Title 43, Public LandsRelease 119-110

§1600c Colorado River Floodway

Title 43 › CHAPTER 32B — COLORADO RIVER FLOODWAY › § 1600c

Last updated Sep 22, 2026|Official source

Summary

Creates the Colorado River Floodway and requires the Secretary to map it. Within eighteen months after October 8, 1986, the Secretary, working with the seven Colorado River Basin States (via governor-appointed reps), the Floodway Task Force, and other interested parties, must study tributary floodflows below Davis Dam and draw exact Floodway boundaries so the area can handle either a one-in-one-hundred-year flow or 40,000 cubic feet per second (cfs), whichever is greater, from below Davis Dam to the U.S.-Mexico border. The Secretary must review the Floodway at least once every five years, notify and consult with top officials of affected States, counties, cities, water districts, tribes, and others, and make only minor technical boundary changes needed because the floodplain moved naturally or as allowed by subsection (c) of section 1600e. If an official objects and the Secretary keeps a change anyway, the Secretary must send a written explanation of why the comments were not followed.

Full Legal Text

Title 43, §1600c

Public Lands, Source: USLM XML via OLRC

(a)Establishment
There is established the Colorado River Floodway as identified and generally depicted on maps that are to be submitted by the Secretary.
(b)Study of tributary floodflows; determination of Floodway boundary
Within eighteen months after October 8, 1986, the Secretary, in consultation with the seven Colorado River Basin States, represented by persons designated by the Governors of those States, the Colorado River Floodway Task Force, and any other interested parties shall:
(1)complete a study of the tributary floodflows downstream of Davis Dam;
(2)define the specific boundaries of the Colorado River Floodway so that the Floodway can accommodate either a one-in-one hundred year river flow consisting of controlled releases and tributary inflow, or a flow of forty thousand cubic feet per second (cfs), whichever is greater, from below Davis Dam to the Southerly International Boundary between the United States of America and the Republic of Mexico.
(c)Review and modification of boundaries; notice and comment; written justification for decision of Secretary
(1)The Secretary shall conduct, at least once every five years, a review of the Colorado River Floodway and make, after notice to and in consultation with appropriate chief executive officers of States, counties, municipalities, water districts, Indian tribes, or equivalent jurisdictions in which the Floodway is located, and others, such minor and technical modifications to the boundaries of the Floodway as are necessary solely to reflect changes that have occurred in the size or location of any portion of the floodplain as a result of natural forces, and as necessary pursuant to subsection (c) of section 1600e of this title.
(2)If, in the case of any minor and technical modification to the boundaries of the Floodway made under the authority of this subsection, an appropriate chief executive officer of a State, county, municipality, water district, Indian tribe, or equivalent jurisdiction, to which notice was given in accordance with this subsection files comments disagreeing with all or part of the modification and the Secretary makes a modification which is in conflict with such comments, the Secretary shall submit to the chief executive officer a written justification for his failure to make modifications consistent with such comments or proposals.

Legislative History

Notes & Related Subsidiaries

Editorial Notes

Amendments

1998—Subsec. (b). Pub. L. 105–362, § 901(d)(1), struck out par. (1) designation, redesignated cls. (i) and (ii) of former par. (1) as pars. (1) and (2), respectively, and struck out former pars. (2) and (3) which related to preparation and filing of maps with congressional committees, Federal, State, and local government agencies, and federally insured financial institutions. Subsec. (c)(1). Pub. L. 105–362, § 901(d)(2), substituted “appropriate chief executive officers of States, counties, municipalities, water districts, Indian tribes, or equivalent jurisdictions in which the Floodway is located,” for “the appropriate officers referred to in paragraph (3) of subsection (b) of this section,”.

Reference

Citations & Metadata

Citation

43 U.S.C. § 1600c

Title 43, Public Lands

Last Updated

Sep 22, 2026

Release point: 119-110