The Panama Canal Authority has announced that the maximum draft of ships would be cut from the existing limit of 39.5 feet (12.04 meters) to 39 feet (11.89 meters) beginning Sept. 8.

The move affect up to 20 percent of current traffic. The authorities have also warned that, should there be no improvement in the drought, the limit can be further reduced to 38.5 feet (11.73 meters) from Sept. 16., the Associated Press reported.

They added that the restriction is mainly because of the drought caused by El Nino, as it has lowered the water levels in Gatun and Alhajuela lakes.

The present cut is the first caused by weather in the last 20 years, as a similar restriction was imposed for the same reason in 1998.

Scientists have warned of the devastating effects of El Nino and its complex weather patterns resulting from variations in ocean temperatures in the Equatorial Pacific. Both droughts and flash flooding are among the most dangerous consequences. The rainfall over the watershed that feeds the waterways has dropped because of the change in weather patterns, according to The Guardian.

Panama Canal is one of the world's main trade routes and connects the Atlantic Ocean to the Pacific Ocean. The Panama Canal celebrated its centenary in 2014 and has seen over a million ships. Since it took control from the U.S. in 2000, the government receives approximately $1 billion a year as revenue through transit and other fees, BBC News reported.
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Each ship that transits through the canal requires about 52 million gallons of water, equivalent to nearly 82 Olympic sized swimming pools. according to The Guardian.

The cut does not surprise the big shippers, as they had been warned and were expecting this to happen. However, authorities said that only a few ships would be barred.

The Panama Canal Authority said that the cut could affect around one-fifth of the existing ship traffic that use the canal daily.