Water Resilience for Santiago de Chile
by Cristian Schwerter and Ivan Yarur Sairafi (Veolia)
This case study is drawn from the larger report Managing Water for Economic Resilience: De-risking Is Not Enough, published April 2024.
Key Messages
Chile's economic resilience is facing a critical challenge from water scarcity, which has been intensified by growing vulnerability to drought. Water demand has surged due to a period of robust economic growth and the country's heavy reliance on water-intensive industries. The mining sector alone was expected to increase its demand for water by 45 percent in 2020.
Social resilience is also threatened by droughts. In 2021, the fourth driest year in Chile, more than 50 percent of the population, or 19 million people, resided in an area that was severely affected by water scarcity.
An expected increase of 3 °C in temperature due to climate change is predicted to cause several impacts, including droughts, turbidity events, and reduced water availability from glaciers.
Government reforms implemented in 1990 have allowed private operators to enter the market and facilitated financing of over US$ 2 billion for investments in wastewater treatment plants. Currently, the Chilean water production and reuse market is fully privatized.
Privatization has enhanced the market’s competitiveness, overall water quality, and contributed to cost reduction as well as continuity to the point where the country now has 100 percent coverage in both drinking water and sanitation. For example, Aguas Andinas is the largest water and sewage utility in Chile that serves around 40 percent of the Chilean population.
Chile has achieved 100 percent treatment of its urban wastewater, which is an important step towards sustainability. However, there is an opportunity to further enhance economic resilience by transforming wastewater into a productive resource which is currently not utilized.
The private sector's role in promoting water resilience goes beyond providing water-related services. It includes assuming responsibility and leadership for responsible investment that prioritizes sustainability and environmental protection. Also, improving the efficiency of water resources and communicating responsible use protocols to their consumers.
The Climate Change Challenge
Chile, a South American nation, has emerged as one of the most prosperous in the region. Its economic strength and solid institutions have successfully weathered three major shocks: namely social unrest in 2019, the COVID-19 pandemic beginning in 2020, and the 2022 Russian-Ukrainian war. In spite of these shocks, its economy actually experienced growth by 11.7% in 2022. According to the World Bank (2021), Chile has one of the swiftest recoveries worldwide despite the remarkable contractions it witnessed — particularly following the social unrest.
Nevertheless, the Chilean economy remains challenged by high inflation (4 percent), widespread inequalities, population growth, informal employment affecting one-third of the workforce, and environmental challenges. The Chilean Ministry of the Environment states that the country is highly vulnerable to climate change. Its effects are already being felt in the national territory. Climate projections for Chile show that the main effects are a rise in temperature and a decrease in precipitation. Thus, an increase in the frequency of extreme events such as droughts and river and coastal floods is highly likely.
Chile is ranked as the 10th most water-risk-prone country out of 142 countries (4th among OECD nations, trailing only the US, Mexico, and Australia) (OECD, 2017). The northern part of the country is arid and semi-arid and is projected to see its temperatures increase in the next century, while experiencing more frequent warm storms that produce mudslides and episodes of high turbidity in the basin of the rivers. This will have negative impacts on its main productive activity: mining. The most affected area of the country will probably be the central zone, where the capital city Santiago is located. In the coming decades, precipitation reductions of around 20 percent and temperature increases of 3 °C are expected in this area. This will have important effects on the most densely populated area of the country — an area that also includes a dense concentration of its agriculture, , and hydroelectric power. Some of the effects in drinking water production are described below:
Drought: Central Chile is suffering two decades of drought. As a result, freshwater sources have experienced a continuous decline. At present, the Metropolitan Region has a worrisome structural water deficit (gap between available water resources and the real needs of the area) of up to 250 cubic hectometers under dry years hydrological conditions. This is a situation that will continue over time and could even worsen. For this reason, it is fundamental to increase efficiency in the use of water resources and adding more water resources to the productive matrix.
Turbidity events: Increased turbidity in the upper basin of the rivers has a significant impact on drinking water production and has a high probability of affecting customer supply. Turbidity events are classified into four groups: 1) winter rainfall events, 2) summer rainfall events, 3) snowmelt, and 4) extreme rainfall events (atmospheric rivers). The snowmelt event in particular is associated with the increase in temperature without the occurrence of precipitation that causes increased river flow, which in turn causes increased sedimentation.
