[Federal Register Volume 72, Number 125 (Friday, June 29, 2007)]
[Notices]
[Pages 35721-35722]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-12509]



[[Page 35721]]

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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 Finding of No Significant Impact for 
Improvements to the Donna-Brownsville Levee System, in the Lower Rio 
Grande Flood Control Project, Hidalgo and Cameron Counties, Texas

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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SUMMARY: Pursuant to Section 102(2)(c) of the National Environmental 
Policy Act (NEPA) of 1969, 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 that the Draft Environmental Assessment and FONSI 
for Improvements to the Donna-Brownsville Levee System, in the Lower 
Rio Grande Flood Control Project, located in Hidalgo and Cameron 
Counties, Texas, are available. An environmental impact statement will 
not be prepared unless additional information which may affect this 
decision is brought to our attention within 30-days from the date of 
this Notice.

FOR FURTHER INFORMATION CONTACT: Daniel Borunda, 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) 832-4767; e-mail: 
[email protected].

DATES: Comments on the Draft EA and Draft FONSI will be accepted within 
30 days from the date of this Notice.

SUPPLEMENTARY INFORMATION:

Background

    The USIBWC is authorized to construct, operate, and maintain any 
project or works projected by the United States of America on the Lower 
Rio Grande Flood Control Project (LRGFCP), as authorized by the Act of 
the 74th Congress, Sess. I Ch. 561 (H.R. 6453), approved August 19, 
1935 (49 Stat. 660), and codified at 22 U.S.C. Section 277, 277a, 277b, 
277c, and Acts amendatory thereof and supplementary thereto.
    The LRGFCP was constructed to protect urban, suburban, and highly 
developed irrigated farmland along the Rio Grande delta in the United 
States and Mexico.
    The USIBWC, in cooperation with the U.S. Fish and Wildlife Service 
(USFWS), prepared this Draft Environmental Assessment (Draft EA) for 
the proposed action of raising the Donna-Brownsville Levee System 
located in Hidalgo and Cameron Counties, Texas to improve flood 
control. This levee system is part of the LRGFCP that extends 
approximately 180 miles from the Town of Pe[ntilde]itas in south Texas 
to the Gulf of Mexico. The Donna-Brownsville Levee extends 65 miles 
along the Rio Grande, downstream from the Donna Pump Station in Hidalgo 
County to an area east of Brownsville, approximately 28 miles upstream 
of the Gulf of Mexico, in Cameron County.

Proposed Action

    The Proposed Action would increase the flood containment capacity 
of the Donna-Brownsville Levee System by raising elevation of a number 
of levee segments to meet a 3-foot freeboard design criterion for flood 
protection. Height increases up to 2 feet are typically needed to reach 
the design freeboard value. The increase in levee height will result in 
an expansion to the levee footprint by lateral extension of the 
structure. Structural improvements may be required for some levee 
segments where seepage is a potential problem.

Alternatives to the Proposed Action

    A No Action Alternative was evaluated for the Donna-Brownsville 
Levee System. This alternative will retain the existing configuration 
of the system, as designed over 30 years ago, and the current level of 
protection currently associated with this system. Under severe storm 
events, current containment capacity may be insufficient to fully 
control Rio Grande flooding, with risks to personal safety and 
potential property damage.

Summary of Findings

    Pursuant to NEPA guidance (40 Code of Federal Regulations 1500-
1508), The President's Council on Environmental Quality issued 
regulations for NEPA implementation, which included provisions for both 
the content and procedural aspects of the required Environmental 
Assessment. The USIBWC completed an EA of the potential environmental 
consequences of raising the Donna-Brownsville Levee System to meet 
current requirements for flood control. The EA, which supports this 
Finding of No Significant Impact, evaluated the Proposed Action and No 
Action Alternative.

Levee System Evaluation

No Action Alternative

    The No Action Alternative was evaluated as the single alternative 
action to the Proposed Action. The No Action Alternative will retain 
the current configuration of the Donna-Brownsville Levee System, with 
no impacts to biological and cultural resources, land use, community 
resources, or environmental health issues. In terms of flood 
protection, however, current containment capacity under the No Action 
Alternative may be insufficient to fully control Rio Grande flooding 
under severe storm events, with associated risks to personal safety and 
property.

