After the tree mentioned in the other note, where the river splits into some channels: keep to the right, maneuver close to a bush and pick the rightmost channel which is clear. Do not go straight on where most of the water is flowing because it's one big strainer choked full of logs

1 km ca after the Vogna’s confluence a large tree block completely the way. Stop in advance and portage.
Few hundreds meters later the river split in some different channels and may they can be unrunnable due log jam