Wow it's a small world frogfan. I grew up in Severna Park, but now live in Northeast OH.

Where do you live, what neighborhood or area?

I only know of like 4 decent freshwater bodies of water in Anne Arundel County(Bluffpoint, Severn, Magothy, Lake Waterford) and two of those are rivers only freshwater half the year.

The geography is not that friendly to ponds as the soil is extremely sandy in the area. What you end up with is a lot of wetland and marsh areas like you just described as water travels freely through the soils.

Bill provides sound advice about plant diversity. It will be difficult to establish several species in the presence of cattails and other reeds like phragmites. I don't think you need to add fish. Perhaps minnows would do well in there controlling mosquito larvae.

Good luck to you.