Wont work yet champ. Water flow physic's are not activated or coded for yet so we have no flow yet mate. But it is in the works for this year. Unfortunately if you dig around the edges of lakes rivers or any water body atm, you get jaggered ends to the water texture in some spots which looks completely wrong , like a frozen lake at best. Will be very cool though when fluid flow physics come to Empyrion, it will change quite a few planets, and lava, well lava could take on a whole new meaning, and maybe on some planets huge volcanoes can be used to deposit ore instead of meteorites and you could have random volcanoes blow there tops at random times making living anywhere near them idiotic at best ! Yes I expect fluid will change alot of things for the better.
I look forward to it. Along with eventual Implementation of the REAL Water & Lava, it'd be cool to be able to be able to move the Liquids around as well, especially being able to move Water around to have more choice in being able to have your in-Base H2/O2 Generator & Water Generator located. (Also be cool to be able to move Aestus Slime around too.)