This story has been updated.
The National Park Service has completed repairs to San Antonio’s 275-year-old Espada Aqueduct, thanks to a $290,000 federal grant from the Great American Outdoors Act.
The act, which passed in 2020, provides funding to national parks to improve infrastructure and expand recreation opportunities. No local money was spent on repairs.
The Espada Aqueduct was built between 1740 and 1745 using Native American labor. The aqueduct is part of the Espada Acequia system that served Mission Espada and nearby farms; it was built to carry water over Piedras Creek.
Often called the oldest Spanish aqueduct in the U.S., it is also the only one that still carries water. The aqueduct is a National Historic Landmark within the San Antonio Missions National Historical Park, which is also a World Heritage Site.
“We wouldn’t have a national park without these pieces,” said PT Lathrop, chief of interpretation and education for the San Antonio Missions National Historical Park. “It’s not just a ditch. It is a piece of history that helps this park remain historically intact and historically accurate.”
The work was done by craftspeople from the park service’s Historic Preservation Training Center, San Antonio Missions National Historical Park and youth from the Texas Conservation Corps.
The San Antonio Missions National Historical Park has a long-standing relationship with the Texas Conservation Corps, including apprentice programs in preservation masonry and cultural landscapes.
The project team first drained the aqueduct using a diversion gate, then cleared about 30 yards of mud and soil sediment by hand.
After the masonry channel was clear, the team repaired small cracks and weak mortar joints. Preservation treatments were then applied to the inside of the channel and on the exterior masonry.
The work was completed Friday, said Lathrop, and the aqueduct refilled, but the team discovered a leak, and so drained it once more to repair that leak.
Through its almost 300-year history, the original stone of the Espada Aqueduct has survived flash floods and other natural occurrences, leading to leaks and a build-up of sediment and debris.
Infrastructure funding from the Great American Outdoor Act and the bipartisan infrastructure law, which passed in 2021, is part of “a concerted effort to address the extensive deferred maintenance and repair backlog in national parks,” according to the park service.
The Great American Outdoor Act primarily funds major infrastructure projects, but a percentage supports regionally-based maintenance teams, which allow the park service to tackle projects, like the repairs to Espada Aqueduct, that require skilled work at a time when fewer people are practicing traditional trades.
According to the park service, the San Antonio Missions hosted more than 1.3 million visitors in 2021. Those visitors spent $104 million, which supported 1,640 jobs in the area and had a cumulative benefit to the local economy of $165 million.
“Being able to preserve our community’s heritage, character, and sense of place is invaluable in experiencing and understanding the cultural identity of our past and future,” said Christine Jacobs, park superintendent for the San Antonio Missions National Historical Park.