How to get different water levels in one map?

[Blue_Apples]

Okay, so imagine Ficho Tunnel's height map. How there's water one the upper level and water on the lower level, but the map doesn't flood.

How do I do that for my own map? I want to have a waterfall going from one small lake to another, but I can't do that without flooding my map :c. Does anyone know how to do that?

I probably didn't describe this as well as I could've, so if you can understand it, great! If not I'll try my best to explain it better.

[hugrf2]

In one of the tabs in map making you'll see the option "add water". Don't put anything in the little blank bar below unless you have a water texture you want to use for it. Sorry for being a little useless and not specific here, on a phone...

[Ruby1234]

If you want the water to be reflective like the ocean option though, you'll have to put WaterReflectMat in the blank before you click New Water though.