United States Section; Intent To Prepare an Environmental Impact Statement for the Lower Colorado River Boundary and Capacity Preservation Project, Yuma County, AZ

The USIBWC proposes to gather information necessary for the preparation of an EIS to be used to determine specific options for the preservation of the boundary and channel and carrying capacity, and maintenance activities by the Lower Colorado River Boundary and Capacity Preservation Project (LCRBCPP) that could be implemented. Implementation would be conducted in a manner to minimize, consistent with the law and international agreements, the impact of the activities of the project on ecological and environmental resources in the project area. The project area is the 23.7 mile (38.2 kilometer (km)) boundary segment of the Lower Colorado River from the Northerly International Boundary (NIB) to the Southerly

International Boundary (SIB) river reach bounded by the levees in Arizona and Baja California Norte, Mexico. The EIS will discuss separately, among other laws and regulations, the requirements of international agreements with Mexico regarding the preservation of the boundary and channel and carrying capacity, and maintenance activities considered for the project, the Endangered Species Act, the Clean Water Act, the National Historic Preservation Act and others, as appropriate. Studies will include an analysis of impacts of alternatives for preservation of the boundary and channel and carrying capacity, and maintenance activities in relation to baseline flood flow design capacity, floodplain and channel maintenance, changes in the international boundary channel since 1972, and effects from upstream sediment input. Alternatives could include channel excavation/dredging, channel realignment, and levee improvements, or a combination of these alternatives. The alternatives are influenced to varying degrees by obligations and rights reserved by the governments of the United States and Mexico in the Treaty for ``Utilization of Waters of the Colorado and Tijuana Rivers and of the Rio Grande'' signed on February 3, 1944 (1944 Water Treaty), the ``Treaty to Resolve Pending Boundary Differences and Maintain the Rio Grande and Colorado Rivers as the International Boundary Between the United States of America and Mexico'' dated November 23, 1970, and international agreements concluded thereunder as International Boundary and Water Commission, United States and Mexico (IBWC) Minutes. The EIS will address impacts in the United States of activities in the United States related to alternatives for a long term boundary preservation and carrying capacity improvement project, the LCRBCPP, which is under consideration by the United States and Mexico for the project reach. None of these conditions can be dealt with effectively as a single issue or proposed project. The land and works located between the international boundary and the inside toe of the United States levee are owned, controlled and managed through several arrangements of a domestic, Federal and international nature. A range of options for the domestic and international activities encompassed in the study area of the Colorado River channel and floodway in the United States that could be implemented by the USIBWC will be considered. Operations and maintenance, in part, of the LCRBCPP fall within the realm of the international agreements governing the project and are therefore not a subject of the EIS. The USIBWC does not have unilateral control of all of the LCRBCPP and thus cannot make commitments which are international and controlled by the IBWC. The international and domestic activities are noted as follows. Morelos Dam, located 1.1 miles (1.8 km) downstream of NIB, is an international gated structure and weir spanning from levee to levee in the channel and floodplain used for a variety of requirements and agreements. The Colorado River clearing program is an international program and involves bank clearing to facilitate passage of the design flow of 140,000 cubic feet per second (3,960 cubic meters per second). Carrying capacity improvements is an emergency international program to assure deliveries of water to Mexico and consists of sediment removal. The hydrography program is an international program consisting of operations and maintenance of gaging stations. The boundary preservation program is an international floodplain management program designed to preserve and maintain the channel as the international boundary. United States floodplain features include incidental water systems consisting of a levee, bypass channel, and adjacent lands. Other features include the river floodplain consisting of access roads, water conveyance system components, farmlands, and vegetation in various stages of disturbance. The main channel is a United States floodplain feature which, upstream of Morelos Dam, carries flows which are allocated to Mexico by the 1944 Water Treaty, along with occasional high flows. Downstream of Morelos Dam, the channel carries only surface water from leakage from Morelos Dam and occasional high flows. There is more stream vegetation in the first 5.5 miles (8.9 km) below Morelos Dam than in the downstream portion to the SIB. The EIS will identify, describe, and evaluate the existing environmental, cultural, hydrological, socioeconomic and recreational resources; describe products for boundary mandates; explain channel carrying capacity, levee improvements and floodplain maintenance; and evaluate impacts associated with the alternatives under consideration. Significant issues which have been identified to be addressed in the EIS include, but are not limited to, affects on: (a) fish and wildlife; (b) endangered species; (c) terrestrial and aquatic habitats; (d) cultural resources; (e) river channel capacity; (f) international boundary alignment; and (g) water quality. External coordination will be conducted to include the United States Fish and Wildlife Service to insure compliance with section 7 of the Endangered Species Act of 1973, as amended, and the Fish and Wildlife Coordination Act. Cultural resources reconnaissance of the project area will be coordinated with the Arizona State Historic Preservation Officer. Coordination for the Clean Water Act will also be conducted, with the appropriate authorities. The environmental review of this project will be conducted in accordance with the requirements of NEPA, CEQ Regulations (40 CFR Parts 1500-1508), other appropriate federal regulations, and the USIBWC procedures for compliance with those regulations. Copies of the EIS will be transmitted to federal and state agencies and other interested parties for comments and will be filed with the Environmental Protection Agency in accordance with 40 CFR Parts 1500-1508 and USIBWC procedures. The USIBWC anticipates the Draft EIS will be made available to the public by approximately January, 2001.

Dated: May 14, 1999. William A. Wilcox, Jr., Legal Advisor. [FR Doc. 99-12836 Filed 5-20-99; 8:45 am] BILLING CODE 7010-01-U