From Feb. 16, 1861, when Gen. David E. Twiggs surrendered federal troops in the Alamo Plaza without a shot being fired, until the end of the Civil War on April 9, 1865, San Antonio was part of the Confederacy.

There’s not much to see that recalls that chapter in city history. The Alamo ruins were used as a storage depot, the then-unfinished Arsenal – now H-E-B’s corporate headquarters – and the Confederate cemetery on the near Eastside are among the few physical manifestations of that time. A monument to Confederate soldiers stands in Travis Park. That’s about it.

Until now.

City workers excavating a perimeter waterway at the San Antonio Zoo have uncovered what appears to be a Civil War-era, limestone sluice that channeled wastewater from the Confederate Tannery into the Spanish acequia and San Antonio River. State and city historic preservation officers reviewed plans for the City’s wastewater improvement project at the Zoo, but the scope of the project changed over time. No one anticipated a significant historical find.

“It’s hard to put a shovel into the ground anywhere in San Antonio without hitting something that’s important,” said Mark Denton, the veteran archeologist with the Texas Historic Commission who oversees the San Antonio region. “It’s an emergency discovery. We wish we would have found it earlier. The historical significance? If it really is a feature associated with the tannery, then it’s interesting and unique.”

Tannery Stones at Brackenridge Park
Beyond the early 20th century, dragon-tooth stone wall on the San Antonio’s Zoo perimeter, the Confederate-era, limestone sluice channeled tannery wastewater via the existing Spanish acequia into the San Antonio River. Photo by Iris Dimmick.

Denton said the feature was uncovered more than a week ago and was originally misidentified by a local mason as an 1880-90s era sewer line. Mariah Pfeiffer, the historic preservation expert closely associated with Brackenridge Park, then saw it and realized it dated to the Confederate presence at the site. That led officials here and in Austin to halt the construction project for a closer, second look today.

UPDATE: Representatives from the City and Brackenridge Park Conservancy met with construction engineers, planners and contractors early Friday morning to discuss what comes next for the construction site and it’s surprise historical guest.

After an overview of the historical significance of the sluice and the current improvement project – to construct an ultraviolet disinfection facility to cleanse bacteria from zoo wastewater – officials came to a consensus that construction will go ahead as planned next week, but only after the sluice has been carefully removed and stored.

Pfeiffer, and others, expressed initial concern over this option.

“The number one goal (of any historical find) is to preserve in place … I’ve seen things taken apart and numbered before,” she said. “There needs to be a commitment to reconstruct (the sluice) before deconstruction.”

City officials tentatively expressed that commitment and said $1 million in funds from the 2012-2017 Bond Program earmarked for  Brackenridge Park improvements could be used to store, reconstruct, relocate and include the sluice in the park’s current interpretive signage plans.

“This definitely could be added to the list of projects already planned at (Brackenridge) Park,” said Parks and Recreation Director Xavier Urrutia. “It’s a natural fit.”

No one present at the meeting at the excavation site would venture a guess how much that work would cost.

Leaving the sluice where it is, said construction project manager Alan Thompson, would most likely exacerbate problems in an area of the park that already has significant drainage and structural problems. The current project also is intended to improve water flow in the event of a 100-year flood, a far greater degree of protection than now exists.

“Time is of the essence,” Thompson said. “We have our contractor immobilized, pumps running (which costs more) money every day … preservation is very important, but we also need to be fast.”

Brackenridge Park Conservancy Executive Director Leilah Powell, who led the discussion this morning, commented on the irony of the situation: “It’s the oldest documented point-source pollution site” and it’s in the middle of an effort to rectify point-source pollution from the zoo.

Official discussions about what to do with the sluice until a better spot can be found are set to conclude on Monday with the completion of a memorandum of understanding (MOU) between the City, Brackenridge Park Conservancy and San Antonio River Authority.

By the end of the meeting this morning, the attending stakeholders seemed confident that both the historical sluice and the modern facility have been adequately considered throughout the process so far and will continue to be in the coming weeks.

–Iris Dimmick, Managing Editor

What to Do Now is Complicated

How to handle the find poses a challenge.

“It’s a buried underground architectural feature, a sewer line, really,” Denton said. “You can’t dig it like a Roman ruin. It’s kind of like all the acequias in San Antonio. They were regularly cleaned out, so any artifacts you might find are associated with the last time they were used, maybe the 1930s. You don’t find Spanish colonial artifacts.”

The option of last resort, Denton said, is to conduct a HABS (Historic American Building Abstract Survey).

“A HABS study is done as a last measure if you can’t preserve or protect something,” Denton said, but that’s not a very satisfying outcome for historical preservationists who would like to see a rare physical manifestation of the Confederacy here protected in a way that deepens the appreciation of local history for locals and visitors.

One compromise under consideration by city and river authority officials, who will meet at the site Friday morning, is to move the feature to a ground level site nearby and add contextual signage.

“It’s our understanding that the parks and zoo people are talking about disassembling it, moving it,  and then reassembling it and using it to do interpretive education,” Denton said. “I think it would be fantastic if they can extract it and reconstruct it.”

Kay Hinds, city archeologist,  and Shannon Miller, the city’s historic preservation officer, were not immediately available for comment.

The Confederate Tannery was part of a larger plan to construct a fort on the site, but Confederate officers stationed here were never able to gang press enough slaves to carry out orders to build the fort, according to Leilah Powell, executive director of the Brackenridge Park Conservancy.

“People were off fighting the war, and there wasn’t enough labor to carry out the project,” Pfeiffer said. “As far as physical remnants of the Confederate period, I think this is it. Looking at the maps, this appears to have been appended to the existing acequia system. I think it’s pretty special.”

More of the history surrounding the establishment of the Confederate Tannery can be found here [PDF].

Nov. 23, 1863 order issued by Confederate Adjutant-General Edmund P. Turner in Houston to Major A.G. Dickinson, the commanding officer in San Antonio, called for construction of a fort large enough to house 1,000 troops with multiple cannon emplacements, sufficient to guard the “Confederate Army Tannery in San Antonio.” Texas, which was removed from much of the war’s worst fighting, was an important source of cotton, cattle, and access to export shipping routes to Europe via Mexico for the Confederacy.

A period plan for the Confederate Tannery and wastewater system. Map courtesy City of San Antonio.

“It seems ironic that you’d be dumping tannery wastewater into the acequia that people used for drinking water,” Denton said.

True, and perhaps one reason why people didn’t live as long back then.  More than 150 years later, what once was a waterway carrying toxic wastewater into the city’s drinking supply is now a rare Confederate-era artifact.

One question officials will have to wrestle with at Friday’s meeting to discuss preservation: Who will pay for the removal, relocation and restoration of the historic find? Even in a city that cherishes its history, that will prove to be a serious present-day challenge.

Follow Robert Rivard on Twitter @rivardreport or on Facebook.

Robert Rivard, co-founder of the San Antonio Report who retired in 2022, has been a working journalist for 46 years. He is the host of the bigcitysmalltown podcast.