Lots of other options for the duck blind, depends how long you wanna wait, how wet it really is, etc. Like Kanlow switchgrass & CIR switch can tolerate some moist areas. not as tall as EW obviously. Not sure if Miscantheus would tolerate wet? If it were me, I'd look into some bottom ground shrubs. even incorporate some different types of willows among some thicker low-land shrubs. Take the "shotgun approach" and try several different things and also things that have different maturity timeframes involved. If it's just duck blinds, not a ton of area I bet and be easy to do some cool things for cover.