How to create rivers in UE5.3?

Hello,

I’m using static meshes for my terrain, so I don’t know if I can use the landscape tools. I am wondering how would I go by creating rivers that start at a certain height and end in another lower height.

These rivers will each start and end at different heights. I know of the tool “Water body river” but I do not know if it would work well on static meshes.

Also, is there a way to do this using masks? If I had a mask with the rivers of my game, could I use the RGB of a texture to texturize water?

@ Demenzun Media
I am trying to use TerreSculptor 3.0 to mask rivers, and when I load a mask that I made with QGIS I get the following image:

The green dots should be connected, forming streams.
One issue I see is that the mask is displayed differently depending on zoom levels, but only in the mask editor (similarly happens in QGIS):

Zoomed out view:

Zoomed in view:

I think the 3d viewport is displaying the zoomed out version. It should look like the second, when I have it zoomed in. Will this be a problem when exporting to UE?