As pointed out, Lake Harmony has a large inflow river with no obvious outflow, in addition to Green, Mirror, and Gelenor, which have neither inflow or outflow (which could be reasonable if they are just catch basins for precipitation).

Also, the delta at the end of the Deadwater River seems "backwards" in that delta are caused by the deposition of sediment at the mouth of a river, and tend to grow out into the water body, not be cut back in as channels as shown.

Lovely map though, nice colours and a good coastline.

-Rob A>