Barton Springs Pool

[citation needed] Spanish explorers discovered the springs in the 17th century, and around 1730 erected temporary missions at the site (later moving to San Antonio).

[citation needed] In 1837, before the incorporation of the city of Austin, the area was settled by William ("Uncle Billy") Barton, who named three springs after his daughters: Parthenia, Eliza, and Zenobia.

He and subsequent owners of the property recognized its value as a tourist attraction, and promoted it vigorously, thus leading to the swimming hole's lasting popularity.

The pool has been closed to the public a number of times since the 1980s due to unsafe levels of fecal coliform (E. coli) bacteria in its waters.

Contamination is usually worse after heavy rains due to the flushing of the effluent of upstream subdivisions into the Edwards Aquifer recharge zone which feeds the springs.

SOS became a force in Austin municipal politics, leading to many "green" initiatives involving environmental issues in addition to those of the springs.

In 2007 he and Terrence Malick co-produced The Unforeseen, a documentary highlighting environmental impact to the Edwards aquifer from the surrounding real estate subdivision.

[9] After closing the pool for 90 days, officials from the CDC, USEPA, State of Texas and the City of Austin deemed it safe for swimmers.