Deluge (UA)
Unearthed Apocrypha #1: East of Eden, p. 7.
Level 3 Evocation (Druid, Sorcerer)
Casting Time: Action
Range: 120 feet
Component: V, S, M (a vial of rainwater)
Duration: Instantaneous
You conjure a deluge of water that crashes down in a 10-foot-radius, 40-foot-high cylinder centered on a point you can see within range. Each creature in this area makes a Dexterity saving throw. On a failed save, a target takes 5d8 Bludgeoning damage and is knocked Prone. On a successful save, a creature takes half as much damage and is not knocked prone. The water then spreads across the ground in all directions, extinguishing unprotected flames on the ground within a 30-foot Radius, and then vanishes.
Using a Higher-Level Spell Slot. The damage increases by 1d8 for each spell slot level above 3.