Limitations and Recommendations for Rivers

You can add multiple rivers to the map. However, two rivers should have the same settings, if they are within the same terrain block.

You cannot merge rivers with and without the defined Flow. The river colors (Clean Type and Muddy Type) of the merged rivers should also match. Otherwise, one of the rivers within a terrain block will use river colors of another river and there will be a sharp border in the color of the river on the edge of the terrain block:

Moreover, on the banks of the river, the surface of the water and the surface of the terrain should not have the same height. (The height of the terrain should be a little bit more.) Otherwise, the border between the water and the terrain will look unpleasant:

To fix this issue, you typically need to increase the height of the terrain a little bit.