Coverage (Connections in ´000s) Add 1.0 million new connections by 2022 Passaremos a uma breve apresentação da nossa base de clientes A maior parcela das nossas receitas provem da nossa base de clientes residenciais, o que é muito positivo por se tratar de segmento de consumo estável e diversificado, diminuindo nossa exposição a um cliente individual Nossos clientes industriais e comerciais representam cerca de 30% de nossas receitas Nossa base de clientes residenciais tem crescido consistentemente, o que é refletido no crescimento de ligações de água e esgoto que cresceram respectivamente a taxas médias anuais de 2,8% e 4% nos últimos três anos Esse crescimento é justificado pelo crescimento vegetativo da população das cidades onde atuamos, bem como pela negociação de novos municípios, onde começamos a prestar os serviços de água e esgoto Sewage Connection Evolution (million) Sewage Coverage (Connections in ´000s) Add 1.3 million new connections by 2022 Collection: 93% in 2021 Treatment: 83% in 2021

Capex Plan of R$ 13.9 billion from 2017 to 2021 3,900* Financial Value (R$ million) 2,136** Main Programs Metropolitan Water Program Tietê Project Corporate Program for Reduction of Water Loss Clean Stream Program Clean Wave Program (*) Book Value – Includes non-cash items (**) Book Value – Items that affected cash - Additional information is presented in Note 30 of the 2016 inancial Information

Investment Plan – Financing 2017 to 2021 – R$ 13.9 billion BNDES R$ 1.3B CAIXA R$ 1.1B BID R$ 580MM JICA R$ 350MM BIRD R$ 70 MM FINEP R$ 40 MM CAIXA

Agenda Our Company 1 Our Operations 2 Our Financial Performance 3 4 SPMR – Water Situation

Long term and low cost funding Total debt breakdown Total debt by currency (*) IDB 713 agreement Debt amortization profile (R$ million)

Consistent performance Net Revenues (R$ million) Net Income (R$ million) Adjusted EBITDA (R$ million) Dividends/Pay Out   2010 2011 2012 2013 2014 2015 2016 Dividend Declared (R$) 2.00 2.54 2.35 0.78 0.37 0.22 1.20 Pay Out % 27.9 47.3 Outstanding Shares (million) 227.8 683.5 Adjusted EBITDA Ajustado – Last 12 months Adjusted EBTIDA Margin – Last 12 months Adjusted EBITDA Margin Without Construction – Last 12 months

Historical leverage metrics (R$ million) Adjusted Total Debt vs. Adjusted EBITDA* Adjusted EBITDA* vs. Financial Expenses** Adjusted Total Debt = Total Debt - Interest Net Debt vs. Adjusted EBITDA* Net Debt vs. Equity * Adjusted EBITDA – LTM ** Financial Explosures paid - LTM Calculated in accordance with CPCs/IFRS

Covenants – Total Adjusted Debt vs EBITDA

Financial Highlights (R$ million) * In accordance with CPCs / IFRS, which includes Construction Costs. ** R$ / 000 shares

Agenda 1 Our Company 2 Our Operations 3 Our Financial Performance 4 SPMR – Water Situation

Cantareira System – Rainfall (mm) OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP Historical avg. 130.8 161.2 226.8 265.9 206.5 184.1 89.2 83.2 56.0 49.9 36.9 91.9 Historical low 21.4 52.4 104.5 111.8 40.2 55.8 7.6 8.8 0.0 0.1 0.9 2016/17 175.3 170.8 158.4 393.1 94.2 113.4 Oct-Feb Média: 991.2 mm Mínima: 330.3 mm 2013/14: 444.1 mm 2014/15: 813.6 mm 2015/16: 1.058.3 mm 2016/17: 991.8 mm March 2014: 193.3 mm 2015: 189.9 mm 2016: 179.6 mm March, 23rd 22

75% of Historical Average Inflow Cantareira System – Water inflow (m³/s) Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Historical avg. 30.6 35.0 53.1 70.9 73.9 66.9 48.4 38.4 35.3 28.8 24.5 25.6 Historical low 14.0 21.8 26.9 27.6 28.1 24.7 19.9 16.5 13.9 12.0 11.8 1953 17.5 26.0 31.5 34.5 29.8 34.6 23.8 20.7 17.6 16.3 16.2 2013/14 25.1 22.1 22.5 15.4 10.5 18.9 17.2 10.1 10.0 6.4 8.2 9.0 2014/15 5.2 8.8 16.0 11.5 40.7 42.6 18.1 11.3 5.8 18.3 2015/16 14.8 27.1 52.3 73.8 49.6 69.8 24.1 25.0 62.9 19.4 19.3 15.3 2016/17 24.2 29.5 30.2 76.0 36.4 42.9 Historical Average Inflow October-January: 52.7 m³/s Inflow (Oct-Jan) 1953 : 27.3m³/s Inflow (Oct-Jan) 2013/14 : 19.1 m³/s Inflow (Oct-Jan) 2014/15 : 16.4m³/s Inflow (Oct-Jan) 2015/16 : 43.5 m³/s Inflow (Oct-Jan) 2016/17 : 39.3 m³/s Inflow Oct-Jan/17: 75% of Historical Average Inflow March, 23rd 23

Water Monthly Production – SPMR vs Cantareira (m³/s) March, 23rd 24

Current operating volume as of June, 7th , 2013 Operating volume available at SPMR’s Reservoirs Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Current operating volume as of June, 7th , 2013 March, 23rd 25

Water Plan for the SPMR – 2015 to 2019 (main initiatives) 26

www.sabesp.com.br IR Contacts Mario Azevedo de Arruda Sampaio Angela Beatriz Airoldi Head of Capital Markets and Investor Relations Investor Relations Manager maasampaio@sabesp.com.br abairoldi@sabesp.com.br +55 (11) 3388-8664 +55 (11) 3388-8793