Reduction in the availability of water from glaciers: Glaciers undergo changes in response to variations in other components such as climate, volcanic activity, and human action. These modifications are mainly evident in their geometry, volume, thickness, mass balance, and their contribution of liquid water to the ecosystem. Due to the more severe effects of climate change and the prolongation of the drought affecting the central zone, glaciers in the Metropolitan Region are losing volume at an accelerated rate, among other alarming changes. In central Chile, 65.4% of the glacier surface is located below 4,000 m above sea level. When the temperature in the valley reaches 30 °C, at that altitude there is a positive temperature of about 10 °C shortly after midday — enough to melt several meters of ice at the end of a warm summer. But glaciers are not only melting faster due to warming; they are also losing more ice by sublimation due to increasingly dry conditions, and the higher elevations fail to recharge with sufficient snow during the winter. Initially, as it melts at a faster rate, a glacier contributes more water to the basin, but only until it reaches a critical point: when it begins to decrease its water yield due to its smaller size. This puts the water supply for the city of Santiago at risk, especially in summers of dry years, when 70 percent might come from glaciers.
The Threat of Water Supply to Chile’s Economic and Social Resilience amidst Climate Change Challenges
Chile's economic resilience is facing a critical challenge from water scarcity, which is being intensified by growing vulnerability to drought. In the past few decades, Chile has experienced a surge in water demand, largely due to a period of robust economic growth and the country's heavy reliance on water-intensive industries such as mining, agriculture, forestry, and fish farming. For instance, Chilean Copper Corporation reported that the mining sector alone is expected to increase its demand for water by 45 percent in 2020, while forecasts indicate that agriculture will require an additional 4 km3 over the next 40 years (COCHILCO, 2009).
Water challenges have direct or indirect repercussions on most of the country's productive activities. In 2020, the reduction in copper production was primarily caused by supply-side issues such as water restrictions. This has diminished Chile's exports.
Social resilience is also threatened by droughts. For example, 2021 was the fourth driest year in Chilean history. More than 50 percent of the population, or 19 million people, resided in an area that was severely affected by water scarcity. In fact, according to the study “De Estructuras a Servicios” sponsored by the Inter-American Development Bank (IDB), Chile is the country with the highest proportion of its population living in basins with water stress and will continue to be in the next decades.
Certainly, Chile's economic and social resilience relies significantly on fulfilling the water requirements of its water-intensive industries and residents.
Private Sector as a Key Enabler in the Chilean Water Production and Reuse Market
During the 1980s, Chile underwent a range of free-market economic changes, one of which was the transfer of control over the country's water and sanitation services from the government to private corporations. This means that it is now the responsibility of private entities to deliver these vital services to the public.
Privatization has been very beneficial to the water sector in Chile. One of the benefits of privatization is that it can lead to increased efficiency and investment in the sector. Private companies have the incentive to provide high-quality services to customers to remain competitive and profitable. This can result in improved infrastructure, better water quality, and more reliable service for consumers. According to the regulator´s 2021 annual report, 96 percent of the Chilean customers were served by companies operated by international private groups, with SMAPA the only relevant state-owned company operating in urban areas.
Full Treatment of Wastewater
Wastewater rates in Chile in the 1990s were on the order of 20 percent. At that time, the government’s plan to improve wastewater treatment rates included reforms that allowed the entry of private operators starting in 1998 and helped finance more than US$ 2 billion in investments in wastewater treatment plants that allowed 100 percent of urban wastewater to be treated in the concession areas of private operators. Given climate change, proper treatment is only the first step in developing a sustainable approach to transforming wastewater into an economic resource. Although Chile currently treats 100 percent of its wastewater, it is only used in a low rate for productivety activities. In fact, most of the treated wastewater ends up in the sea. The environmental and economic potential of changing this is enormous: the total volume of unused wastewater could cover almost 10 percent of the country’s total hydrological deficit.
Water Continuity and Improved Water Quality
The country currently has 100 percent coverage in both drinking water and sanitation (urban concession areas). What’s more, Chile is one of just two countries in Latin America where the U.S. Centers for Disease Control recommends tap water to be safe to drink. According to a World Bank survey, in spite of the high water stress of the country, just 1.8 percent of the water companies report water supply shortfalls — one of lowest rates among surveyed countries. Additionally, and consistent with the survey mentioned, according to the Chilean Water National Regulator (SISS) the urban areas of the country have a level of continuity of the service of 99.7 percent.
