Intensive Survey and Testing Associated with the Rediscovery of the Acequia Madre and Alamo Dam, San Antonio, Bexar County, Texas




Ulrich, Kristi M.

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Center for Archaeological Research, The University of Texas at San Antonio


In November and December of 2010, the Center for Archaeological Research (CAR) at the University of Texas at San Antonio (UTSA) was contracted by Ford, Powell, and Carson, Architects and Planners, Inc. to conduct intensive pedestrian survey and testing in search of the Acequia Madre (41BX8) and Alamo Dam on the grounds of the Witte Museum. Archival research was conducted to search for information that would pinpoint the location of the dam and irrigation ditch. Historic maps were consulted and overlaid on current aerials of the project area to offer insight regarding the potential location of these features. The investigations consisted of the excavation of nine backhoe trenches (BHTs) and three auger tests. Each backhoe trench extended to at least a depth of 1.5 meters below the surface, although most exceeded this depth. The auger tests extended to a maximum depth of 1.5 meters. A portion of the Alamo Dam was located in BHT 7, adjacent to the current channel of the San Antonio River. The dam consisted of large stacked limestone blocks. It appears that the top of the dam was likely sheered off during the 1930s during the construction of the stone wall lining the channel of the river. Evidence of the Acequia Madre (41BX8) was found in BHT 9, located in the grassy area in front of the Pioneer Hall between Curiosity Lane and Broadway. This trench extended to a depth of 12 feet below the surface before encountering the water table. Two ditch outlines were noted in the profile of the trench, one undercuts the other. They represent two paths of the acequia, one older than the other. Trenches were photo-documented and mapped prior to being backfilled. A small number of artifacts were collected at the site and returned to the CAR laboratory for processing and curation. All project related documentation and artifacts are permanently curated at the CAR facility.



archaeological investigation, archaeology, Texas archaeology, archaeological surveying, excavations, Bexar County, San Antonio