I've been wanting to do a desert survival game in which I build a fortress around a desert well, but rivers keep appearing around the map. It ruins the mood - why bother with the whole "fortress to defend the precious water source" if the desert has water everywhere? I've been trying different settings to get rid of the water but the best I can do is to lava oceans or set the sea level super low but both have their own problems - rivers of lava are neat I guess, but not really my idea for what I wanted in the setting, and if I leave the sea levels low I get a bunch of odd "rivers of grass" around the map. Any way to get the effect I desire in Vanilla? (and if not, any mods that do this one, limited thing?)
(Comment concerning deleted post removed - BigAlanM)
As for the OP's question, there is unfortunately no way to get rid of rivers, which IMO was one of the oversights when they added the Customized settings and would have been easy to add. You can get around it somewhat by manually editing the preset for a bigger river size (actually, this controls the distance between rivers) than the slider allows, which will put them so far apart you may as well never find one. For example, a river size of 6 (this was actually the river size in Large Biomes until 1.8, which changed it to 4 with a maximum of 5 on the slider) will space rivers 4 times further apart; a size of 8 will space them 4 times further apart again, or 16 times the default, and so on (each step is twice the size).
I don't know if there is a limit or any issues with extreme values but the exponential nature quickly increases the distance between rivers to far beyond what you can practically travel in Survival (provided you spawn between rivers, not next to one); a size of 14 would make rivers 1024 times further apart than default, or hundreds of thousands of blocks between rivers.