Three mornings a week, Rafael Sanabria rides his Russian-made bicycle 1 mile to a church located in the center of this city about two hours east of Havana.

The 73-year-old retired bus driver doesn’t come for the prayer or even the yoga class offered in the community hall at the Presbyterian church known as “El Fuerte.”

“I come for the water,” said Sanabria, after he parked his bike and pulled two empty 1-gallon bottles from a burlap bag.

“It’s safer. We use it for drinking. There are six people in my household. We used to drink the tap water, but there were problems with cholera and diarrhea.”

Sanabria, and about 100 others who came to El Fuerte during the two hours it was available on Wednesday morning, enjoyed the free and safe drinking water thanks to members of St. Charles Avenue Presbyterian Church in New Orleans.

Over the past 15 years, dozens of church members have either donated money or gone to Cuba to assist El Fuerte, which takes its name from an old Spanish fort a block away. In Cárdenas, it is known as “the water church.”

Ten church members came from New Orleans in May 2012 to install a water purification system.

Church officials in Cárdenas credit the system with reducing water-caused sicknesses in the community. The free water also means a lot in a country where the average wage is about $20 per month. Each bottle of water would cost $1.90.

Church officials in Cárdenas affectionately refer to the New Orleanians as the “St. Charlies.”

“We consider them to be family,” said Yamilka Gonzalez, El Fuerte’s pastor.

Members of the New Orleans church also have installed a clean water system at the other Presbyterian church in Cárdenas, known as Juan G. Hall.

“It’s a blessing of God to have this water,” said Rosa Rozada, who manages El Fuerte’s water system.

Officials at the New Orleans church said political differences between communist Cuba and the United States have not been a barrier.

The relationship with El Fuerte began in 1999 after Nell Johnston in New Orleans raised the money to replace a roof lost to neglect. Dr. Paul DeCamp planted a palm tree that now towers over the church.

In 2011, about a dozen members of the St. Charles Avenue church came to El Fuerte to test whether the government-provided tap water was contaminated. They used materials provided by Living Waters for the World, a program created by a Presbyterian pastor named Wil Howie that had established clean water systems throughout the world.

“The water turned black,” said Laura St. Clair, who has led several trips to Cárdenas. She and the others from New Orleans decided then and there that they had to install a Living Waters system at El Fuerte. “I’ve never seen a group of people so galvanized.”

Back in New Orleans, a private donor gave the $7,500 needed to buy the Living Waters system, which included PVC tubes, pumps, filters and the like. Others preassembled the equipment in the New Orleans garage of church member Wes Alden.

The 10 who went to Cuba traveled under a special religious license granted by the U.S. Treasury Department. Once in Cárdenas, several of them were tasked with explaining the benefits of the water system, while others installed it.

On the day it opened, “there were smiles, hugs, tears and praising the Lord for the community of believers,” Ann Van Horn said. “It makes me feel very blessed and humble.”

Gary Elkins, a tax attorney from New Orleans, was one of the 10 who installed the original system. He and his wife, Kate, returned to the church last week with 80 pounds of spare parts. While church officials examined the bounty, Elkins explained how the system worked.

“This is the ultraviolet filter that sanitizes the water,” he said. “The water flows through it, and the light kills the bacteria. ... These are the microfilters for the amoebas and protozoa.”

Once the regular tap water has circulated through the filters and ultraviolet light, it is stored in two 350-gallon tanks on the roof. That is enough to supply water for about two hours on the three days it is available.

The benefits of the system were on full display Wednesday morning. A steady procession of residents began arriving even before the water began to flow at 8 a.m. They came on foot, by bike or even on one of the horse-drawn carriages that serve as taxis in Cárdenas.

Practically nobody owns a car in Cárdenas. Its best-known resident is Elian Gonzalez, the young boy who returned home in 2000 at the insistence of Fidel Castro after his mother died at sea carrying him to Florida, where his Miami relatives sought to keep him. Now a university engineering student, he lives with his father two blocks from El Fuerte.

All of the people who came to the church gave their empty bottles to a volunteer, who placed them under one of the three outdoor spigots connected to the water filtration system on the inside part of the wall. It took only a minute to fill each bottle.

Once his three 1-gallon bottles were filled, Fernando Mirabal carried them away.

“I’ll be back on Friday,” he said on the way out.