The board may change the purposes for which any proposed debt is to be incurred, the estimated cost, the amount of bonded debt to be incurred, or the boundaries of the benefit district or zones, if any, therein or one or all of those matters, except that the board shall not change the boundaries to include any territory which will not, in its judgment, be benefited by the district action.

For all purposes of this chapter, it is conclusively presumed that any right-of-way of a common carrier will not be benefited by the district action.