This is more of a shrub willow than a willow tree so root system will be proportionally smaller. And the 'invasiveness' is really directed by the willows water-seeking nature. Electrical lines are pretty safe :-)

except if you ever dig it up.. and hit the service.. and thank god you didnt planting it ...

i once quizzed a miss dig guy... he said.. the difference between where it is supposed to be [3 feet in your case] and reality.. can be as much as 2 feet eleven inches ...

he suggested. the electrician did what he was supposed to.. but who knows what the guy who resurfaced the yard after construction did ...

regardless... trees/shrubs do NOT attack things ... especially in regard to electric ... but in regard to water.. they will take advantage of pre-existing problems ... and that usually means old school stuff .... they really arent going to chisel their way thru pvc ... etc .. but if you have an old fashioned adobe tile sewer pipes.. where the oakum was packed in 50 years ago.. then yes.. the tree will invade ...

ken

Hey, thanks. Okay, I like your answers, and I really want to keep the plant.... So bear with me here: I had been imagining that even though the roots would certainly not be seeking water in the plastic electrical wire, that these roots would be so heavy and massive that they could possibly stress and bust the wire, kind of like root girdling damages a tree trunk; and re it being a shrub, I was thinking that it's a "shrub" more just because we cut this one back and that its roots would still be of the hefty tree it'd be if left to it's own growing pattern..... And re depth of wire, I'm rather sure the wire is pretty deep because not so far away it WAS very deep when I chopped down a 15 year old dog wood and hand dug-chopped the root ball out. The same electrical wire was well beneath all of this, a good 3 feet down and man I WAS lucky I didn't cut that one in half....... Oh, and there is indeed a sewage line leaving the house going through the backyard that I would say is 10 feet over from the plant if the pipe goes straight to the street connection as I can only suppose it does, but can't say for sure........So! Tell me again because I really want to keep the "pussy." Leave it there? It ain't gonna do me any harm????

OK, once again :-) Not all willows are trees - many are shrubs. There are even groundcover willows. Salix discolor is NOT a tree and will not have or produce a tree-sized root ball. Go ahead and plant away!

"Salix discolor is NOT a tree..."

That is NOT always the case! A really lucky Salix discolor has the potential to grow to 25' to 30' high, and many have a single trunk (although that is not really a requirement for a tree to be a tree).