33 U.S.C. § 701b–11 — Flood protection projects

(a) When a Federal agency surveys, plans, or designs a flood-protection project, it must consider nonstructural alternatives and seek the most economically, socially, and environmentally acceptable way to prevent or reduce flood damage. Alternatives include (1) floodproofing structures, including raising them; (2) regulating floodplains; (3) acquiring floodplain land for recreation, fish and wildlife, or other public purposes; (4) relocation; and (5) using a feature described in section 2289a(a). (b) If a nonstructural alternative is recommended, the non-Federal contribution must be comparable to the lands, easements, and rights-of-way that would have been required for structural protection under section 701c, but may never exceed 20 percent of project costs.