18 C.F.R. § 16.5
(a) Access. If a potential applicant for a new license, subsequent license, or nonpower license for a project has complied with the first stage consultation provisions of § 16.8(b)(1) and has notified the existing licensee in writing of the need for and extent of the access required, the existing licensee must allow the potential applicant to enter upon or into designated land, buildings, or other property in the project area at a reasonable time and under reasonable conditions, including, but not limited to, reasonable liability conditions, conditions for compensation to the existing licensee for all reasonable costs incurred in providing access, including energy generation lost as a result of modification of project operations that may be necessary to provide access, and in a manner that will not adversely affect the environment, for the purposes of:
(b)