OK, so: It looked like the river near Telso was going up into the hills from the lake and then down the other side of the hills. Is the lake supposed to be at high elevation as well? If so I totally misunderstood the map.

I'd name the city across from Marita with a second name. Think San Francisco/Oakland. I suspect this would happen naturally.

Here are some great views of salt marshes from above, and you can also look at marshy places on Google Maps in satellite view for reference (try 31.361846,-81.466026).