@sozobe,
Yowie.
Me, I always specified trees with future mature growth not at/near the height of power lines, though deeper within a yard I'd specify trees to mask power pole view and to some extent view of the lines. I'm pretty used to power lines, given I've usually lived in old neighborhoods and so have many of my/our design clients. Lines are generally buried here in Abq., and I'm getting used to a clear look at gorgeous skies.
Sometimes trees are already there, and some reasonable pruning, preferably by an arborist or other expert, can still save the form of the tree. Tree butchering, ask me about Los Angeles, can bring tears of rage from moi.
Have you checked your site plan (available at the city if you don't have it) to confirm the right-of-way easement dimensions?
I'll be interested to see how you all deal with this. I guess I'd think about trying to get some sort of stop order until the neighborhood can discuss this with the city. Is there a neighborhood association already in place? I might also go the the area councilman/woman and the local newspaper.
Meantime, in LA, land of thousands of trees chosen for street trees incorrectly in the past, there has been a long impasse on fixing hellacious city sidewalks. Just in the last short time, there's a lawsuit by the key disabled group (I forget the name) that quite possibly will get the city to pay for necessary removals, to the tune of millions. As this problem has gone on and on and on and on, the city has become far less walkable than it was, say, forty years ago.
I remember once making notes re dangerous sidewalk situations when I was on one of my usual walks between my house and the far end of the Marina Peninsula, which is actually part of Venice, which is part of LA. I never did anything about it, both being busy and because those sidewalk troubles were typical in a lot of the city.