Appear Blocks during the Game

My game is for a project and i want to have where a block appears which will stop the water from going.
i got the hang on how to make the water stop but not the block to appear.

Here is the Link, the problem is on Level 3:

Hey, I took a look but I don’t understand the question. Maybe give a few more details?

So you want to have a block show up at a certain spot? If that’s correct, maybe just add the block, and have a once trigger set its alpha to 0 at the start sow it doesn’t show up, then set the alpha to 100% when you want it to appear.

So where the water disappears i want a block to appear so it looks like the block is creating the stoppage of water.
Does this make better sense or do you want me explain more?