---
kind: "section"
citation: "43 U.S.C. § 1600c"
title: "43"
title_heading: "Public Lands"
number: "1600c"
heading: "Colorado River Floodway"
release: "119-102"
date: "2026-07-12"
url: "https://uscodex.org/usc/43/1600c"
units:
  - "Chapter 32B — Colorado River Floodway"
---

# §1600c. Colorado River Floodway

- (a) **Establishment—** There is established the Colorado River [Floodway](/usc/43/1600a.md?p=e) as identified and generally depicted on maps that are to be submitted by the [Secretary](/usc/43/1600a.md?p=c).
- (b) **Study of tributary floodflows; determination of Floodway boundary—** Within eighteen months after October 8, 1986, the [Secretary](/usc/43/1600a.md?p=c), in consultation with the seven Colorado River Basin [States](/usc/43/31b.md?p=8), represented by persons designated by the Governors of those [States](/usc/43/31b.md?p=8), the Colorado River [Floodway](/usc/43/1600a.md?p=e) 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](/usc/43/1600a.md?p=e) so that the [Floodway](/usc/43/1600a.md?p=e) 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](/usc/43/1600a.md?p=c) shall conduct, at least once every five years, a review of the Colorado River [Floodway](/usc/43/1600a.md?p=e) and make, after notice to and in consultation with appropriate chief executive officers of [States](/usc/43/31b.md?p=8), counties, municipalities, [water districts](/usc/43/1600a.md?p=d), Indian tribes, or equivalent jurisdictions in which the [Floodway](/usc/43/1600a.md?p=e) is located, and others, such minor and technical modifications to the boundaries of the [Floodway](/usc/43/1600a.md?p=e) 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](/usc/43/1600e.md).
  - (2) If, in the case of any minor and technical modification to the boundaries of the [Floodway](/usc/43/1600a.md?p=e) made under the authority of this subsection, an appropriate chief executive officer of a [State](/usc/43/31b.md?p=8), county, municipality, [water district](/usc/43/1600a.md?p=d), 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](/usc/43/1600a.md?p=c) makes a modification which is in conflict with such comments, the [Secretary](/usc/43/1600a.md?p=c) shall submit to the chief executive officer a written justification for his failure to make modifications consistent with such comments or proposals.

## Source credit

(Pub. L. 99–450, § 5, Oct. 8, 1986, 100 Stat. 1131; Pub. L. 105–362, title IX, § 901(d), Nov. 10, 1998, 112 Stat. 3289.)

## Notes

### 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,”.