Not a horror movie. At least not in the usual sense. Laura Dunns informative grassroots ecological documentary recounts the battle between a real estate developer and environmentalists over the polluting of Barton Springs, a legendary spring-fed swimming pool in booming Austin, Texas. Unfortunately for the developer, enviro demi-god Robert Redford learned to swim in Barton Springs as a kid. Among the talking heads with Redford are then-Texas-governor Ann Richards and Willie Nelson (93 min.).