Dec 18, 2014

Urban Water and Sanitation Sector in Chile

During the 1980s, the sector was dominated by governmental water-supply utilities, which supplied water and sanitation (WSS) services to most of Chile.  The inclusion of private operators began in 1988.  The urban water supply coverage in 1993 was 97.6%, and the service was provided mainly by state owned water supply operators (see Figure 1).  Furthermore, only 85.9% of urban population had access to sewer collection and only 13% of wastewater was treated. The driver of this situation was the low investment in infrastructure; the estimated investment cost deficit for the 1993 – 2000 period was $2.4 billion.  A 63% of the deficit was in wastewater treatment.  Before 1993, the average annual investment of the state owned operators was $150 million. 

Figure 1: Growth and Evolution Regulated Water and Sanitation Sector (Own elaboration based on SISS, 2013)

During 1994, several of the 13 state owned WSS operators presented losses; for example Essat presented -4.1% and Emssa -3.2%.  This was, in part due to a 30% increase in average costs between 1990 y 1994. Administrative costs increased during this period; ESVAL incremented its administrative costs in 140% while EMOS increased by 40%. Furthermore, non-revenue water varied between 24% and 43%. 
The actual legal framework of the WSS sector established in 1988, establishes the following objectives that water and sanitation tariffs must satisfy:
a)      Full recovery of operation and maintenance costs;
b)      Fund necessary infrastructure reposition and development plan investment;
c)      Tariff reductions when operators increase efficiency; and
d)      Operational margins that are consistent with the opportunity cost of capital.

The legal framework of the Chilean water and sanitation tariff system establishes that tariffs must satisfy the principles of i) economic efficiency, ii) water conservation incentives, iii) equity, and (v) affordabiliy (Chavez, 2002).

In order to comply with economic efficiency, the WSS tariffs are based on a two Part Tariff, following Coase’s Solution: a variable and fixed tariff. The variable tariff is set following Hotelling’s Principle; thus, variable water tariff is consistent with the first best solution where marginal benefits are equal to long-run marginal costs[1] (MC) and social welfare is maximized (Figure 2).  However, this variable tariff set at MC does not cover the operator’s average costs; that is, the WSS providers operate with losses.  In order to satisfy the full cost recovery principle, a fixed tariff is included so as to cover the natural monopoly’s losses at the first best solution. 

Figure 2: Tariff setting Principles

The Executive Decree 453 of the 1988 Law N° 70, of the Ministry of Public Works (Ministerio de Obras Públicas, MOP) establishes a variable tariff which is set for periods of high demand, during summer months, (peak variable tariff $/m3) and for non-peak periods (non-peak variable tariff $/m3). The peak and non-peak tariffs are considered so as to internalize changes in seasonal demand and thus cover differences in the provision costs of the service. As previously pointed out, the current tariff structure also considers a fixed charge per customer (connection), which depends on the diameter of the connection. 

In order to estimate the variable charge, the Chilean tariff law introduced the concept of the incremental development cost, which is defined as the value that applied to the incremental forecasted demand generates the necessary revenues, so as to cover incremental operation efficient costs and the required investment associated to an optimized expansion project the WSS firm.  The incremental development cost is determined such that the net present value of the optimized expansion project is equal to zero (D.F.L. No 70/1988).

The variable tariff also considers the value of water so that consumers consider the scarcity of water in their consumption decisions[2].  This generates correct incentives to conserve water in resource scarce areas.  For example, average variable non-peak and peak tariffs in the Dry Pacific arid system are $1.3/m3 and $2.2/m3. In the Southern Humid Pacific System, on the other hand, they are $0.88/m3 and $1.3/m3, respectively. Fixed tariffs also vary according to water scarcity representing $1.9/m3 and $0.8/ m3 in the Dry and Southern Humid Pacific systems, respectively (SISS, 2013).  Additionally, evidence that tariffs send the right signals to consumers is that average monthly household consumption has significantly fallen since 1998 from approximately 25 m3/household/month to 18.6 m3/household/month in 2013 (Figure 3).

Figure 3: Average monthly household water consumption (m3/household/month) (SISS, 2013)

The affordability criteria is met by the provision of subsidies directly to the most vulnerable households. Households are classified based on an annual survey (Encuesta Casen) which estimates household per capita income.  In order to qualify for the subsidy, households must not have payment arrears with the service provider. The central government transfers the block subsidy to the municipalities; the latter use this to pay a share of each of the eligible household’s water bill; the payment share ranges from 15 to 85 per cent of the water bill, with the poorest families getting the highest share. The subsidy covers a consumption of up to 20 m3. The Social Development Ministry (Ministerio de Desarrollo Social, MDS) uses the household survey information for each Region of Chile to determine the size the block subsidy that needs to be transferred to the municipalities. The WSS providers bill the benefiting households for the net of subsidy amount, but indicating the full consumption cost, and then charge the municipality for the subsidies granted[3]. The municipality will be charged interest for late payment, and the WSS provider can discontinue service to benefiting households if there is non-payment by the municipality. In 2011, 15% of WSS provider customers were benefited (6% of total sales), at a cost of $80 million, and an average monthly subsidy per household of $10.

