An excavation at Brackenridge Park has unearthed irrigation systems built to serve the first settlers of San Antonio.
The find offers opportunities to study indigenous peoples and provides fuel for the UNESCO consideration of the San Antonio Missions as a World Heritage Site.
Archaeologists have long been aware of the existence of the 300-year-old irrigation systems, and even had maps and data from Spanish engineers who documented their work.
The April 30 discovery of the oldest-known acequia and a later one further north bring a new wave of excitement and storytelling to the San Antonio River where it travels through Brackenridge Park.
"It was the very first one. That’s why it was called the Acequia Madre. It was the largest one and fed the largest acreage," said UTSA Archaeology Professor Steve Tomka.
Tomka told reporters that the Acequia Madre and diversion dam were built in 1719.
"We know because the Spanish were awesome record keepers. They were very much into documenting everything that they did, and so they wrote it down in the accounts, actually when the building of the dam and the acequia started," he said.
Acequia Madre was ultimately constructed in a southeasterly direction across what is now Broadway and made a turn just below Hildebrand then headed south to the Alamo to water crops and provide water to settlers of Mission de Valero.
Later, the waterway came to be called the Alamo Acequia.
The San Antonio River Authority has had a contract with UTSA for excavations in advance of the city’s work to add hike and bike trails and other improvements to the park.
SARA General Manager Suzanne Scott said the two new finds are on the Museum Reach Park segment yet to be constructed.
"Many of our community knows that we are working to have a contiguous hike-and-bike trail all the way from what we’re celebrating here at the headwaters and the Upper Labor area all the way down to Mission Espada," Scott said.
The Upper Labór Acequia, slightly upstream from Acequia Madre, is where a later 1800s German restoration of the original Spanish damn was unearthed.
Leilah Powell, executive director of the Brackenridge Park Conservancy, said the two discoveries together give a clearer picture of the development of the area.
She said the German construction is obviously different, with squared-off, blocks as opposed to the more rubble-type masonry used in Spanish construction.
"The interesting thing, also from my perspective in the conservancy, is that this stone was probably quarried up in the quarries that now are the zoo and the Sunken Gardens. So most of the stone in the park came from the park itself which was the municipal quarry and part of that Spanish land grant," Powell said.
“So really you’ve got this entire history of the utilization of the river and our growth as a community. And when you couple this with the other water resources here in the park - with the fact that the water system started here in the 1870s, with the fact that there was a tannery and a steam saw mill here - you can understand how absolutely vital to our founding and growth the river is. And that’s a story you could not tell a year or two ago because the resources just weren’t exposed," she said.
Powell said she envisions an interpretive area and outdoor classroom to give local students a tangible look at all of the resources and different time periods of settlement and growth of the community.
"The city has bond dollars that are going to be devoted to this area also," she said.
"We don’t give enough credit to the Spanish and the German architects who were involved in the irrigation system. And we’re learning that the basic principles of hydrology and engineering really were known by them. Their knowledge was equal to our knowledge today, which is pretty amazing," Tomka said.
Each of the more southerly missions built their own acequias as new settlers arrived.
Tomka said the latest discoveries in Brackenridge Park give archaeologists a chance to learn more about the Spaniards who invaded the area and the indigenous people who were forever changed by mission life in San Antonio.