Reduced Costs of Water and Sewage Services
One of the most prestigious and up-to-date sources of tariffs worldwide is the Global Water Tariff Survey prepared by Global Water Intelligence (GWI). According to that study, the average global water tariff is 2.34 USD/m3. The water tariff is composed of fixed and variable charges for drinking water, wastewater, and rainwater collection. Summarizing the GWI data by adding the fixed, variable and tax costs, we conclude that worldwide costs for potable water, sewage collection and treatment, and rainwater collection including taxes are as follows:
Drinking water: 1.27 USD/m3
Wastewater: 0.95 USD/m3
Storm water: 0.11 USD/m3
In turn, the regional composition of tariffs is as follows. In Latin America and the Caribbean, the average tariff is 1.85 USD/m3. Only the cost of potable water in Latin America and the Caribbean reaches 1.47 USD/m3. Sewage charges are only 0.38 USD/m3, probably due to the low level of sewerage (and even less sewage treatment) in most Latin American countries. The cost in Santiago de Chile is 1.23 USD/m3 (drinking water is 0.59 USD/m3 and wastewater is 0.65 USD/m3). The cost in Santiago de Chile represents 1.4% of the basket of products of the average household.
The success of the wastewater treatment plan is due to several measures:
New emission standards that began to regulate pollutants associated with the discharge of liquid industrial waste into sewage systems and the discharges of liquid waste into marine and inland surface waters
Strengthening the supervisory powers of the Superintendencia de Servicios Sanitarios (SISS) in 1998
A new regulatory framework that allowed private capital in the sector's companies.
The government's efforts resulted in benefits not only in public health, quality of life, and environmental protection, but also in economic benefits. Specifically, the decrease in wastewater irrigation has increased the potential of the tourism industry and the export potential of agricultural products. From 2000–2017, private companies invested US $2.3 billion in wastewater treatment, allowing Chile to reach treatment levels comparable to the most advanced countries in the world.
Aguas Andinas Sewage Treatment Facilities
Aguas Andinas is the largest water and sewage utility in Chile. It provides services to around 40% of the Chilean population. Its service areas are in the Santiago Metropolitan Region, where there is 100% coverage in drinking or potable water and 100% sewage collection and treatment. It is a subsidiary of Veolia Group.
In 1999, only 3% of Santiago's sewage was treated; the rest was discharged into rivers together with industrial liquid waste. In turn, the Mapocho and Maipo Rivers were persistent sources of disease and unhealthy conditions in the capital. In 2003, with the inauguration of the La Farfana Treatment Plant, this scenario began to change. Then the Mapocho-Trebal Complex was added, and in just 13 years the city was able to treat 100% of its sewage. Thanks to investments of more than US$ 1.2 billion, enteric diseases such as cholera and hepatitis were eradicated, urban spaces were recovered, and riverbanks were repopulated with wild species.
This is the great contribution of the water and sewage industry to the Metropolitan Region. As part of this process, between 2007 and 2010 the company executed the "Mapocho Urbano Limpio" project, a US$ 113 million engineering program that, as of 2011, made it possible to definitively close the 21 sewage discharges that previously fed into the urban channel of this river. It consisted of the construction of a subway interceptor collector of up to 3 m in diameter and 29 km in length, which runs parallel to the riverbed.
The process of decontaminating wastewater to make it fit to be returned to natural watercourses or used for irrigation, in accordance with the standards required by law, is carried out in two biofactories (former sewage treatment plants where residues have been transformed into products): the Trebal-Mapocho Complex (228 million m3 in 2021) and the La Farfana Plant (247 million m3 in 2021), and in twelve plants located in different localities around Santiago (34 million m3 in 2021).
The application of a model based on the circular economy makes it possible to recover the sanitary waste resulting from the purification process carried out in biofactories. Organic waste separated from water during the purification process is used in agriculture and in the regeneration of degraded soils, either directly as biosolids or after processing at the El Rutal Plant, where it is transformed into a dry fertilizer. Some 30,000 hectares benefit from these biofertilizers. This area is likely to multiply in the coming years. The biosolids go through three drying processes at El Rutal: solar, chemical, and resting. The final product has better agronomic properties than wet biosolids due to a higher availability of nutrients thanks to the mineralization generated by the biological process of biosolids. Until December 2021, biosolids from El Rutal were still considered waste and, although they could be used for agricultural purposes, they had to comply with the protocols of the National Waste Declaration System. This will no longer be necessary; in January 2022, the Agriculture and Livestock Service (SAG) certified them as fertilizers. This will speed up their commercialization. In the past year, the first sales of the product were made in this quality and agreements are expected to be signed soon. It is a product with a high nitrogen, potassium, and phosphorus content, as well as a high organic levels, high stability, and very good granulometry, which makes it easier for the plants to absorb the nutrients.
