The sinkhole that appeared a few miles south of Grass Valley and threatened the viability of Highway 49 has been contained and is being managed, transportation officials said. “There has been no traffic interference,” said Rochelle Jenkins, a spokeswoman for Caltrans. “We’re lucky to have a third lane in the area.” The sinkhole first developed Dec. 5 after a foot of rain hammered the area over a four-day period. “There was a huge amount of water that fell in a short amount of time,” Jenkins said. The rushing water found its way into a crack in a culvert alongside the …