What kind of retaining wall? How high is it?

It's about 4-5 foot high, I'm not sure of the material, but it's some
kind of stone.

A properly engineered and
installed retaining wall can last forever and require little to no
maintenance.

We spoke to the town engineer this morning he said that the have never
had any complaints about erosion or damage in that development to
retaining walls. He said he would be happy to come out with us before
closing and inspect it then as well as at closing.