Larian Studios Forums Divinity - Original Sin Divinity Original Sin - Mods Messing around with level design - results so far

You can find different types of water planes in Root Templates. If you expand the list to Nature-->Water there's all sorts of water planes.

If it's too small initially when you add it, you can change the scale in the sidebar.

Oh, and there's also water paint in the AI grid window - allows you to paint that surface water your characters can walk on, and I believe it would also be possible to electrify it in the game.