How do I cast a spell on the ground?

[Sciophyte]

I need to cast Kalikke's Water Blast on a fire... but I can't see any way to do this. Any advice? Thanks!

[Gravedancer]

click water blast. Click on ground. When clicking on water blast from the action bar, make sure you click the > and then choose which version of water blast (regular, not torrent, etc) you want.

[Sciophyte]

That did it. Thank you!