Proposed Action

Biological Resources
    Improvements to the Donna-Brownsville Levee System require 
excavation and fill activities that would affect plant communities 
within the expanded levee footprint area. Nearly all vegetation 
removal, 51.5 acres, would be limited to invasive-species grassland 
that is expected to be rapidly re-established. While approximately 17 
percent of the 65 mile levee system is adjacent to conservation areas, 
those non-native grasslands are located within the right-of-way (ROW) 
and have very limited value as wildlife habitat. No significant effects 
are anticipated for any of the 15 threatened and endangered species 
with potential habitat in the vicinity of the levee system. No wetlands 
are located within the potential levee expansion area.
Cultural Resources
    Improvements to the Donna-Brownsville Levee System may adversely 
affect known archaeological resources, by mechanical excavation or by 
burial under the expanded levee footprint. Resources potentially 
affected include eight areas that may contain historic or prehistoric 
archaeological materials, and one known archaeological site. Out of 65 
historic-age resources located in the levee system vicinity, twelve 
could be affected by the proposed levee improvements. Those historic-
age resources are mostly associated with irrigation structures and 
canals adjacent to the levee system.

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Water Resources
    Improvements to the levee system would increase flood containment 
capacity to control the design flood event with a negligible increase 
in water surface elevation. Levee footprint expansion would not affect 
water bodies.
Land Use
    The expansion would take place almost completely within the ROW and 
would not affect urban or agricultural lands. A minimum removal of 
woodland from natural resources management areas, less than 1 acre, 
would be required.
Community Resources
    In terms of socioeconomic resources, the influx of federal funds 
into Hidalgo and Cameron Counties from the levee improvement project 
would have a positive local economic impact limited to the construction 
period; the impact would represent less than 1 percent of the annual 
county employment, income and sales values. No adverse impacts to 
disproportionately high minority and low-income populations were 
identified for construction activities. Moderate utilization of public 
roads is required during construction; a temporary increase in access 
road use would be required for equipment mobilization to staging areas.
Environmental Health Issues
    Estimated air emissions of five criteria pollutants during 
construction represent from 0.06 percent to 1.64 percent of the Hidalgo 
and Cameron Counties annual emissions inventory. There would be a 
moderate increase in ambient noise levels due to excavation and fill 
activities. No long-term and regular exposure is expected above noise 
threshold values. A database search identified a number of waste 
storage or disposal sites in the levee system vicinity, all located 
within the City of Brownville. None of those sites would affect, or be 
affected, by the levee improvement project.
Best Management Practices and Mitigation
    Engineering design measures will be used, including optimization of 
the levee expansion alignment to avoid impacts on wooded vegetation, 
wetlands, and other natural resources. Best management practices during 
construction will include development of a storm water pollution 
prevention plan to avoid impacts to receiving waters, and use of 
sediment barriers and soil wetting to minimize erosion.
    To protect vegetation, the construction corridor may be re-
vegetated with herbaceous or woody vegetation, as agreed with the 
natural resources management organization where the levee expansion 
corridor is located. To protect wildlife, construction activities will 
be scheduled to occur, to the extent possible, outside the March to 
August bird migratory season.
    To avoid significant impacts on cultural resources, an additional 
survey of archaeological and historical resources will be conducted 
following completion of the engineering design phase, and mitigation 
actions will be adopted as recommended by the Texas Historical 
Commission (THC). Measures to avoid or minimize potential impacts to 
historical or archaeological resources will be specified in a 
Memorandum of Agreement between THC and the USIBWC.

Availability

    Single hard copies of the Draft Environmental Assessment and 
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.state.gov.

    Dated: June 25, 2007.
Susan Daniel,
General Counsel.
 [FR Doc. E7-12509 Filed 6-28-07; 8:45 am]
BILLING CODE 7010-01-P