• Water radiolysis
• Water ration
• Water rationing
• Water reabsorption
• Water receptacle
• Water recirculation
• Water recirculator
• Water refill
• Water refilling
• Water reflect off
• Water repellency
• Water repellent
• Water reservoir
• Water resistant
• Water retardant
• Water retention
• Water reticulation
• Water retting
• Water reusing
• Water reutilization