The Antonio Lucchetti Dam is on the Rio Yauco, about 4.3 miles north of the town of Yauco, Puerto Rico. It was designed, built, and is being operated by the Puerto Rico Water Resources Authority as a unit of the Southwestern Puerto Rico Project. This project integrates six drainage basins by means of six diversion and storage dams and five tunnels. The project generates nearly 100 million kilowatt hours of hydroelectric energy annually, provides water for the irrigation of 26,000 acres in the Lajas valley and for the water supply of several towns, and furnishes a measure of flood protection for the region.
The dam is a concrete gravity structure, 175 feet in maximum height, 580 feet in length, 101,700 cubic yards in volume. It has a center spillway designed to accommodate a flood of 62,800 second feet. The dam was completed in May 1952. The site was investigated by the writer in 1950-1951 under a co-operative agreement between the Puerto Rico Water Resources authority and the U. S. Geological Survey.
Although the general location of the dam was controlled by the layout requirements of the entire project, the site was chosen to take advantage of a constriction of the valley below the confluence of the Rio Yauco and the Quebrada Grande. At the dam, the valley of the Rio Yauco is about 850 feet deep. The river is about 50 feet wide at the site and flows between steep valley sides. A vertical rock bluff about 100 feet