U.S. flag

미국 정부 공식 웹사이트입니다

Dot gov

Official websites use .gov

A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS

A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites..

alert - warning

이 페이지는한국어로(으로) 번역되지 않았습니다. 해당 언어의 리소스는 한국어 페이지를 방문해 주십시오.

Alteration of a Watercourse

Alterations are often made to the channels of rivers, stream, or drainageways, usually to improve drainage, relocate the channel, or to increase its flood carrying capacity. There are two requirements for maintaining the flood carrying capacity of an altered watercourse. The altered or relocated watercourse must have the same or greater capacity as the original watercourse. Additionally, once the alteration is made, the capacity of the altered or relocated watercourse must be maintained over time.

If a development permit application proposes a stream alteration, the local official must notify adjacent communities, the State Coordinating Agency for the National Flood Insurance Program (NFIP), and provide a copy to the FEMA Regional Office. If an adverse impact is suspected, the neighboring community will be able to voice its concerns prior to any modification. Federal and state permits will usually be required for any alteration or relocation. It is recommended that the community require the submittal and approval of a Conditional Letter of Map Revision (CLOMR) for large-scale proposals. This assures that FEMA will recognize the project for a map change when construction is completed.

National Flood Insurance Program Requirements

  • 60.3 - Flood plain management criteria for flood-prone areas
    • (b) (6) - Notification Requirement
    • (b) (7) - Maintenance of flood carrying capacity