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Western Land Boundary Project

San Diego Field Office

The San Diego Field office is a dual function office with both Construction and Operation and Maintenance assignments. The functions of the office are to carry out designated operations and maintenance functions which support the U.S. Section of the International Boundary and Water Commission which include:

  • To manage, plan, and administer the operation and maintenance program for the South Bay International Wastewater Treatment Plant (SBIWTP) and facilities, and the International Tijuana River Flood Control Project (ITRFCP). Performance of maintenance on levees, road, channel and flood way; administering the operation and maintenance of the river gage in the Tijuana River; and operation and accounting of flow through the Emergency Connection.
  • To manage, plan, and administer the utilization and maintenance of heavy and light equipment, vehicles, structures, communications systems, support fuels, supplies, and materials to assure the efficient and economical functioning of the Project.
  • The South Bay International Wastewater Treatment Plant (SBIWTP) is located on a 75-acre site near the international border and provides for advanced primary treatment of 25 mgd of Tijuana sewage. The SBIWTP construction was completed in September, 1997 and began full operation in January, 1999 upon completion of the South Bay Ocean Outfall.
  • The Tijuana Flood Control Channel began construction in late 1977, and is used to contain and convey Tijuana River flood flows up to 135,000 cubic feet per second in both the United States and Mexico. In the United States, the channel consists of a partial trapezoidal concrete lined channel, which expands to grouted stone, and then natural soil flood way.


South Bay IWTP Operational Approaches: Project Report for Full Scale Testing of TSS Removal Improvements

Yuma Field Office

Our Yuma office is located at 2995 S. Pacific Avenue, Suite A, Yuma, AZ 85365. The Colorado River, which runs from north to south, forms the international boundary between the United States and Mexico for 24 miles in the vicinity of Yuma, Arizona and San Luis Rio Colorado, Sonora. The 1944 Water Treaty between the two countries includes a requirement that the U.S. deliver to Mexico a specified quantity of water from the Colorado River every year. Ensuring delivery of this water is a key responsibility of the Yuma office.

The 1944 Water Treaty states that 1.5 million acre-feet of Colorado River water be allotted to Mexico annually with an additional 200,000 allotted during years of surplus. Water allotment reduced in the event of extraordinary drought or serious accident to the U.S. irrigation system. The main accounting station for the 1.5 million acre feet diverted at the Morelos Dam is the Northerly International Boundary (NIB) gaging station.

The treaty authorized the construction of the Morelos Dam to divert water for Mexican use as well as Davis Dam and Reservoirs to assist the U.S. in delivering water to Mexico. The treaty also authorizes construction of flood control works - structures are maintained by the Commission to this day.
Other Responsibilities include:

  • To manage, plan, and administer the operation and maintenance of an extensive system of river gages and facilities in the Colorado River and canal systems for the purpose of securing water accounting, water quality, and salinity data required to meet treaty and domestic requirements;
  • In coordination with Mexico, to assure the safe and proper operation and maintenance of a flood control system on the Colorado River and of the Morelos Diversion Dam in Mexico;
  • In coordination with counterpart representatives of the Mexican government, to monitor the water quality in the New River and in Mexicali, Baja California, Mexico, through observation and the collection of samples;
  • To monitor the condition of the Wellton-Mohawk Bypass Drain in Mexico, and to coordinate the maintenance of the system with the U.S. Bureau of Reclamation and Mexico;
  • To compute and verify water quantity and quality data in preparation for publication in the Western Boundary Water Bulletin; and
  • Collection of samples and calculation of monthly and annual salinity differentials between Imperial Dam in the United States and the Morelos Dam in Mexico to assure compliance with treaty requirements.
  • Hydrographic sites: Fourteen (14) locations with major function to collect data for water accounting per the 1944 Water Treaty. Other functions are to collect data stipulated in Minute 197/242 etc.
  • Staff: Six (5) FTE’s, currently. Area Operations Manager; Environmental Protection Assistant; Hydrologic Technician (OA) and three (2) Hydrologic Technicians.