biome creek flour flume historic mill natural environment Natural landscape nature nature reserve Old-growth forest Riparian zone river rustic water water resources watercourse wood cascade Fluvial landforms of streams Forrest landscape Mountain River outside hiking stream vegetation waterfall waterway bank hut norway plant shed spring village wooden cornwall countryside England english farm fast flowing Great Britain hillside rocks boulders moss mossy trees woodland Arrowtown branch cloud flow green leaf leaves mountain natural new zealand River Arrow Salix sky tree willow