there are dozens of small to medium streams that feed into the bay and lake. All it takes is a big t-storm to roll through and everything from trees to landscaping timbers finds its way into the water. The prevailing current is west to east so it all ends up washing up on shore or going over Niagara Falls eventually. In the mean time it's not uncommon to see dead heads floating.

I remember taking out a prop and driveshaft on the outboard of our ski boat many years ago. I missed the USCG warning about 4x4 timbers floating just at the surface in the bay. The bigger stuff is usually just in the lake.