[Federal Register Volume 74, Number 78 (Friday, April 24, 2009)]
[Notices]
[Pages 18745-18746]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-9322]


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INTERNATIONAL BOUNDARY AND WATER COMMISSION, UNITED STATES AND MEXICO, 
UNITED STATES SECTION


Notice of Availability of a Draft Environmental Assessment and 
Draft Finding of No Significant Impact for Flood Control Improvements 
to the Arroyo Colorado Floodway

AGENCY: United States Section, International Boundary and Water 
Commission, United States and Mexico.

ACTION: Notice of Availability of Draft Environmental Assessment (EA) 
and Draft Finding of No Significant Impact (FONSI).

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[[Page 18746]]

SUMMARY: Pursuant to Section 102(2)(c) of the National Environmental 
Policy Act (NEPA) of 1969 (42 U.S.C. 4321 et seq.), the Council on 
Environmental Quality Final Regulations (40 CFR Parts 1500 through 
1508), and the United States Section, International Boundary and Water 
Commission's (USIBWC) Operational Procedures for Implementing Section 
102 of NEPA, published in the Federal Register September 2, 1981 (46 FR 
44083); the USIBWC hereby gives notice of availability of the Draft 
Environmental Assessment and Draft FONSI for Flood Control Improvements 
to the Arroyo Colorado Floodway, which is part of the interior 
floodways in the Lower Rio Grande Flood Control Project.

FOR FURTHER INFORMATION CONTACT: Rita Crites, Environmental Protection 
Specialist, Environmental Management Division, United States Section, 
International Boundary and Water Commission; 4171 N. Mesa, C-100; El 
Paso, Texas 79902. Telephone: (915) 832-4781; e-mail: 
[email protected].

DATES: The Draft EA and Draft FONSI will be available April 27, 2009.

SUPPLEMENTARY INFORMATION: 

Background

    The Arroyo Colorado is an ancient distributary of the Rio Grande, 
and it serves as drainage for crop irrigation, municipal wastewater 
returns, and as a floodway during periods of heavy precipitation in the 
Lower Rio Grande Valley. The project area includes 2.1 miles of the 
Divisor Dike, and approximately 8.4 miles of the Arroyo Colorado north 
levee.
    The USIBWC prepared this EA for the proposed action to increase 
flood containment capacity of the Arroyo Colorado Levee System by 
raising the elevation of this segment for improved flood protection. 
This action will also address the 100-year flood protection criteria 
established by the Federal Emergency Management Agency (FEMA).
    The beginning of this project is at the Divisor Dike near the 
juncture point of the Arroyo Colorado and the North Floodway in Hidalgo 
County and the ending is at White Ranch Road in Cameron County, Texas.
    The proposed levee rehabilitation improvements consist of: (1) 
Raising the top-of-levee elevation, (2) conducting geotechnical 
investigations and testing to determine the type and extent of any 
required remediation improvements due to slope stability, seepage, 
levee settlement, and any other geotechnical issues that may cause 
levee failure during a 100-year flood event and (3) modifying, if 
necessary, hardware or structures located along the levee reaches. Any 
modifications will be in compliance with the Texas Historical 
Commission recommendations. The top elevation of the levee-raising 
improvements will be to provide containment of flood flows with a 
minimum freeboard of 3 feet for water surface elevations as calculated 
in the USIBWC 2003 Hydraulic Model for the LRGFCP. Raising on the 
riverside of the levee will be the most probable alternative given the 
nature of the right-of-way in the area.

Alternatives

    The USIBWC completed an EA of the potential environmental 
consequences of raising the Arroyo Colorado Floodway to meet current 
requirements for flood control. The EA, which supports the Finding of 
No Significant Impact, evaluated the Proposed Action and No Action 
Alternative.

Availability

    Single hard copies of the Final Environmental Assessment and Final 
Finding of No Significant Impact may be obtained by request at the 
above address. Electronic copies may also be obtained from the USIBWC 
Home Page at http://www.ibwc.gov/home.html.

    Dated: April 17, 2009.
Robert McCarthy,
General Counsel.
[FR Doc. E9-9322 Filed 4-23-09; 8:45 am]
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