The excess water is the problem as you stated but I have not found an evergreen that would fit this situation. The best solution would be to install drainage piping which would empty into a cistern (French drain).

Illicium may work if it is rated for your zone. Clumping, NOT running bamboo is another possibility if it works in your zone.

I have a rain garden where the plants can handle downpours or drought. If you visit my gardening blog and search for "rain garden" you can see all of the plants that I grow under those conditions. We also built a dry stream bed to channel that occasional runoff from the meadow, street and our downspouts.

Cameron

Here is a link that might be useful: my gardening blog

I have Nigra & Brabant Arborvitea in a similar situation - about 3 years now, and so far they're doing great. But mine are in part shade, & the area doesn't get very dry. About 1 year after I planted the 1st batch, a flood washed away alot of the dirt and a couple trees were leaning. I just replanted w/ more local dirt and staked the leaning ones for 1 season, and they've handled many floods since.

Our neighbor has Junipers & Cedars growing in a flood area which retains alot more water for much longer than our yard does, sometimes 48 hours, and they are very healthy. The Juniper & Cedar were already there when their house was built 20 years ago, planted by Mother Nature.

Nearby, I have Canadian Hemlock. This area floods, but drains quite quickly, usually within 1 hour. I don't know if Hemlock could handle standing water.