Question #1... How far is it from the top of the dam to the water? How much freeboard are you clearing?

#2....Any possibility of burning off that little stuff, so you can see what needs to be cut off at the base?

Observation.....Buy a brushcutter, son! This is your perfect opportunity for another tool purchase. Equip it with a tri-blade, and get after it. I can reach 4' with mine, but can't tell if that would be enough for all of what you have...I know it would get a lot of it, and you would be amazed at how quick it is.

I have a DR brushcutter also, but for this kind of work the hand-held unit has it beat all to pieces. As I tell those who ask: This kind of job won't get done without losing copious amounts of blood or sweat. Oftentimes it's both.

"Forget pounds and ounces, I'm figuring displacement!"

If we accept that: MBG(+)FGSF(=)HBG(F1)
And we surmise that: BG(>)HBG(F1) while GSF(<)HBG(F1)
Would it hold true that: HBG(F1)(+)AM500(x)q.d.(=)1.5lbGRWT?
PB answer: It depends.