Under the terms of the 1944 Treaty relating to the Tijuana River, the IBWC in 1967 (IBWC Minute 225 of June 19, 1967) recommended to the two Governments and they approved a joint project for the control of floods on the Tijuana River in the United States and Mexico for protection of developments near the boundary in the City of San Diego, California and in the City of Tijuana, Baja California. A joint project was essential because coordinated flood control works were required in each country to protect developments in the other country. That project provided for 2.7 miles (4.3 kilometers) of a concrete-lined channel south of the boundary in Tijuana, veering westerwardly to then continue for 6 miles (9.7 kilometers) to the Pacific Ocean. The part of the project in the United States was modified in 1977 to the present stilling basin configuration (IBWC Minute 258) to conform to a change in land use planning in San Diego.

The Project

The project consists of concrete-lined channel for the Tijuana River in Mexico extending from the boundary upstream 2.7 miles (4 km), and of a concrete and rock-lined channel in the United States extending from the boundary downstream 0.9 miles (2 km). The downstream portion of the channel in the United States is a flared section to reduce the velocity of flows before discharging into the natural channel below the project. The channel and bordering levees were constructed pursuant to jointly approved design criteria and plans to contain a flood of 135,000 cfs (3,823 cms). The levees in the United State tie into high ground on the north to protect the community of San Ysidro and on the south to protect the City of Tijuana. Each Government constructed and maintains at its cost the part of the project in its territory under the supervision of the IBWC.

For the United States part of the project the State of California and the City of San Diego acquired and furnished the rights-of-way for the channel and the levees. The United States Section contracted with the United States Army Corps of Engineers, Los Angeles district, to prepare the plans and supervise the construction of the United States part.

In 1980 the project safely carried through its structures the highest flood flows in the Tijuana River since at least 1916, averting within the limits of the project property damage and probably life in the United States and Mexico.

Authority

The United States Section was authorized to construct its portion of the international flood control project by the Act of Congress of October 10, 1966, as amended by the Act of Congress of September 28, 1976. The latter was necessary to allow the United States Section to purchase the land needed for the smaller project. The project was completed in early 1979.

Tijuana River Basin

The Tijuana River drains a 1,730 square mile (4,480 km) basin situated partly in the United States and partly in Mexico. Originating in Mexico, the river crosses the international boundary into the United States near San Ysidro, California, then flows westerly in a broad flood plain about 5.3 miles (9 km) to discharge into the Pacific Ocean at a point about 1.5 miles (2 km) north of the boundary.