here's jonathan serri reporting from the scene. >> reporter: the city of columbia is on a boil water advisory because the fresh water reservoir is over flowing. you can follow the flow of the water. it's going past the electric plant into the broad river which merges with the river to form the congarene river which will carry more flood waters downstream. this is the gervais street bridge. it's closed to traffic right now. >> and the rain/flood waters have killed at least six people in several states. new polling in the key state of new hampshire is signaling some big shifts in the race for the white house in 2016. donald trump with 20% of the votes if it were held today. carly fiorina just five points behind that with 16%. senator marco rubio and dr. ben carson tied with 10% each. on the democratic side now, senator bernie sanders leading