With a high water table and big evergreens, blowdowns will be a concern. What's the wind like where you live?
Mike

Sweet Bay Magnolia can handle wet areas. Never thought of it as a screen, but perhaps it could be as it is evergreen. They are not particularly big trees, maybe 35' or so tall. The ones I've seen in north Louisiana are either growing by a creek or in a boggy wet area.

Chamaecyparis thyoides, Thuja occidentalis, and Picea mariana would likely work. Pitch and Loblolly Pines are also possible candidates.

Around here, Hemlock grows quite well with wet feet from November to May.

Thank you for the responses.

Yes, it is windy at times, good point.

Certain cultivars of Magnolia grandiflora are supposed to be borderline hardy here but haven't tried due to the desiccating winds. I hear that ripping winds damage the leaves enough, that if it survives the cold it will always look ratty.

could you be a little more specific as to where you are ...

and what is the soil structure .. beyond moist ...

and what does 'windy at times' mean .... are you in hurricane territory??? ... well canadian hurricanes???? .. probably not that i know of....

ken