Section 4.50 - Applicability(a)Applicability.(1) Except as provided in paragraph (a)(2) of this section, the provisions of this subpart apply to any application for either an initial license or new license for a major project-existing dam that is proposed to have a total installed capacity of more than 10 megawatts.(2) This subpart does not apply to any major project-existing dam (see§ 4.40 ) that is proposed to entail or include:(i) Any repair, modification or reconstruction of an existing dam that would result in a significant change in the normal maximum surface area or normal maximum surface elevation of an existing impoundment; or(ii) Any new development or change in project operation that would result in a significant environmental impact.(3) An applicant for license for any major project-existing dam that would have a total installed capacity of 10 megawatts or less must submit application under subpart G of this part (§§ 4.60 and 4.61 ).(b)Guidance from Commission staff. A prospective applicant for a major license-existing dam may seek advice from the Commission staff regarding the applicability of these sections to its project (see§ 4.32(h) ), including the determinations whether any proposed repair or reconstruction of an existing dam would result in a significant change in the normal maximum surface area or the normal maximum surface elevation of an existing impoundment, or whether any proposed new development or change in project operation would result in a significant environmental impact.Order 59, 44 FR 67651, Nov. 27, 1979, as amended by Order 184, 46 FR 55942, Nov. 13, 1981; Order 413, 50 FR 11684, Mar. 25, 1985; Order 499, 53 FR 27002, July 18, 1988; Order 877, 86 FR 42714 , Aug. 5, 2021