Chixoy River in the context of Usumacinta

The Chixoy-Polochic Fault, also known as Cuilco-Chixoy-Polochic Fault, is a major fault zone in Guatemala and southeast Mexico. It runs in a light arc from the east coast of Guatemala to Chiapas, following the deep valleys of the Polochic River, Chixoy River and Cuilco River.

The Usumacinta River (Spanish pronunciation: [usumaˈsinta]; named after the howler monkey) is a river in southeastern Mexico and northwestern Guatemala. It is formed by the junction of the Pasión River, which arises in the Sierra de Santa Cruz (in Guatemala) and the Salinas River, also known as the Rio Chixoy, or the Rio Negro, which descends from the Sierra Madre de Guatemala. It defines part of the border between Guatemala and the Mexican state of Chiapas, then continues its northwesterly course, meandering through the Mexican state of Tabasco to the Gulf of Mexico.

The Usumacinta River enters Mexican territory in the state of Tabasco and across the Cañón del Usumacinta (Usumacinta Canyon) ecological reserve, forming impressive canyons along its route. Passing the canyon called "Boca del Cerro", Tenosique, the Usumacinta goes into the plain of Tabasco.

The Salinas is a river in Guatemala. The river is called Río Negro from its sources (located at 15°16′13″N 91°24′49″W / 15.270358°N 91.413717°W / 15.270358; -91.413717 (Sources of the Río Negro)) in the highlands of Huehuetenango and El Quiché until it reaches the Chixoy hydroelectric dam (located at 15°16′54″N 90°29′27″W / 15.281536°N 90.490952°W / 15.281536; -90.490952 (Chixoy Hidroelectric Dam)), where the Río Salama and Rio Carchela converge with the Río Negro. After the Chixoy dam, the river is called Río Chixoy and flows northwards through Alta Verapaz until it reaches the border with Mexico. It continues along the border for 113 kilometres (70 mi) as the Salinas river until it finally converges with the Río de la Pasión (at 16°28′52″N 90°32′39″W / 16.481193°N 90.544167°W / 16.481193; -90.544167 (Convergence Salinas and Pasión rivers)) to form the Usumacinta river which flows into the Gulf of Mexico.

Guatemala's National Institute for Electricity (INDE) is planning the construction of a new hydroelectric dam on the Chixoy river. The proposed location of the Xalalá hydroelectric dam is situated at 15°41′34″N 90°47′11″W / 15.692833°N 90.786361°W / 15.692833; -90.786361 (Planned location Xalalá Hidroelectric Dam). in the municipality of Ixcán, El Quiché.

The Chixoy Dam (Spanish: Planta Hidroeléctrica Chixoy) is a reinforced concrete dam and power plant spanning the Chixoy River between the Departments of Baja Verapaz, El Quiché and Alta Verapaz, Guatemala. It is the largest structure of its kind in the country.

It was built between 1976 and 1985 and generates approximately 15% of the country's electricity.