Like so many other questions, the answer is "it depends".
A tree on the dam now is a problem and the same tree in twenty years is going to be a bigger problem. It depends on how big of a problem you are willing to tackle now or later.
It depends. Are you going to own the pond for 5 years or 50 years?
The tree problem will not go away and will only get worse. I'm in the exact same problem with several pines that take two of us to get our arms around. I've got some tools for the project and will start stumping them out maybe next year. The plan is to go slow and methodical. I'm looking at one of these for a mini-excavator (
http://www.excavatorthumb.com/stumper_610k-tree-stumper-and-rake-for-mini-excavators.php) to help get the roots out without having to dig bunker sized holes in the dam with a standard bucket.
-RFL
