(a) Where an environmental review is required under the National Environmental Policy Act of 1969 (NEPA) (42 U.S.C. 4321 et seq.), and 24 CFR part 50 or part 58, compliance with this part shall be completed before the completion of an environmental assessment (EA), including a finding of no significant impact (FONSI), or an environmental impact statement (EIS), in accordance with the decision points listed in 24 CFR 50.17(a) through (h), or before the preparation of an EA under 24 CFR 58.40 or an EIS under 24 CFR 58.37. For types of proposed actions that are categorically excluded from NEPA requirements under 24 CFR part 50 (or part 58), compliance with this part shall be completed before the Department's initial approval (or approval by a responsible entity authorized by 24 CFR part 58) of proposed actions in a floodplain or wetland.

(b) The categorical exclusion of certain proposed actions from environmental review requirements under NEPA and 24 CFR parts 50 and 58 (see 24 CFR 50.20 and 58.35(a)) does not exclude those actions from compliance with this part.