[Federal Register Volume 59, Number 41 (Wednesday, March 2, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-4683]


[[Page Unknown]]

[Federal Register: March 2, 1994]


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INTERNATIONAL BOUNDARY AND WATER COMMISSION

 

United States--Mexico Joint Project for Immediate Emergency 
Removal of Sediment in the Lower Colorado River in Mexico, Morelos Dam 
to the Northerly International Boundary--Finding of No Significant 
Impact

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

action: Notice of Finding of No Significant Impact.

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summary: Based on a revised draft environmental assessment, the United 
States Section of the International Boundary and Water Commission, 
United States and Mexico (USIBWC), finds that the proposed action that 
the United States Government and the Government of Mexico engage in a 
joint project for immediate emergency removal of sediment in the lower 
Colorado River in Mexico from Morelos Dam to the Northerly 
International Boundary (NIB) is not a major federal action that would 
have a significant adverse effect on the quality of the human 
environment. Therefore, pursuant to section 102(2)(C) of the National 
Environmental Policy Act of 1969; the Council on Environmental Quality 
Final Regulations (40 CFR parts 1500 through 1508); and the USIBWC's 
Operational Procedures for Implementing Section 102 of NEPA, published 
in the Federal Register September 2, 1981 (46 FR 44083-44094); the 
USIBWC hereby gives notice that an environmental impact statement will 
not be prepared for the proposed project.

addresses: Mr. M.R. Ybarra, United States Section Secretary; United 
States Section, International Boundary and Water Commission, United 
States and Mexico, 4171 North Mesa Street, C-310, El Paso, Texas 79902. 
Telephone: 915/534-6698.

SUPPLEMENTARY INFORMATION:

Proposed Action

    The action proposed is for the United States Government and the 
Government of Mexico to engage in a joint project to remove sediment in 
the lower Colorado River in Mexico from Morelos Dam to the Northerly 
International Boundary (NIB).
    The need for the project arises from extraordinary winter storm 
runoff in 1993 in the Gila River basin which resulted in the filling 
and spilling of Painted Rock Dam, located some 116 miles (187 
kilometers) upstream of the Gila River's confluence with the Colorado 
River. The sustained high flows carried a large sediment load, causing 
dangerous accumulations in the international boundary segment of the 
Colorado River.
    The sediment removal is necessary to provide immediate flood 
control relief in the vicinity of Morelos Dam and to enable Mexico to 
receive full deliveries of their 1944 Treaty waters. All sediment 
removal activities will be conducted in Mexico.

