Privatizing Neptuno Project dead in the water in Uruguay
A woman holds a sign that reads "Resistance and Organization, we are water" at the March for Water in Montevideo on March 22, 2025. Photo © Mónic Só.
Opinion • Diego Castro • October 2, 2025 • Leer en castellano
After years of protest and resistance, the Uruguayan government cancelled the Neptuno Project—a megaproject that would have privatized a large part of the drinking water available to over 60 percent of the population. Doing so was in direct conflict with the Constitution, and opened the doors for a potential environmental disaster.
The cancellation of Neptuno is the a product of a popular veto, and it constitutes one of the few positive developments for social organizations in the first months of President Yamandú Orsi's new progressive government.
The group of leading construction companies that banded together to bring Neptuno to life in 2020 is still in business with the government, and is set to carry out similar projects elsewhere. The privatizing consortium is known as Aguas de Montevideo, and its made up of companies including Saceem SA, Berkes SA, Ciemsa and Fast Limited, all of which are of mixed national and foreign capital.
Uruguay’s previous right-wing government, led by Luis Lacalle Pou, took advantage of the 2023 drinking water crisis to push a so-called solution to the issue of potable water in Montevideo and the metropolitan area.
During the crisis, more than half of the population of Uruguay experienced saltwater contamination for over two months. This was due to a combination of drought, overexploitation, and inadequate management of the Santa Lucía River.
Social organizations, territorial collectives, and committed scientists warned that the Neptuno Project was too expensive, would not guarantee water quality, and would not solve supply problems.
The proposal from the private sector was to build and run a new water treatment plant on the River Plate in Arazatí, in the department of San José. The works were to be financed by public money via fees paid over a 17 year period.
Criticism of the project centered on its cost, the involvement of private companies, and the quantity and quality of the water supplied. The Neptuno Project would have provided only 23 percent more drinking water than what’s currently available. That wasn’t enough to meet demand in the case of future crises similar to the one in 2023.
Using water from the River Plate poses serious problems in terms of purification and public health risks: it has high salinity levels for much of the year, is contaminated, and experienced frequent toxic cyanobacteria blooms.
Finally, the $300 million project would have ended up costing almost three times as much as what was budgeted. And, most concerning of all, it would have been totally unconstitutional.
Public outcry against Neptuno
In 2004, Uruguay became the first country in the world to enshrine the right to water in its Constitution. The reform prioritizes the social use of water over commercial use, and bans private companies from participating in water treatment. The state is responsible for ensuring effective compliance, and creating tools to enable users and civil society to participate in watershed management.
Despite a legal framework that protects water, most of Uruguay’s watersheds are contaminated, due in large part to the impact of industrial activities. There is a strong tradition of organizing in defense of water in Uruguay, a tradition which is activated in the face of every threat. Well established organizations intervene, and more recently, local and national groups have emerged in defense of water and life.
A group of elders walks in the March for Water in Montevideo on March 22, 2025. Photo © Mónic Só.
Resistance to Neptuno involved a wide range of initiatives at different levels: local resistance, broad mobilizations, legal action (arguing unconstitutionality and invalidity), as well as critical contributions from committed scientists. Together, this organizing led to a profound shift in awareness of the issue.
The organizations, neighborhood groups, and rural producers in Arazatí, in the Department of San José began to mobilize in 2020 as the first rumors about Neptuno began to circulate.
From there, stakeholders were moved to action by the risk of contamination of the Raigón aquifer, the impact on tourism and fishing activities along the coast, and the potential for the flooding of rich, productive land—mainly used for growing potatoes—to create a reservoir.
Protests, open discussions, and workshops with scientists were held locally, and public information requests and meetings with local and national politicians were organized, among other activities.
Since the existence of the Neptuno Project became known in 2020, the national organizational network linked to water has denounced and opposed it. Their rejection was expressed in the annual marches for water, during the self-organized saltwater mobilizations of 2023, and during a sit-in organized by the Water Coordinator and the Tucu Tucu group in Arazatí in October of that year.
