Beardy Splash Room?

[SlimShady]

So I have been thinking of ways to entertain my dragon while I'm at school and he stays in his cage and i am thinking of making him a "Splash Room" essentially a small shallow area with just enough water in it so he can splash around and play in the water. I'm just wondering if its possible he could drown in water that's barely a few millimeters deep and if it is safe for him to be around for a long time.
Thanks in advance!

 

[AHBD]

Hi there, it might raise the humidity too much and he also might decide it would be a nice toilet. But if the humidity wasn't a problem he'd probably run through it and enjoy making a mess. Only sickly + weak babies would drown in a few ml's of water.