Alternatives Considered

    Three alternatives, including the No Action Alternative and the 
Proposed Action Alternative, were considered:
    The No Action Alternative would result in accumulated sediment not 
being removed from the lower Colorado River in the vicinity of Morelos 
Dam. Mexico would not be able to divert full domestic and irrigation 
allotments. Serious impacts to human health could result from an 
absence of an adequate domestic water supply. Sediment accumulation in 
the Morelos Dam system would increase flood stage elevations. The 
United States would not be acting in furtherance of the 1944 Water 
Treaty requirement to recommend and carry out flood control activities 
and the 1970 Boundary Treaty requirements for boundary preservation.
    The Proposed Action Alternative is a joint United States/Mexico 
emergency project to remove sediment upstream of the Morelos Dam flood 
control gates for a distance yet to be determined, but no further 
upstream than the NIB, and downstream of the Morelos Dam intake gates. 
The IBWC, on behalf of the United States and Mexico, would coordinate 
the work utilizing, as authorized in the 1944 Water Treaty, the 
resources of the U.S. Department of Interior, Bureau of Reclamation 
(Reclamation), and the Mexican National Water Commission.
    The project includes the removal of an estimated minimum 183,000 
cubic yards (140,000 cubic meters) of sediment downstream of the 
Morelos Dam intake structure in Mexico, assigned to Mexico, and removal 
of an estimated minimum 314,000 cubic yards (240,000 cubic meters) of 
sediment, assigned to the United States, immediately upstream of 
Morelos Dam in the Colorado River, also in Mexico, up to the NIB. The 
Mexican government has requested the United States government perform 
the part of the work assigned to Mexico at full reimbursement to the 
United States Government because the existing Mexican equipment does 
not have the capacity to remove the amount of sediment necessary to 
restore the intake canal capacity to 5,650 cubic feet per second (160 
cubic meters per second).
    Work will be performed utilizing dredging equipment. It may also be 
necessary to use earth moving equipment along the Mexican bank of the 
Colorado River. The spoil material will be temporarily placed in Mexico 
just upstream of Morelos Dam. Mexico will remove the spoil material to 
a permanent disposal site in Mexico in the near future. The United 
States will advise Mexico on disposal site preparation in that country. 
The sediment has been tested for the presence of pesticides and heavy 
metals. The result of the tests will be furnished to the interested 
resource agencies when they become available.
    This alternative will improve the flood carrying capacity in the 
Colorado River to pass flood flows through the NIB similar to those 
experienced during the 1993 Gila River floods. The Morelos Dam system 
will also allow Mexico to fully divert the waters delivered by the 
United States under the 1944 Water Treaty along with small flood flows 
that may arrive at the NIB. The United States would be acting in 
furtherance of the 1944 Water Treaty requirement to recommend and carry 
out flood control activities and the 1970 Boundary Treaty requirements 
for boundary preservation.
    The Sediment Removal and Flood Control Alternative would result in 
the United States and Mexico concluding an international agreement 
through a Minute of the IBWC for sediment removal in the Colorado River 
from the confluence of the Gila River to the lower end of the Mexicali 
Valley Irrigation District, including the Morelos Dam intake canal. 
This action would restore the carrying capacity of the river channel to 
about 25,000 cubic feet per second (708 cubic meters per second) to 
permit passage of the 100-year flood discharge of approximately 40,000 
cubic feet per second (1,130 cubic meters per second) with overbank 
discharges that will not overtop or endanger flood control levees in 
either the United States or in Mexico. This activity would also improve 
the Colorado River channel gradient in the lower end of the Mexicali 
Valley Irrigation District to increase the velocity of flood flows into 
the Laguna Salada diversion channel and to the Gulf of California. This 
alternative would also allow the United States and Mexico to resolve 
existing boundary issues and other differences in a cooperative manner.
    This alternative would be a major federal undertaking which could 
not be accomplished within the short time needed to correct water 
diversion problems or handle potential significant flood events during 
1994. An undertaking of this magnitude would also involve a 
consideration of river stabilization and river rectifications in 
addition to sediment removal. Such activities would require extensive 
cost-benefit analysis and environmental impact evaluation. This 
alternative was therefore not given further consideration. Instead, the 
elements of this alternative were considered as elements that merit 
considerable binational study for a possible longer term activity.

Revised Draft Environmental Assessment

    The USIBWC met with the interested resource agencies on February 
15, 1994, in Yuma, Arizona, to discuss the proposed action. The Revised 
Draft Environmental Assessment (RDEA) for the proposed project was 
completed on February 16, 1994, and made available for review and 
comment.
    On the basis of the consensus reached with the interested resource 
agencies and the RDEA, the USIBWC has determined that an environmental 
impact statement is not required for the United States Government and 
the Government of Mexico to engage in a joint project for immediate 
emergency removal of sediment in Mexico from Morelos Dam to the NIB and 
hereby provides notice of a finding of no significant impact.
    An environmental impact statement will not be prepared unless 
additional information which may affect this decision is brought to our 
attention within thirty (30) days of the date of this Notice.
    The RDEA and Draft Finding of No Significant Impact (FONSI) have 
been forwarded to the Environmental Protection Agency and various 
Federal, State, and local agencies and interested parties. A limited 
number of copies of these documents are available to fill single copy 
requests at the above address.

    Dated: February 23, 1994.
Manuel R. Ybarra,
Secretary.
[FR Doc. 94-4683 Filed 3-1-94; 8:45 am]
BILLING CODE 4710-03-M