MARITIME CHALLENGESDecrease in Rainfall in Central America Could Cut Off the Panama Canal

By Dirk Kaufmann

Published 30 May 2023

To see the economic consequences of global warming look no further than the Panama Canal. There, water levels are down because of less rain in Central America. Experts fear ordinary consumers may end up paying the price.

The Panama Canal connects the Atlantic Ocean with the Pacific. Its creation was a huge boon for global shipping. Before the canal was completed, a ship had to travel around the southern tip of South America, a much longer and more dangerous route.

The sea around the stormy Cape Horn was a veritable ships’ graveyard for centuries. Thousands of sailors died there and countless ships were lost. But the passage through the Panama Canal shortened the trip by more than 13,000 kilometers (8,000 miles), saving money and time.

But now, climate change appears to be threatening this route. Every time the canal’s locks are opened, millions of liters of fresh water flow into the sea. As a consequence, the water level in the canal drops. It is eventually replaced by more water flowing in. However now residents, conservationists and meteorologists are all observing a decrease in rainfall in Central America as a result of climate change. Which means less water for the canal. And if the fresh water that flows out of the canal’s locks can no longer be replaced, then large ships will find it increasingly difficult to pass through.

Where Does All the Water Come From?
The Panama Canal uses so much fresh water because ships have to go through a dozen locks that take them up or down 26 meters (85 feet). According to the consulting firm Everstream, which monitors and evaluates supply chains on behalf of international firms, around 200 million liters of water are needed for every ship passage through the canal.

The Panama Canal Authority, which is responsible for the operation of the canal, has issued strict draft restrictions in recent months. The draft of a ship is the distance between the waterline and the bottom of the ship. This measurement determines how much water a ship needs to safely navigate. If a ship is loaded with heavy goods, it sinks deeper creating a greater draft.  

Normal operating draft for the canal is 15.24 meters. At the start of May, authorities put out an draft adjustment advisory for the Neo-Panamax locks — the term refers to size limits of some of the largest ships going through the canal — based on projected water levels. Starting May 24, the largest ships that transit the canal will be limited to drafts of up to 13.56 meters. A week later on May 30, that will be reduced again to 13.4 meters.