Any portion of a component of the national wild and scenic rivers system that is within the national wilderness preservation system, as established by or pursuant to the Wilderness Act [
16 U.S.C.
1131 et seq.], shall be subject to the provisions of both the Wilderness Act and this chapter with respect to preservation of such river and its immediate environment, and in case of conflict between the provisions of the Wilderness Act and this chapter the more restrictive provisions shall apply.