This legislation, known as the Hydropower Licensing Affordability Act, aims to streamline and modernize the federal hydropower licensing process. It specifically amends the Federal Power Act to introduce new limitations on the conditions that can be imposed on hydropower projects. One key provision modifies Section 4(e), ensuring that conditions set by federal reservations must be directly related to and reasonably mitigate the direct adverse effect of a project on that reservation. Another significant change in Section 18 restricts the prescription of fishways, requiring them to specifically reasonably mitigate the direct adverse effect of the project on fish populations in the applicable river system. These amendments collectively seek to narrow the scope of mitigation requirements, thereby making the licensing process more efficient and affordable.