Since the roof downspout is feeding out right at the base of the tree, yes it could certainly be too much water. The planting area appears to be in a bit of a depression as well and that could be compounding the problem. While these trees like even soil moisture, especially during the heat of summer, they absolutely require good drainage. It is very possible the area surrounding the tree is staying too wet too long.

You may have the beginning of a root rot going on.

Agreed

Thank you for the quick reply.

Dave - Ottawa, Ontario

Ya, Id divert that roof water spout somewhere else. They are known to do all kinds of property damage.