Well, I am now informed. I just spoke to our realtor,
The buyers want the property and they are willing up to a point to accept the city's stipulations, which are a retaining wall and a retaining pond to deal with the ecology and the creek at the back of the mutual properties.
The drawback: the costs and how much of our land will be eaten away in this construction. If it eats away an acre of our three and costs them $60-80,000, they can't take it.
In short, we will know nothing more for at least two weeks when our buyers and the city have a meeting. And so, I have two weeks to dig myself further into debt, at which time we may lose the sale.