Here's a list of moisture tolerant grasses, from Bluestem:

MOISTURE TOLERANT
Alopecurus pratensis 'Aureovariegatus'
Calamagrostis acut. 'Karl Foerster'
Calamagrostis acut. 'Overdam'
Calamagrostis hakonensis
Carex species - most
Chasmanthium latifolium
Deschampsia cespitosa - all
Elymus magellanicus
Festuca mairei
Juncus - all
Luzula species - all
Miscanthus 'Giganteus'
Miscanthus sinensis & cultivars
Molinia - all
Panicum virgatum & cultivars

Here is a link that might be useful: Bluestem

Hey Jen,

Good list from Donn.

Key factor is how much moisture. Moisture tolerant means that they can take some wet periods without much detriment, but constant wet toes is another thing altogether. If it is constantly soaked, neither the Miscanthus nor the Pennisetum will do that well. They both prefer well-drained soil. Is the area shaded as well? That would be another strike. If it is sunny, but wet, they have a better shot at success. I'd give them a try and see how they do.

Other plants you could try would be Acorus (sweetflag), Cyperus, Taro (Elephants Ear), Juncus (rush), Cannas, Irises, bamboo, lots and lots of sedges, rushes, and grass-like plants that love wet feet.

It really depends on how wet is wet...lol.

Good luck!

Here is a link that might be useful: Moisture Tolerant Plants

With some of the grasses it won't be summer/spring/fall wet that they might hate but a really wet winter combined with your cold weather could be very bad. From my experiences Pennisetums would be particularly unhappy.
So ... I actually have a spot in my dry sandy garden that is moist/damp all year round.
Panicums are .. ok but flop with too much moisture AND are far more prone to rust in these conditions.
Miscanthus floridus/giganteus .. loves it!
Arundo donax ... loves it!
and you could have clumps of Carex elata 'Aurea' which absolutely hates dry condions.
Acorus species are fabulous
Carex glauca (flacca) & Carex muskingumensis

There are lots of others as Donn & Grass guy have mentioned but these are the ones that are thriving in my damp spot.
Of course most bamboos would love those condions too but, that is another forum .....
a.