the expansion is designed and built in accordance with the procedures and standards established in section 650.101 of title 23, Code of Federal Regulations, and the following as they may be amended from time to time; and

the boundaries of the Floodway are adjusted to account for changes in flows caused, directly or indirectly, by the expansion;

projects for the study, management, protection and enhancement of fish and wildlife resources and habitats, including, but not limited to, acquisition of fish and wildlife habitats and related lands, stabilization projects for fish and wildlife habitats, and recreational projects;

the establishment, operation, and maintenance of air and water navigation aids and devices, and for access thereto;

projects eligible for funding under chapter 2003 of title 54;

scientific research, including but not limited to aeronautical, atmospheric, space, geologic, marine, fish and wildlife and other research, development, and applications;

assistance for emergency actions essential to the saving of lives and the protection of property and the public health and safety, if such actions are performed pursuant to sections 305 and 306 of the Disaster Relief Act of 1974 1 (42 U.S.C. 5145 and 5146) and are limited to actions that are necessary to alleviate the emergency. Disaster assistance under other provisions of the Disaster Relief Act of 1974 1 (Public Law 93–288, as amended) [42 U.S.C. 5121 et seq.] may also be provided with respect to persons residing within the Floodway, or structures or public infrastructure in existence or substantially under construction therein, on the date ninety days after October 8, 1986: Provided, That, such persons, or with respect to public infrastructure the State or local political entity which owns or controls such infrastructure, had purchased flood insurance for structures or infrastructure under the National Flood Insurance Program, if eligible, and had taken prudent and reasonable steps, as determined by the Administrator of the Federal Emergency Management Agency, to minimize damage from future floods or operations of the Floodway established in the chapter;

other assistance for public health purposes, such as mosquito abatement programs;

nonstructural projects for riverbank stabilization that are designed to enhance or restore natural stabilization systems;

publicly or tribally financed, owned and operated compatible recreational developments such as regional parks, golf courses, docks, boat launching ramps (including steamboat and ferry landings), including compatible recreation uses and accompanying utility or interpretive improvements which are essential or closely related to the purpose of restoring the accuracy of a National Historical Landmark and which meet best engineering practices considering the nature of Floodway conditions;

compatible agricultural uses that do not involve permanent crops and include only a minimal amount of permanent facilities in the Floodway.