A wall of water springs into existence (Concentration, 6 rounds). The wall is up to 300 ft long, 300 ft high, and 50 ft thick. When cast, each creature within the wall's area makes a STR save or takes 6d10 Bludgeoning damage and is swept away. Each subsequent round, the wall moves 50 ft and creatures caught must swim (Athletics DC 20) or take 5d10 damage. When the spell ends, the water floods down.