A late arrival to winter is taking hold, and every creek, river and waterfall is acquiring its own personality. Some, like Silver Falls in the remote Santa Cruz Mountains, are roaring, having been jump-started by 7 inches of rain in the past week. Others, like Carson Falls in the Marin Watershed, have been brought to life in recent days, including 5.7 inches of rain a week ago Monday, with more on the way Thursday, Friday and early next week.