Proposed easement on property : What reduction in resale value?

Good Morning All, the current value of our home is $750k. Queenslands' power provider, Powerlink, has utilized over 15 years and continues to do so, our driveway for access to their transmission towers, so too Gold Coast Council for maintenance. We asked for assistance to seal the surface and both have refused to assist. I am investigating options to either a) refuse all access or b) accept an easement arrangement under certain conditions. What reduction in resale value could we expect to occur, if we accepted an easement proposal to be in place on the property? Any historical evidence in your reply would be enormously appreciated. Kindest Regards, Mark