Another by-product of wastewater treatment is biogas, a fuel composed of methane and carbon dioxide, which is generated by the biodegradation reactions of biodegradable organic matter. It is currently used to heat boilers at the plants and to produce energy for self-supply, providing electricity consumed by the Mapocho-Trebal Biofactory. In addition, a sufficient volume is injected into the Metrogas (gas supplier utility) network to supply around 40,000 households in Santiago.
Private Sector’s Role in Promoting Water Resilience
In the Santiago Metropolitan Region, the most evident effects of the climate crisis are associated with a drought that has lasted more than a decade and an increase in heavy summer rains in the Andes Mountains. The following section will shed light on the role of Veolia, a private sector company, in terms of facing climate change challenges.
Turbidity Events
One effect of climate change is the increase in intense summer rains of short duration in the Andes, which cause displacement of materials that, when falling in the flows, cause high turbidity in the Maipo and Mapocho Rivers, affecting the production of potable water in Aguas Andinas Plants. In order to reduce the main associated risk (the supply cut), the company is investing in major infrastructure works with a goal to increase the autonomy of potable water supply to 48 hours. To this end, the company has invested in new reservoirs, pipelines, and wells. This has resulted in an increase in autonomy from four to 34 hours in a period of seven years. One relevant project was the inauguration of six mega-tanks at Pirque in November 2020, with a capacity of 1.5 billion liters of reserve water. These works made it possible to face the last major turbidity episode, which occurred in January 2021, without supply cuts.
New wells to produce drinking water were also inaugurated. Completed in 18 months, the works consisted of 14 wells with a depth of 300 m, a 20,000 m3 drinking water tank, and a lifting plant. This investment of US $33 million will provide an extra 1,500 L/s for the supply of more than 400,000 inhabitants of the southern area of Santiago, as well as increasing from 34 to 37 hours of autonomy in the production of drinking water in the event of extreme turbidity in the Maipo River. The wells operate remotely and are automated to guarantee a safer service and stable pressure.
In turn, the El Manzano-Independent Intake project will further complement water autonomy for the region, operating during instances of extreme turbidity events. It will help secure water without sediment for the production of potable water, tapping into the El Manzano sector 5.7 km upstream of the current Maipo independent intake and providing a flow of 16 m³/s to the Las Vizcachas production plant. In addition, it will allow filling the Pirque Mega Ponds, adding another 6 m³/s available for the production of potable water at the La Florida and Padre Hurtado Plants. The project is currently in the environmental approval process with its design and engineering stage finished.
Droughts
Central Chile has suffered more than two decades of uninterrupted drought. As a result, freshwater sources have suffered a continuous decline. At present, the Metropolitan Region has a worrisome structural water deficit (gap between available water resources and the real needs of the area) of up to 250 cubic hectometers under hydrological conditions of dry years. This is a limiting situation that will continue over time and could even worsen. Veolia has studied future scenarios, including demand and the behavior of water sources, and its conclusions anticipate a worsening. Given this scenario, Aguas Andinas has defined a range of actions aimed at reducing the water deficit by 2026 through three ways:
Increase efficiency in the use of water resources: Through its practice of measuring water use throughout the value chain, the company has been able to outline concrete actions to increase water efficiency which reduces the volume of raw water needed to meet the same demand. These actions have concentrated on three priority areas:
Optimization of raw water intake: The actions taken by the company to optimize surface water catchment, such as improving water intake and the replacement of gates between the instake and the plant, have allowed this activity to be near its maximum level of efficiency. On the other hand, measures are also being applied to implement state-of-the-art water management of the company’s 250 extraction wells. Following a successful pilot plan in 2020 and a corresponding tender in 2021, in January in 2021, a four-year project was initiated with the goal to digitize the wells alongside a more efficient management methodology that will allow for more water, less energy consumption, and better control of the associated risks.
