Nahir Curbelo is not part of Uruguay’s champion national rowing team, but she certainly knows how to handle a canoe and oars.

For the past two years, Ms. Curbelo has been part of Rowing Against the Current, a regional initiative started by Catholic groups to draw attention to the worsening state of water resources in Latin America.

In Uruguay, Ms. Curbelo and around 40 other activists rowed for 30 miles along the Santa Lucía River last March. The Santa Lucía, running about 150 miles, is not the country’s longest or largest river, but it is the source of drinking water for more than half of Uruguay’s 3.4 million people, including residents of the capital, Montevideo, and it is under increasing pressure from contamination and overuse.

“Our goal of rowing along the Santa Lucía is to raise awareness to the threats suffered by the river and territory,” Ms. Curbelo said. “On the river, you feel the current and hear the sounds of the water. You enjoy the beauty but also see how it is suffering from the consequences of human activities.”

“The water we drink, the water we bathe with, all of it comes from this river, and we do not have policies to defend it.”

Rowing Against the Current began in Argentina to oppose the possible private management of the Paraná River. The group’s name comes from a successful protest in 1996 when two fishermen took to the river for a 22-day canoe journey to raise awareness of a dam project that threatened to destroy local fisheries.

Martha Arriola, a member of the Episcopal Conference of Argentina’s Justice and Peace Commission, launched the rowing movement to stop the river concession. She said it spread to Uruguay and other countries because of threats to their water resources.

Several bishops in Argentina support the rowing effort. Ms. Curbelo hopes to receive the same public support from Uruguay’s bishops.

“We are focused on themes that interest the general public and the common good. These are not always considered ecclesial issues, but it would be nice if we could have an impact on the local hierarchy,” she said.

Like many others in Uruguay, Ms. Curbelo hopes that environmental causes could get a boost when Pope Leo XIV visits later this year. “Pope Leo has continued the teaching of Francis, which is positive for the church and our common home,” she said.

Ms. Curbelo rowed on behalf of the EcoFranciscanas, an environmental group of the Missionary Franciscan Sisters of the Incarnate Word. The EcoFranciscanas are part of a broader movement of Catholic groups in Uruguay and the surrounding region organized to defend the environment, living by the message Pope Francis offered in his encyclical “Laudato Si’,” released in 2015.

These groups lobby governments, corporations and civil society to bring about changes in everything from agriculture to water use. In Uruguay, they also navigate between the church hierarchy and secular environmental groups leery of the institutional church.

Father Jorge Osorio, a diocesan priest in northeastern Uruguay, said that while the Uruguayan Episcopal Conference embraced “Laudato Si’,” it has not followed up with practical efforts on environmental concerns.

But other actors in the local church, through Caritas Uruguay, were instrumental in organizing “environmental hubs,” community-based groups focused on environmental stewardship and education. The first hubs were organized in 2016, shortly after the release of “Laudato Si’,” and now involve numerous civil society organizations.

“The bishops’ conference is not an obstacle, but there is really no focus on the environment in its pastoral work. It is a marginal issue for them,” said Father Osorio, who is active in environmental campaigns in Cerro Largo, the department where his parish is located. Officials from the Uruguay episcopal conference did not respond to requests for comment.

A new issue in Father Osorio’s part of the country is the possibility of reopening a trade corridor on Merín Lagoon along the Uruguay-Brazil border, the second-largest lake in South America.

“Use of Merín to transport goods is not new, but this plan is more extensive and will use large ships that will affect biodiversity and the lake itself. It is a short-term benefit with a lasting impact,” Father Osorio warned.

Sister Macarena Alvariza, a founder of the EcoFranciscanas, said her group has had to overcome unfounded concerns about the church from environmental advocacy organizations and political parties that are active on ecological matters.

Uruguay is the least religious and least Catholic country in Latin America, according to the Chile-based Latinobarómetro, which conducts regional surveys. In its 2024 survey, 52 percent of Uruguayans said they professed no religion—the highest in Latin America—and only 33 percent—the lowest—identified as Catholic.

“The Catholic Church here, historically, has had a much lower profile than in other countries in South America,” Sister Alvariza said. “We are a strongly secular country, and that sometimes leads to misunderstandings about our role and participation.”

Uruguay embraced its secular tradition in 1919 with the adoption of a new constitution that mandated strict separation of church and state. “When we first started participating, other groups asked if we planned to carry a statue of the Virgin Mary or try to convert people,” Sister Alvariza remembered. “They did not get where we were coming from, but these ideas have changed,” she added.

Regarding the Santa Lucía river, she said the government needs to address contamination caused by agrochemicals, wastewater discharge and solid waste, as well as understand the impact of climate change. The last major drought in 2024 had a severe effect, leading to a water crisis in Montevideo and other cities.

The EcoFranciscanas are involved in several local campaigns, working with other groups to change state policy on the expansion of tree farms that feed the country’s paper mills and the possibility of offshore oil and gas drilling. The group opposes both.

They are also part of international eco-campaigns, including Rowing Against the Current, and advocate for the proper use of the Guarani Aquifer, the world’s second-largest aquifer. It covers 460,000 square miles under Argentina, Brazil, Paraguay and Uruguay.

Lucien Chauvin contributes from Lima, Peru.