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

(a) General considerations; nonstructural alternatives

In the survey, planning, or design by any Federal agency of any project involving flood protection, consideration shall be given to nonstructural alternatives to prevent or reduce flood damages including, but not limited to, floodproofing of structures; flood plain regulation; acquisition of flood plain lands for recreational, fish and wildlife, and other public purposes; and relocation with a view toward formulating the most economically, socially, and environmentally acceptable means of reducing or preventing flood damages.

(b) Non-Federal participation through nonstructural alternatives; limitation

Where a nonstructural alternative is recommended, non-Federal participation shall be comparable to the value of lands, easements, and rights-of-way which would have been required of non-Federal interests under section 701c of this title, for structural protection measures, but in no event shall exceed 20 per centum of the project costs.

Nonstructural Flood Control Policy

Pub. L. 104–303, title II, § 202(d), Oct. 12, 1996, 110 Stat. 3675, provided that:

“(1) Review.—
The Secretary shall conduct a review of policies, procedures, and techniques relating to the evaluation and development of flood control measures with a view toward identifying impediments that may exist to justifying nonstructural flood control measures as alternatives to structural measures.
“(2) Report.—
Not later than 1 year after the date of the enactment of this Act [Oct. 12, 1996], the Secretary shall transmit to Congress a report on the findings of the review conducted under this subsection, together with any recommendations for modifying existing law to remove any impediments identified under such review.”