Water and Waste Services Regulation Authority - ERSAR (Portugal)


Regulatory Model

In Portugal, there is a regulatory agency, the Water and Waste Services Regulation Authority (ERSAR), which according to its statutes, exercises important regulatory functions over all operators of mainland Portugal in WWS and urban waste. Its primary duty is the protection of customer rights and the safeguarding of sustainability and economic viability of the systems. As a national authority, ERSAR also has the duty of monitoring and controlling the drinking water quality for all the operators in mainland Portugal. ERSAR adopted the sunshine regulation model as the main method of quality of service regulation, which is based on the published results of the performance of regulated operators. To this end, it publishes in an annual report, the performance results of operators, obtained from a set of performance indicators.More recently additional powers were attributed to ERSAR, namely in a stronger intervention in the adoption by municipalities of adequate tariff structures. Law No. 379 of 1993, Law No. 147 of 1995, and Law No. 58 of 1998 provide the main legal framework for WWS regulation in Portugal.

Market Structure

The ownership and management of the WWS is mainly in the public sector. The private sector provides WWS to less than 20% of the population. The WWS are mostly deverticalised, i.e. the wholesale and end-user systems of the WWS are provided by separate entities. In horizontal terms, the operators have a low degree of integration, and even without considering the some micro entities which operate in very small areas (some with less than 50 en-users), there are around three hundred operators for ten million inhabitants. Regarding available services, the operators almost always provide WWS together, frequently including the services of urban waste and, less frequently, other activities. There are only a limited number of operators that individually provide the service of water or wastewater.

Tariff Setting

The tariff system adopted by operators usually consists of a fixed part and a variable part based on the volume of water consumed. There are special tariffs for large families (in a small number of cases), for social service institutions and low-income customers (quite generalized throughout the country). Domestic and industrial customers are charged distinctly and there is cross-subsidisation between them. The regulator has involvement in the definition of both bulk and retail tariffs.

Quality of Service

Overall, the WWS provide a high quality of service. To encourage quality of service between the operators, ERSAR performs an annual benchmarking exercise, which analyzes compares and publishes the performance of all operators. This exercise is published in an annual report which has fostered a favourable evolution of the quality of service. Some of the aspects where improvement is more imperious are unnaccounted-for water, energy efficiacy and infrastructure rehabilitation.

The Regulator


Legal basis

Law no. 10 of 2014

Number of employees

66 employees


8 million Euros (2014)


ERSAR – The Water and Waste Services Regulation Authority
Rua Tomás da Fonseca, Torre G - 8º, 1600-209 Lisboa, Portugal
Tel: + 351 210 052 200
Fax: + 351 210 052 259

Email: geral@ersar.pt
Website: http://www.ersar.pt

Relevant Entities

Portuguese Environment Agency

Operators’ Association

State Holding of Water Companies

Ministry for the Environment, Spatial Planning and Energy

The Sector


Service Coverage

Number of operators

Ownership and management of services

  Ownership Management
  Pub. Priv. Pub. Priv.
Water 100% 0% 82% 18%
Wastewater 100% 0% 82% 18%

Volume of activity

Economic and financial data

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