Piney River (Nelson County) - 1.) The "Big Piney" (Alhambra to VA. 827 ['Perkins Mill Rd'] Woodson) (VA)
400 to 450 is a good guide to minimum flow. The upper range of flow will, of course, vary depending on individual groups' skill level and disposition.
"Bridge" rapid is the "last bigger rapid," according to Ethan Harris. It comes after paddling under a bridge. In the photo of Ethan, the level is around zero on the take-out bridge gauge.