See interesting mod with same idea: https://mods.factorio.com/mod/Sparkletrons_Terraformers

/// /// /// Support on Patreon: darkfrei /// /// ///

Version history:
0.1.1 - fixed problem with offshore pump; starting area is not round anymore (added metaball)
0.1.0 - reworking map generation for new maps
0.0.5 - new maps have bigger rivers; added support for Alien Biomes
0.0.4 - added support of NiceFill, now fords (river crossings) have 0.7 speed modifier.
0.0.3 - added fords (river crossings), new map generation for new games.
0.0.2 - rivers have nice borders (migration)
0.0.1 - first release

Can be good with:
platforms https://mods.factorio.com/mod/platforms
CanalBuilder https://mods.factorio.com/mod/CanalBuilder
Beautiful Bridge Railway https://mods.factorio.com/mod/beautiful_bridge_railway
Shallow Water https://mods.factorio.com/mod/shallow-water