JULY 13, 2020
I uploaded the map I created to my realms account so that people who wanted to help could see it and we could have meetings to discuss ideas. World Painter only works with an older version of Minecraft and Realms only works with the newest version, so any changes we made in Realms would not be permanent until I was completely finished with what I could do in World Painter.
Lik came up with the idea of having rivers between the "continents" and a lake in the middle. I started playing with this idea in World Painter, terraforming them to "flow" from the edges of the map to a lake in the middle by gradually lowering the terrain. Since the continents had to stay level, this created a slight valley as a river got closer to the middle.
Near the edge of the map.


Junction of two rivers.
River in more of a valley near the middle. In middle rivers will flow into inland sea.

