A stretch of southbound Highway 101 is back open after a nearly 17-hour closure. The road south of Petaluma into Novato reopened Sunday afternoon. It closed to allow PG&E crews to repair a pipeline impacted by a landslide. The stretch of Highway 101 from southern Sonoma County into Marin County was originally supposed to reopen at about nine o’clock Sunday morning. But, the closure was extended by a few hours after crews discovered they had more work to do and concrete they had poured needed more time to set.