Value of a "Temporary Construction Easement"?
I am not sure where to post this question, so I am starting here.
The 3.5ac right behind my house is being developed into an 18 home development. We live the greater Seattle area.
We are the corner lot at the entrance/side of this new development (so my entire back fenceline is adjacent to the soon to be developed property.
Today, the developer came over and asked for a "Temporary construction easement" that will "not ever convey". He said they need to dig into our backyard--the last 15 feet or so, most of the length--in order to have an okay slope to protect the workers/construction of a huge underground water vault (120'x80') that will be going in for water retention for these 18 homes. He said they'll put my fence back/put up new, do landscaping in the backyard, and usually "some money exchanges hands for this sort of thing" after the vault has been constructed. They will also pay our attorney fees for an attorney of our choosing to look over the easement, etc.
In my head, I would like for them to put in a rockery/retaining wall on the edge of my property that is a "drop off" to the sidewalk below, and will be "frontage" along the road that their new development comes off. He seemed amenable to that (it is really hard to maintain. Almost straight up and down, dirt/clay with grass that can't be mowed because of the steepness, so we go out there with a weed-whacker regularly until our battery dies). Cleaning up this slope, with rockery, would probably be good for the looks of their development too.
But, my spouse isn't convinced that the rockery actually adds much value for us, and wonders if we should ask for cash instead. I'm thinking they can do the rockery for much less than we can, due to them already having the huge equipment here to dig out that huge vault...so for them, the expense isn't as great as it would be for us to put in the rockery ourselves.
But, really, what is an easement like this worth?
And, any advice from those out there about Temporary easements, in general?