Water levels in lakes and rivers are at different altitudes.

[Coyote_One]

This specific screenshot was taken in grid DA17 however all of the water in the map seem to raise and lower in altitude. Some spots are higher than others. Some lakes are at 80 feet and the middle of the lake is 40 feet.

A minor gripe but water and gravity don't work like that  

Hopefully your team is aware of this, thank you!