A portion of Chanate Road in northeast Santa Rosa is completely blocked off after a sinkhole opened up near Humboldt Street. While the surface opening may look deceptive, city officials warn that the underground cavern is actually huge, stretching up to four feet deep and 20 feet across. Public works crews and utility teams are currently on the scene assessing the subterranean damage, and there is no timeline for when the roadway will safely reo…