Wherever in this chapter or in any city charter a board of officers is authorized to take land by eminent domain under chapter seventy-nine, in connection with the laying out, widening, altering or relocating of a public way, such board of officers shall be authorized to take an easement in land adjoining the location of the public way consisting of a right to have the land of the location protected by having the surface of such adjoining land slope from the boundary of the location.
Massachusetts Legal Code