[Rathji]

It has been a while, but when I ran a landscaping company our policy was we wouldn't plant anything other than grass above a utility right of way or change the grade more than a certain amount (like 6 inches maybe?). We might have been playing it safe because when we first started we got stung when a bitter neighbour complained and we had to redo a section of retaining wall that raised grade about 8 -10 inches above the ground.

Trees are a bad idea in general, but evergreens are the worst of the bunch because they are drought resistant because they have a taproot that goes deep and will cut through anything it comes in contact with. If you do want to risk trees then use shrubs or smaller trees (as in their mature size, not the size you buy) and flowering trees tend to have a shallower root system.

The only time I saw anything said about it that I know is when a neighbour complains or what you have done has buggered up the surrounding property. One time a lady had a small retaining wall she had build up against her swale in the back yard and the developer had an 8 foot retaining wall on the other side that was bulging. They blamed it on her little wall that couldn't have been higher than a foot and she was forced to foot a pretty big chunk of the repair bill and then pay us to fix her yard afterwards.