; and (C) prescribe procedures to implement the policies and requirements of this Act— (i) to the extent permitted by law; and (ii) in accordance with the procedures described in paragraph (3). (2) Determination of floodplains The head of an agency shall, when determining whether an agency action will take place in a floodplain— (A) use— (i) the elevation and flood hazard area, as determined by— (I) a climate-informed science approach that— (aa) uses the best available actionable hydrologic and hydraulic data and methods; (bb) integrates current and future changes in flooding based on climate science; and (cc) includes an emphasis on whether the agency action is a critical action; (II) the freeboard value, reached by adding an additional— (aa) 2 feet to the base flood elevation for an agency action that is not a critical action; and (bb) 3 feet to the base flood elevation for an agency action that is a critical action; or (III) any other method that is identified in any amendment made to this Act; or (ii) an area that has a 0.2 percent chance of flooding in a year; and (B) rely on— (i) the best available information