BEE CAVE, Tex.NEARLY two decades ago, Gene and Linda Lowenthal, who were living in Austin, decided that they would eventually want to move to the wide-open countryside. They bought 58 acres in this small town in the Texas Hill Country, about 45 minutes west of Austin, built a small house and moved here in the mid-’90s, finally free of noise and sprawl. That freedom lasted about nine years. Then, bulldozers started appearing on hillsides once covered with live oak and mesquite trees. Houses and traffic lights popped up on once-forlorn roads leading to their home. Plans for a water line...