The Panama Canal Authority closed the canal around noon Wednesday after heavy rain in the Chagres River area caused water behind the Gatun Dam to rise. The dam creates Lake Gatun, a significant part of the canal.
When the canal reopened early Thursday morning 12 vessels that had been held up by the closing entered the canal and were able to complete their transits. The canal authority said the canal is now in full normal operations.
During the rainy season from May through December, torrential rains often cause the Chagres River to rise as much as 14 feet in one day.
Recent rains have caused havoc in nearby Venezuela and Colombia, and the authority said rainfall had pushed surrounding rivers and reservoirs to historically high levels, which could affect ships in transit.
Between 13,000 and 14,000 ships pass through the canal every year, about 36 per day, representing roughly 5 percent of world trade, according to the canal authority.
The last time the canal closed was in 1989 after the United States invaded Panama to topple strongman Manuel Noriega. Landslides forced the canal to close for several months from late 1915 to mid-1916, just months after it opened.