Caracas, Venezuela ? Venezuela is at risk of a devastating power collapse as drought pushes water levels precariously low in the country’s biggest hydroelectric dam, posing a serious political threat for President Hugo Chavez.

Chavez on Friday said his government is determined to keep Guri Dam from falling to a critical level where the turbines start to fail in the next several months. He has also imposed rationing measures that include penalty fees for energy overuse, shorter workdays for many public employees and reduced hours for shopping malls.

The entire South American country of 28 million people depends to a large degree on the massive Guri Dam, which holds back the Caroni River in southeastern Bolivar state. It supplies 73 percent of the country’s electricity by feeding the massive Guri hydroelectric plant — the world’s third-largest in power output — along with two other smaller plants.

Chavez said that the dam’s water level is now about 33 feet below where it was last year, and if it falls 82 feet more before the dry season ends, “we would be at a standstill.”