[CzechTexan]

My rivers got fixed by using the coastline adjusting tool.
This is how I did BurmaLower with similar type of mountainous geography.

I enlarged MapH to layer over the large mapC (memory intensive) and added another layer to draw on.
Drew the rivers in valleys, RGB=0, width of #5 pencil in GIMP (smaller size or blurred rivers would not show water.
Deleted MapH.
Merged invisible layer with mapC.
Noticed some rivers in the deep gorges of Burma were on sides of mountains.
Used the Coastline Tool to bring the land (1 pixel around rivers and ocean) down to the level of the water.
This fixed MapH so that water does not go on sides of mountains.
Excellent tool.