The soil has been damp to wet for the last 2 -2/12 months

Where's the water coming from? What can be done to re-route or otherwise
keep the soil from being damp all the time?

Bear in mind that poor soil condition under a big tree is a sure way to make
sure it topples over during high wind conditions, or just rots and falls
over. But at the same time you want to be careful about what you do to the
root network of the tree. So if you can figure out where the water's coming
from, make sure the efforts to manage it don't needlessly harm the tree's
roots. As in, don't whack a trench through a large part of them. Have an
arborist take a look at the situation so you don't wreck the tree.