(a) Except as provided in paragraphs (c) and (f) of this section, the final array of alternatives shall include, at a minimum, the following six alternatives:
- (1) A No Action alternative.
- (2) A nonstructural alternative: An alternative that can effectively address the problem through the feasible use of nonstructural approaches.
- (3) A nature-based solution alternative: An alternative that can effectively address the problem through the feasible use of nature-based solutions (including natural systems and ecosystem processes).
- (4) An environmentally preferred alternative.
- (5) An alternative that seeks to maximize net public benefits to society. In developing this alternative, the Corps shall not consider regional economic development effects.
- (6) An alternative that is locally preferred. If this alternative differs from the net public benefits alternative, it will be required to have a comparable level of detail and analyzed using the same analytical framework as the net public benefits alternative.
- (b) The nonstructural and nature-based alternatives do not preclude consideration of these elements in other alternatives. Nonstructural measures and nature-based solutions shall be considered as components of the other alternatives in the final array, essentially providing an integrated or “hybrid” of gray (hard) infrastructure with these other measures.
- (c) The same alternative may be identified as more than one of these required alternatives.
- (d) Mitigation of unavoidable adverse effects associated with each alternative must be included in the alternative and in the analyses.
- (e) If an alternative requires changes in existing laws, regulations, or policies, those changes must be clearly identified and explained.
- (f) If one or more of the required alternatives is not included because the Corps was not able to identify a potential solution that is feasible and consistent with the purpose of the study, the study must document that decision.
- (g) The discussion of the final array of alternatives should include the primary purpose of the analysis; the geographic size of the study area; the types of impacts; the number of people potentially affected and anticipated degree of impact; environmental justice considerations; the size and location of communities potentially affected including the presence of Federally-recognized Tribes or Tribal members; and the type of data and information available from Indigenous Knowledge, collaboration, public involvement, and previous studies.