In order to obtain the necessary investment funds to improve its performance the WSS sector’s indicators, during the period 1989-99, an institutional model was put in place where the regulatory and supervisory functions were separated from the investment, production and sale of service functions.  The new regulatory regime, which considered concessions to establish build and operate water and sanitation services by private providers, led to an increase in private participation in the provision of WSS services from 5% in 1999 to 95.5% in 2013.  This process also led to a significant increase in average annual investments from $200 million to $500 million in 1999 and 2013, respectively (Figure 2).  This is mainly due to the increased rate of return on capital, due to increases in tariff rates. Tariff rates are determined so that investors receive a low-risk return of at least 7% on capital expenditures and therefore private WSS providers have the incentive to invest in water provision, wastewater collection and treatment (Hearne and Donoso, 2005). For example, sewage treatment coverage increased from 17% in 1999 to 99.8% in 2013 (Figure 2).

This reform period coincided with the era of high economic growth (6.2% per year) with real incomes rising significantly. Williams and Carriger (2006) propose that the transformation of the WSS sector would not have been so successful without these high rates of growth. The level of investment needed to attain this coverage could not have been reached if the Chilean Government were responsible for investment. With tariffs set centrally for water and sanitation, efficiency incentives exist for the companies to increase returns on investment. This has happened and these companies perform well on the Chilean Stock exchange (Bitran and Arellano, 2005).

Currently there are 53 water and sanitation service providers operating in the urban areas of Chile. They function as private companies although the state investment company, ECONSSA, still owns a considerable number of share in most companies (Hearne and Donoso, 2005). Five of Chile's 13 regional water companies were fully privatized with partial sale to multinationals in 1998.

The WSS providers service more than 4.5 million clients[4], 94.4% of clients are domestic, 4.7% commercial, 0.2% industrial and 0.7% other. Additionally, 95% of all clients have both drinking water and wastewater connections. The other 5% have either one or the other, with most having only drinking water connections.
The large and medium service providers (8 of the 53) serve 84.2% of all clients. It is interesting to note that a municipality (SRMPA of the Maipu municipality) owns one of them. Private providers service 95.5% of all clients.

With respect to the service quality, Figure 4 shows that costumer’s satisfaction levels since 2008 are over 99%. WSS clients were quite satisfied with the service, rating it with a 5.3 on a scale of 1 to 7 (GWI, 2013). 

Figure 5: Water service quality (SISS, 2013)

Therefore, the new regulatory scheme in the Chilean WSS sector has provided the right economic signals for an efficient allocation of resources. It has also led to meeting the set goals for service coverage.  Additionally, the transformation of the WSS sector has led to the
a)      Improvement in quality of service
b)      Increase in WSS provision coverage, despite rapidly increasing urban populations; and
c)      Increase in water conservation by customers.

In summary, Chile’s policy of providing water supply and sanitation (WSS) services through privatized regional and local water companies has been a notable success.


  1 Bitran, G. and P. Arellano, 2005, Regulating Water Services, Sending the Right Signals to Utilities in Chile, Public Policy for the Private Sector, World Bank, Note number 286, March.2005. Available at Background Document

  2 Chavez, C. 2002, Public-Private Partnership And Tariff Setting: The Case Of Chile, OECD Global Forum on Sustainable Development Conference on Financing the Environmental Dimension of Sustainable Development, 24-26th April, OECD, Paris,

  3 D.F.L. No 70/1988, 

     4   Executive Decree 453 of the 1988 Law N° 70, of the Ministry of Public Works,

   5 GWI, 2013, Global Water Intelligence Market Insight: Chile. Media Analytics Ltda. UK.

     6    Hearne, R. and G. Donoso, 2005, Water Institutional Reforms in Chile, Water Policy, 7 (2005), 53-69.

   7  SISS, 2013, Informe de Gestión 2013.

   8 Williams, S. and S Carriger, 2006, Water and Sustainable development: Lessons from Chile, Global Water Partnership, Policy Brief 2, Technical Committee (TEC). Available at

   9 WRI (World Resources Institute). 2003. Earth Trends Country Profiles. (

[1] Long-term infrastructure investment costs are included in the water and sanitation services tariff rates.
[2] The value of water for each WSS provider is determined by market prices of traded WUR.
[3] This practice does not distort the price signals. 
[4] A client is determined by the property, rather than the individual, that receives services and is billed for these (more than one person may live in the same property, benefiting from the services).