free fallfree fall weirfree flowfree flow canalfree flow conduitfree flow speed or ffs or ffsfree flow tunnelfree flow tunnel developmentfree ground waterfree heightfree marginfree overfallfree overflowfree penstock or exposed penstock or exposed penstockfree spillwayfree standing towerfree steered vehiclefree vortexfree waterfree water surfacefree weirfreeboardfreeditefreestone or freestonewater or freestonewaterfreezingfreezing up heavalfreibergitefreieslebenitefreikssonitefreirinite or lavendalan or lavendalanfrench drainfrenuliniformfrenulumfrequencyfrequency diagramfrequency distribution curvefrequency responsefreshfreshetfreshet canalfreshwater icefresnianfresnoitefreudenbergitefreyalitefriablefriable earthfriable surfacefrictionfriction berccia
