Tidecall

You shoot forth a blast of magical water in a 15 foot cone in front of you. Each creature within that range must make a strength saving throw, taking 3d8 bludgeoning damage and knocked prone or pushed to the back of the cone  (your choice) on a failed save, or take half as much damage on a successful save.

Using a Higher-Level Spell Slot. The damage increases by 1d8 for each spell slot level above 2.