US Code

Public Law 119-73 (01/23/2026)

33 U.S.C. § 2318

Flood plain management

(a)

Exclusion of elements from benefit-cost analysis

The Secretary shall not include in the benefit base for justifying Federal flood damage reduction projects—
(1)
(A)
any new or substantially improved structure (other than a structure necessary for conducting a water-dependent activity) built in the 100-year flood plain with a first floor elevation less than the 100-year flood elevation after ; or
(B)
in the case of a county substantially located within the 100-year flood plain, any new or substantially improved structure (other than a structure necessary for conducting a water-dependent activity) built in the 10-year flood plain after ; and
(2)
any structure which becomes located in the 100-year flood plain with a first floor elevation less than the 100-year flood elevation or in the 10-year flood plain, as the case may be, by virtue of constrictions placed in the flood plain after .
(b)

Flood damage reduction benefits

(1)

In general

In calculating the benefits of a proposed project for nonstructural flood damage reduction, the Secretary shall calculate the benefits of the nonstructural project using methods similar to those used for calculating the benefits of structural projects, including similar treatment in calculating the benefits from losses avoided.

(2)

Avoidance of double counting

In carrying out paragraph (1), the Secretary should avoid double counting of benefits.

(c)

Counties substantially located within 100-year flood plain

For the purposes of subsection (a), a county is substantially located within the 100-year flood plain—
(1)
if the county is comprised of lands of which 50 percent or more are located in the 100-year flood plain; and
(2)
if the Secretary determines that application of the requirement contained in subsection (a)(1)(A) with respect to the county would unreasonably restrain continued economic development or unreasonably limit the availability of needed flood control measures.
(d)

Cost sharing

42 U.S.C. 4001Not later than , the Secretary shall transmit to Congress a report on the feasibility and advisability of increasing the non-Federal share of costs for new projects in areas where new or substantially improved structures and other constrictions are built or placed in the 100-year flood plain or the 10-year flood plain, as the case may be, after the initial date of the affected governmental unit’s entry into the regular program of the national flood insurance program of the National Flood Insurance Act of 1968 [ et seq.].

(e)

Regulations

Not later than 6 months after the date on which a report is transmitted to Congress under subsection (c), the Secretary, in consultation with the Director of the Federal Emergency Management Agency, shall issue regulations to implement subsection (a). Such regulations shall define key terms, such as new or substantially improved structure, constriction, 10-year flood plain, and 100-year flood plain.

(f)

Applicability

The provisions of this section shall not apply to any project, or separable element thereof, for which a final report of the Chief of Engineers has been forwarded to the Secretary before the last day of the 6-month period beginning on the date on which regulations are issued pursuant to subsection (a) but not later than .

Pub. L. 101–640, title III, § 308104 Stat. 4638Pub. L. 106–53, title II, § 219(a)113 Stat. 294(, , ; , , .)

Editorial Notes

References in Text

Pub. L. 90–44882 Stat. 572section 4001 of Title 42The National Flood Insurance Act of 1968, referred to in subsec. (d), is title XIII of , , , which is classified principally to chapter 50 (§ 4001 et seq.) of Title 42, The Public Health and Welfare. For complete classification of this Act to the Code, see Short Title note set out under and Tables.

Codification

Section was enacted as part of the Water Resources Development Act of 1990, and not as part of the Water Resources Development Act of 1986 which comprises this chapter.

Amendments

Pub. L. 106–53, § 219(a)(1)1999—Subsec. (a). , inserted “Exclusion of elements from” before “benefit-cost” in heading.

Pub. L. 106–53, § 219(a)(2)Subsecs. (b) to (d). , (3), added subsec. (b) and redesignated former subsecs. (b) and (c) as (c) and (d), respectively. Former subsec. (d) redesignated (e).

Pub. L. 106–53, § 219(a)(2)Subsec. (e). , (4), redesignated subsec. (d) as (e) and substituted “subsection (c)” for “subsection (b)”. Former subsec. (e) redesignated (f).

Pub. L. 106–53, § 219(a)(2)Subsec. (f). , redesignated subsec. (e) as (f).

Statutory Notes and Related Subsidiaries

Change of Name

section 612(c) of Pub. L. 109–295section 313 of Title 6References to the Director of the Federal Emergency Management Agency to be considered to refer and apply to the Administrator of the Federal Emergency Management Agency, see , set out as a note under , Domestic Security.

Transfer of Functions

section 315(a)(1) of Title 6For transfer of all functions, personnel, assets, components, authorities, grant programs, and liabilities of the Federal Emergency Management Agency, including the functions of the Under Secretary for Federal Emergency Management relating thereto, to the Federal Emergency Management Agency, see , Domestic Security.

section 542 of Title 6For transfer of functions, personnel, assets, and liabilities of the Federal Emergency Management Agency, including the functions of the Director of the Federal Emergency Management Agency relating thereto, to the Secretary of Homeland Security, and for treatment of related references, see former section 313(1) and sections 551(d), 552(d), and 557 of Title 6, Domestic Security, and the Department of Homeland Security Reorganization Plan of , as modified, set out as a note under .

Reevaluation of Flood Control Projects

Pub. L. 106–53, title II, § 219(b)113 Stat. 295

“At the request of a non-Federal interest for a flood control project, the Secretary shall conduct a reevaluation of a project authorized before the date of enactment of this Act [] to consider nonstructural alternatives in light of the amendments made by subsection (a) [amending this section].”
, , , provided that:

“Secretary” Defined

section 2 of Pub. L. 101–640section 2201 of this titleSecretary means the Secretary of the Army, see , set out as a note under .