There was also a walk from the coastal region of Arazatí to Montevideo in June of this year, and a tent set up in front of the presidential palace by Ningún Neptuno (No Neptuno), from March to June. A key thread of this and other organizing was the insistence on restoring the Santa Lucía watershed, instead of letting it fester as a sacrifice zone.
Challenges on all fronts
The legal challenge arguing the “unconstitutionality” and “absolute invalidity” of Neptuno was another important element. The legal complaint against the contract was filed by social organizations, led by the National Commission in Defense of Water and Life and the Tucu Tucu de Arazatí group, supported by lawyers from the University of the Republic.
Their main argument highlighted that by allowing private entities to participate in water purification and failing to comply with the principle of public participation, the project violates Article 47 of the Constitution, as established in the 2004 reform.
In June 2023, a judge upheld the case, and in December, it was ratified by the Court of Auditors. Later, other judicial entities subsequently dismissed the case, but in the interim the government was prevented from moving forward with the contract, and construction was stopped for several months.
Environmental movements in Uruguay, particularly those related to water, have consistently sought the support of committed scientists. The struggle against the Neptuno Project was no exception, replying as it did on numerous contributions and initiatives from scientists.
In December 2023, the Limnological Society of Uruguay issued a statement of environmental concerns about the project.
In March 2024, several scientific groups criticized the government's stance preventing courts from receiving testimony from “prominent specialists,” by claiming scientists were not impartial. In December 2024, over 25 scientists from various disciplines delivered a letter to President-elect Orsi, pointing out that the project was without basis.
A protestor bangs a drum during the March for Water in Montevideo on March 22, 2025. Photo © Mónic Só.
The resistance against the Neptuno Project brought together Uruguay’s historic triple alliance—that of public sector workers' unions, social and territorial organizations, and scientific groups—all of which participated in struggles for water in the lead up to the 2004 constitutional referendum.
This time around the movement was nourished, strengthened, and renewed with energy from the feminist and anti-extractivist struggles, as well as the efforts to put life at the center of our politics.
There is a growing awareness of the need to reconnect with water and the fabric of life and to set limits on the ideology of development and economic growth at all costs. This was embodied by dozens of collectives and groups that took action against Neptuno.
A cautious celebration
The cancellation of the Neptuno Project reflects the power of public protest and the pressure we can exert. This calls for celebration.
But this victory doesn’t mean we don’t face other problems. The initiative, which clearly crossed a line, was the product of corporate greed driven by a group of construction companies that must continually expand their activities to maintain profits.
This is the same group of companies that previously built a railway for the Finnish paper mill UPM, one of the world's largest. The same consortium has carried out a string of extractive mega-projects, funded primarily by public funds and subsidies, that boost the gross domestic product while under construction. These projects constitute an important part of the economic growth trap, in which “jobs” are used in order to manipulate public opinion.
Meanwhile, the progressivise Frente Amplio government that called off the project seems unwilling to take any more business away from this consortium. They continue to negotiate in secret, despite being constitutionally required to ensure watershed management is conducted with citizen participation.
This should come as no surprise. Once in power, progressives are just as committed to keeping the wheels of economic growth turning as the business community and the right wing.
The newly proposed alternative to Neptuno doesn’t stop the destruction of the Santa Lucía River, Montevideo's primary source of drinking water. Nor does it address the main issue with the capital's drinking water supply: leakage due to faulty pipes and underground networks, which account for over half of all drinking water being wasted.
There are also plans to dam the Santa Lucía basin, which will have a major environmental impact, flooding native forests and resulting in biodiversity loss. If built, this dam would not comply with the “golden rule” for supplying large cities: having two different sources, each capable of producing 70 percent of total demand for drinking water.
As we celebrate our victory over the Neptuno Project, we’ll remain vigilant around what decisions are made in coming months. The latest news regarding the national budget and the new push for agricultural irrigation points to a continuation of extractive policies and the appeal of capitalist maximization for the new government. Its mantra seems to be that everything can be sacrificed, so long as the economy grows.
We must keep our eyes and ears open, and trust in our creativity, our mobilizing power, and the vital political sensibilities that kept Neptuno out.
