Project Spotlight: Mexico's Playas de Rosarito desalination plant

Friday, July 7, 2017

Due to its semi-arid climate and drought-prone location, as well as its dependence on water supply from the Colorado river, Baja California is one of the Mexican states most affected by water shortages. Hence, local and federal authorities have been keen on finding alternative water sources. 

In recent years, the northwestern state has pushed for the construction of large scale desalination projects, such as El Salitral in the city of Ensenada, which is currently being built

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A couple of years ago, authorities began plans to build a similar facility in Playas de Rosarito, in the northwestern part of the state and south of the border city of Tijuana.

Map showing the location of the desal plant and the proposed pipeline to supply other cities in the state (CREDIT: NSC Agua)

The initial idea was that the plant would supply potable water to the state's coastal areas, which currently rely on the Colorado-Tijuana aqueduct. Later, it was decided that the initiative would be developed under a public-private partnership (PPP).

The state government awarded the project to the Aguas de Rosarito consortium, comprising French firm Degrémont, a subsidiary of water solutions powerhouse Suez group, local company NSC Agua and Singapore's Nu Water in June last year. The 40-year contract to design and build the plant in three years and operate and maintain it for the remaining 37 before turning it back to the state was signed in August.

The consortium is also in charge of securing financing for the project.

NSC, a subsidiary of Cayman Islands-based Consolidated Water, had previously conducted an equipment piloting plant and water data collection program at the proposed feed water source for the initiative back in 2012 and 2013


Once completed, the facility will become the largest desalination plant in the western hemisphere. It will ensure the Tijuana-Rosarito beach region's water needs are met for the next 50 years, benefitting over 1.7mn residents of the cities of Rosarito, Tijuana and Tecate.

Through the use of reverse osmosis technology, the facility will have production capacity of 2,200 liters per second or 50mn gallons per day in the first stage.

The plant will be constructed in two phases. The first is expected to launch in late 2019 or early 2020, while the second phase would begin by 2024, doubling capacity to 4,400 liters per second. 

The water produced would then be sold to the state's water utilities, which would be in charge of distributing the resource to the population.

The construction site for the facility is set to be a 20.1ha lot in Rosarito beach, which was acquired by NSC Agua. The site is located near the Presidente Juárez thermoelectric plant – managed by federal power utility CFE – and according to NSC Agua, the water will be treated using a cooling system from the power station.

The initiative also entails the construction and operation of a 29km two-pipe aqueduct to convey water to storage tanks in Tijuana.

The project is included in the portfolio of the Border Environment Cooperation Commission (BECC), and the North American Development Bank (NADB) was reported to be helping to arrange financing with a group of banks.

Based on state government information, estimated investment for the project is 9.89bn pesos (US$542mn).

Ana Giros, Suez's Latin America CEO, told BNamericas earlier this year that the project is critical for Mexico as it would make the country less dependent on the Colorado river, and given the rapid industrialization of the region and the increase in agricultural production.

Although construction was set to start this year, works have yet to begin. 

According to Giros, as of February the companies involved and government officials were in the process of obtaining financial closure, having already established a master trust. The firms were working to form a special purpose company that will sign the build-operate-transfer contract, and all parties were expecting to close the financing by the end of the northern hemisphere summer, she said.

Roberto Olivares, executive director of the national association of water and sanitation utilities Aneas, told BNamericas last month that the plant's development was progressing slowly due to the enactment – and subsequent repeal – of a water law in Baja California earlier this year that drew large protests and created a complicated political situation.


Although state authorities have said that the plant's objective is to reduce the region's dependence on water from the Colorado river, there has been talk about sending some of the water produced at the facility across the US border to San Diego utility Otay Water District through a pipeline during the plant's second phase.

NSC has said that it was seeking contracts with proposed customers in the US for the sale of the desalinated water. In 2012, the company signed a letter of intent with the Otay Water District to deliver 20-40mn gallons of water per day from the plant. Otay is said to already have submitted an application to US authorities for a permit to build the pipeline and import the water. The project is even listed on the California utility's website.

The plans to export water to the US have created a stir in Baja California, as such a move is not currently permitted by Mexican law.

Local authorities, however, have denied claims that water from the plant will be supplied to San Diego, although they confirmed that Otay had requested water from the facility. According to the state's infrastructure minister, the facility is being built to meet local water demand until 2050, and until that date the water it produces will only be supplied to Mexico.

Map showing the precise location of the proposed desal plant (CREDIT: Otay Water District)

SIDE PICTURE: A view of Rosarito beach in Playas de Rosarito