Drought behind Panama Canal’s 2023 shipping disruption ‘unlikely’ without El Niño

Ayesha Tandon

A lengthy drought that caused widespread disruption to commercial ships passing through the Panama Canal in 2023 would have been “unlikely” without the influence of El Niño, according to a rapid attribution study.

Last year was Panama’s third driest on record. The low rainfall caused water levels in Gatún Lake – a crucial part of the country’s internationally important canal and key fresh water supply for millions of people – to drop to record-low levels.

Authorities reduced shipping through the canal to conserve the lake’s fresh water, resulting in queues of ships waiting for weeks to cross the canal. As shipments of everything from fruit to gas were delayed and rerouted, knock-on effects rippled across the globe.

The new study, by the World Weather Attribution service, did not find a significant long-term drying trend in rainfall over Panama. However, it noted that since 1900, four of the five driest years in the region have occurred in El Niño years.

El Niño reduced last year’s rainfall by about 8%, the authors find.

With the canal’s water use expected to more than double by 2050, the study warns that authorities “may need to re-introduce shipping restrictions to safeguard drinking water supplies, particularly in El Niño years”.

§ Shipping backlog

Opened in 1914, the Panama Canal – an engineered waterway connecting the Pacific and Atlantic Oceans – is a cornerstone for global marine shipping. Around 14,000 ships pass through the canal every year, accounting for 5% of all global maritime trade.

Using the canal, rather than travelling around the southern tip of South America, ships can cut some 13,000km off their journey. Ships pay a toll for using the canal, which adds more than $2.5bn to Panama’s economy every year.

Gatún Lake is pivotal for the canal’s operation. This artificial, rain-fed lake sits near the centre of the canal, around 26 metres above sea level. Ships travelling into the canal pass through a series of locks, each of which fills with water to raise the ship up to the level of the lake. After travelling through the lake, another series of locks lower the ships back down to sea level.

For every ship that moves through the canal – a process which takes between eight and 10 hours – around 200m litres of fresh lake water is used, most of which is flushed out to sea. 

Panama is the fifth wettest country in the world and sees most of its rainfall in its May-December rainy season.

However, total rainfall in 2023 was 30% lower than average. October was especially dry, recording 41% less rainfall than usual.

As a result, water levels in the rainfall-fed Gatún Lake reached a record low in the second half of 2023.

The map below shows water levels in Gatún Lake since 1965, where each line represents one year. The solid black line indicates 2023-24, while the dashed line shows projected lake water levels until mid-June 2024.

Image - Water levels in Gatún Lake since 1965. Source: WWA (2024) - Water levels in Gatún Lake since 1965. (note)

Under normal circumstances, the Panama Canal allows 36 “transits” every day. However, as lake levels dropped, the Panama Canal Authority (APC) began taking measures to conserve water. It reduced the number of daily crossings first to 32, then 31. And finally in November 2023 it announced that only 25 crossings would be allowed per day. 

Ships began waiting in line for weeks to cross the canal, often paying millions of dollars to jump the queue if another ship with a booked reservation dropped out. By late August, around 135 ships were waiting to cross – 50% more than normal. 

Around the world, shipments of everything from food to fuel were delayed

§ Compounding impacts

The Panama drought shows how changes in weather conditions, such as rainfall patterns, can interact with other hazards. 

Maja Vahlberg is a risk consultant at the Red Cross Red Crescent Climate Centre and author on the study. She told the press briefing that disruptions to the Panama Canal interacted with those in the Suez Canal – caused by Yemen’s Houthi group attacking commercial ships in the Red Sea – to drive “compounding and cascading impacts” on global shipping patterns.

This also exacerbated the existing disruptions caused by Russia’s invasion of Ukraine and the Covid pandemic

As a backlog of ships in the Panama Canal grew, delays lengthened from days to weeks. Al Jazeera described the affected shipments: 

“Bananas from Ecuador to Florida. Poultry from Chile to northern Europe. Liquid Natural Gas from the US to Asia. And virtually anything under the sun out of China.”

Around December, newspapers began to warn that shipments of Christmas goods may fail to reach retailers in time for the festive season.

Europe typically imports fresh produce from South and Central America during the winter months, with food and drink making up 77% of container shipments between the west coast of South America and Europe in 2022. 

For example, Peru supplies the UK with £2bn worth of goods every year, including more than £350m of “fresh produce”. However, many ships carrying fruits, vegetables and meat from South America to Europe were stuck in the backlog, resulting in “excessive delays”.

The drought also impacted shipments of oil and gas. The US uses the canal as a major trade route for carrying liquefied natural gas (LNG) from the Gulf coast to Asia. However, average waiting times for tankers carrying LNG north through the canal rose from eight days in July to 18 days in August.

Meanwhile, Gatún Lake also supplies drinking water for more than half of Panama’s 4.3 million people. As a result, the government was required to balance the demands of international shipping with the water usage needs of the locals.

Vahlberg told the press briefing that “Indigenous, Afro-Panamanian and some rural communities have very water-dependent livelihoods”. She explained that these communities often have “higher rates of poverty and limited access to basic services”, meaning that “even small changes in precipitation can bring disproportionate impacts on their livelihoods”.

She added that urban expansion and population growth, combined with ageing infrastructure that loses water through leaks, are putting increasing pressure on the country’s water supplies. 

The study notes that by 2050, the canal’s water use is expected to be more than double 2015 levels. It warns that, in future, authorities “may need to re-introduce shipping restrictions to safeguard drinking water supplies, particularly in El Niño years”.

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