San Antonio Spring (The Blue Hole)

San Antonio Spring, the historic source spring of the San Antonio River, has for centuries provided millions of gallons of crystal clear spring water daily to generations of Native Americans and early Texas settlers. The San Antonio River begins just south of this point, near the campus footbridge, where Olmos Creek and the San Antonio Spring flow come together and, supplemented by hundreds of smaller springs along the way, begin the journey to the Gulf of Mexico. At one time the spring's daily flow was said to be so strong that it produced a geyser many feet into the air. In the 19th century, banker and philanthropist George Washington Brackenridge purchased this property and established the first San Antonio Water Works, adding the concrete rim around the spring, which goes deep underground to the southern boundary of the Edwards Aquifer in the Olmos Basin, to control the water flow. Over time, wells and pumps south of the Brackenridge property made the Water Works less than lucrative and also reduced the natural spring flow. In 1989, the University added the current walkway to the spring and the natural limestone ledge, making the spring more available to the campus and general community without the danger of accidentally falling into it. The stones used, with the natural indentations in the limestone, are examples of the limestone formation of the Edwards Aquifer, San Antonio's sole source of pure drinking water. In recent years San Antonio Spring is frequently dry except after heavy rains, and natural flow begins when the aquifer water table is around 676 feet above sea level. This source of pure water attracted settlers in prehistoric and historic times, and they left rich archaeological resources for future study. San Antonio Spring, Brackenridge Villa, and the five distinct Texas Archaeological Landmarks west of this spot are on the National Register of Historic Places as the Source of the River Archaeological District, and these sites are protected by state and federal law, with fines and penalties for tampering with protected sites or removing prehistoric or historic artifacts.

Alamo Heights, Texas · United States