You can actually place ice over a block in creative mode, do the command - /gm s , and then break the ice in survival mode which will make water. If you need to break a large amount of ice, enchant a diamond pic with efficiency 5 and it should break the ice almost instantaneously. If you already knew this and just wanted to make it even easier then SUPPORT.
I understand why they made it so water is still instead of flowing, but did this still cause lag? It would be really nice to have it back, support.
There is a simple way to get water for those of you who don't know. Put Ice while in creative mode Go in /gamemode s Break the ice :>