Greater efficiency in drinking water production plants: The advances in operational management issues carried out in 2021 allowed the company to continue advancing in its water efficiency strategy during the following year, achieving new reductions in the levels of losses of the drinking water production plants. The statistics for the year indicate progress. In 2022, 200 L/s of raw water were recovered, reaching a loss margin of 4.8%, a figure 0.9% lower than in the previous period.
Greater efficiency in detecting and repairing leaks: Around 30% of the drinking water produced by the company ends up as unaccounted for or unbilled water. To address this, the company has a Water Efficiency Plan that is a set of initiatives that seek to speed up the detection of leaks and their repair — tasks that require enormous efforts given the extension of more than 13,000 km of underground network that feeds homes in the capital. In 2021, it was concluded that annually the company was able to detect and repair a number of leaks similar to those produced by the natural deterioration of the network. To break this cycle, in 2022 a project was started to double the detection and repair capacity through new technologies and methods. In the 12 months of its implementation, the recovered water for leaks found and repaired grew from 200 to 500 L/s.
Adding more water resources to the company's matrix: Since there is a limit to the efficient use of resources, there comes a point when it is necessary to look for other alternatives. Considering this reality, the company is pushing for a series of infrastructure projects and agreements with other users in order to increase the contribution of water to its matrix.
Groundwater extraction: Over a three-year horizon, the company aims to increase the amount of potable water produced from underground sources from 15% to 30%. To this end, it has already implemented several medium-sized projects, adding around 800 L/s to its matrix. Even some sectors in the western and southern areas of Santiago, which had a mixed supply, now have a supply based exclusively on underground resources. In addition to the above, the Cerro Negro-Lo Mena wells add 1,500 L/s to water production.
Collaboration agreement with irrigators of the first section of the Maipo River: The yield of Aguas Andinas' rights on the Maipo River (27% of the total) is no longer sufficient to supply the city of Santiago. The most feasible solution to alleviate this deficit is to make more surface resources available, which was achieved thanks to an agreement signed in August 2021 with the seven irrigation associations that have rights to use the first section of the river. This agreement is historic for several reasons: for the first time the different users in this sector of the basin recognize the existence of a structural problem that requires a joint and long-term response. Usually, each year the company coordinates with the irrigators to maintain the volume of the El Yeso reservoir, which protects Santiago's water supply, at a safe level, but this new agreement guarantees the permanent availability of the water resource and provides sustainability to the basin through initiatives with an integrated approach. Its most important points include a diagnosis of the management of the first section of the river, which is in charge of a surveillance board, to ensure the maximum level of efficiency. Human consumption is prioritized over other water uses, and if the city's supply requires it, the irrigators will contribute water at a fair price. The agreement entails an obligation to make the necessary water transfers to maintain the safety levels of the El Yeso reservoir and establishes a flow curve that meets the demands of all parties involved. Aguas Andinas commits to implement projects that will make the use of the basin sustainable, including the reuse of treated sewage and the drilling of emergency wells in the irrigators' canal strips to contribute to irrigation. The development of a master plan for the basin by all parties will also consider the future evolution of demands, rainfall, and flows, with a view to ensuring its long-term sustainability.
Reuse of treated water in the bio factories: The company is studying a series of projects to apply the principles of the circular economy to the region's water supply. The most relevant involves treated water from the Mapocho-Trebal Plant and was included in the agreement with irrigators. The objective is to efficiently and optimally manage the basin, maximizing the availability of water in an equitable manner and allowing a balance in water availability. The project includes a connection from the Mapocho-Trebal Biofactory to the Irrigation Associations of the First Section of the Maipo River, who, in turn, will provide the equivalent of raw water from the river to supply the city, increasing the availability for human consumption. The project is going through the environmental evaluation, design, and engineering stage, and its materialization is scheduled for the next few years. It received a great boost when it was included in the collaboration agreement and obtained the approval of the authorities and different interest groups. It should be noted that, at present, treated flows from the biofactories are already being used for irrigation, but downstream of the biofactories.
Another initiative under study is the infiltration of treated water into the region’s underground aquifers to prevent the prolonged drought from depleting their natural recharge capacity. Although it has not yet been scheduled to begin, it is gaining increasing public consensus.Responsible use campaigns: A comprehensive solution to water scarcity also requires the involvement of end consumers. For this reason, the company carries out a series of actions to raise awareness in the community about the urgency of using water responsibly.
Every drop counts: To reach residential consumers, Aguas Andinas deploys campaigns through its digital networks and constantly reinforces its presence in the media, alerting about the drought and its consequences. On October 25, 2021, it launched a massive campaign for responsible use, which aimed to change the habits of its customers. With the slogan “Every drop counts,” companies and other economic sectors such as agriculture and every household in Greater Santiago are invited to join in the care of water.
Coordinated management with municipalities: For the last three years between November and April, in view of the large volume of water that municipalities allocate to irrigating green areas, Aguas Andinas delivers to each mayor of the region a report with the detailed consumption of public spaces so that they can check for water leaks. Since 2020 this campaign has shown a positive evolution. That year for the first time the consumption of maintenance of green areas fell, which until then showed an upward trend. This was achieved thanks to concrete measures, such as the replacement of lawns with low water consumption species in squares and the installation of digital meters to monitor irrigation in green areas.
Biociudad: Currently, Aguas Andinas presented Biociudad. It is a proposal by Aguas Andinas that consists of specific projects and solutions to add hydrologic adaptation and resilience that Santiago needs in the face of climate change. It considers a mix of initiatives with an investment amount of US$ 1 billion by 2030 (o/w c. 26 percent already executed). Biociudad responds to the active and proactive role that Aguas Andinas has led in the face of climate change, seeking to fulfill its main commitment: to provide a safe, continuous, and reliable supply, even in increasingly extreme weather conditions. This new proposal arises within a scenario in which the development of the public-private partnership has been relevant for the progress in providing drinking water, sewerage, and wastewater sanitation coverage during the last 25 years, a journey that foresees the future challenges that the country will have to face in a joint and collaborative manner at the time of decision making. Biociudad’s line of work is framed within five strategic pillars, including projects and solutions in various stages of execution.
Increasing Resilience for an Uncertain Future
Chile’s economic and social resilience relies significantly on fulfilling the water requirements of its water-intensive industries. Unfortunately, the country is facing remarkable water scarcity, which is being exacerbated by an increasing vulnerability to drought. The challenge of water scarcity is impeding the country’s productive activities. For instance, in 2020, water restrictions caused supply-side issues that led to a reduction in copper production, thereby decreasing Chile’s exports.
Droughts also threaten social resilience, and in 2021, over 50% of the population (19 million people) lived in areas severely affected by water scarcity. According to a study sponsored by the IDB, Chile is currently and will continue to be the country with the highest proportion of its population living in basins with water stress in the coming decades.
Addressing the challenges of climate change requires promoting efficiency in consumption, increasing water efficiency, promoting water reuse, generating new water sources, and preserving the quality of water sources. It is also essential to have a regulatory framework that promotes not only efficiency, but also risk mitigation, encourages investment, facilitates and accelerates the execution and financing of new works, and promotes water savings while maintaining the self-financing of the companies. Investments are needed in reuse of treated wastewater, desalination, infiltration into aquifers, reduction of water losses, lining of canals, reservoirs, wells, and nature-based solutions.
The private sector plays a crucial role in the development of innovative solutions and the implementation of sustainable practices for efficient and effective management of water resources. Within the water sector, they can contribute significantly to the implementation of adaptation policies and programs to address water-related challenges. Private sector operators possess the necessary expertise, access to cutting-edge technologies, and sustainability credentials. As a result, their involvement can facilitate the development of cost-effective solutions and help mitigate the impact of water scarcity with less costs and more efficiency.
Despite the lower availability of water in Chile, the drinking water and sewerage companies have maintained high levels of coverage, continuity of service, and quality standards. Likewise, thanks to the works executed by the private sector, problems due to floods and turbidity events have been avoided. Key attributes to successes were the Chilean regulatory framework and tariff structure that incentivized the private sector to operate in transparency. The private sector companies also assumed responsibility to drive change by not only implementing projects for water reuse and drilling wells for underground water, but also raising awareness amongst residential consumers and deploying water usage awareness campaigns through digital networks.
References
COCHILCO. 2009. “Proyección consumo de agua en la minería del cobre 2009-2020.” COCHILCO.
OECD. 2017. "The governance of water infrastructure in Chile." In Gaps and Governance Standards of Public Infrastructure in Chile: Infrastructure Governance Review. Paris: OECD Publishing.
World Bank. 2021. “GDP (current US$) - Chile.” https://data.worldbank.org/indicator/NY.GDP.MKTP.CD?locations=CL