The Panama Canal is one of the great engineering works of the 20th century. .

For over a century, the Panama Canal, one of the great works of Latin American engineering of the 20th century, has been the shortest route between the two largest oceans in the world.

Almost 6% of world trade passes through it: each year, more than 12,000 ships cross it from one side to the other to carry their goods or passengers on more than 140 routes to more than 160 countries.

But the artificial road between the Pacific and the Atlantic, opened in 1914, has suffered one of its worst natural crises since last year and has nothing to do with the efforts involved in keeping it running in times of coronavirus: it is running out of water.

As announced in early January by the Canal Authority (ACP), the public legal entity that administers it, the scarcity of rainfall in 2019 put in check the complicated mechanism of locks that moves ships between one sea and another.

The ACP indicated that during 2019 the area registered a reduction in 20% rainfall compared to the historical average, making it the fifth driest year in the past seven decades.

“We had an extremely dry year and this led us to implement various measures to guarantee the conservation of the water resource,” he explains to BBC Mundo. Carlos A. Vargas, Vice President of Water and Environment of the Panama Canal.

.Lreduction of precipitation has led the Canal authorities to take measures to control water consumption.

Since 2019, the canal authorities have cut the quota of boats that cross it every day as a measure to save water, while also reducing the draft of the ships that could cross it.

Since February, ships passing by sea must also pay for the fresh water they consume: a fixed rate that goes up to the $ 10,000 (and that depends on the size of the boat) plus another variable charge that takes into account the level of the lake that supplies it on the day of the crossing.

As confirmed by the ACP to BBC Mundo, by the beginning of May the strategy was working and the water level of the lake that allows the Canal to operate had led to the authorization of the passage of ships with a draft greater than that which had been anticipated.

However, as the rainy season is about to begin, Panamanian meteorologists still cannot agree on what to expect this year: whether the rains will make the task easier or whether the drought will do its thing again.

But how do you explain why a canal between two oceans runs out of water?

Canal Water

As Panamanian geographer and hydrologist Gustavo Cárdenas Castillero explains to BBC Mundo, among the many technical problems faced by the engineers who built the Canal at the beginning of the 20th century was the unevenness between the two oceans it connects.

“To solve this, a system of locks was created, to which fresh water coming from an artificial lake, the Gatún, is injected or extracted, which was created precisely as part of the strategy to overcome this gap between the terrain and the sea ”, he explains.

It was necessary to flood towns and bury mountains for the construction of the dam, which covers an area of ​​more than 430 km² and which also contributes to the supply of drinking water in much of the country.

“The Gatún is the main body of artificial water that ships use to move around the canal and is the one that feeds the freshwater locks,” says Cárdenas Castillero.

. Gatun Lake is the main reservoir that supplies water to the Canal.

However, the passage of each ship carries an extraordinary expense of fresh water.

“On each complete transit from Atlantic to Pacific through the old locks they are spent on average 50 million gallons of water“Explains Vargas.

To get an idea, that implies that, for the passage of a single boat, the volume of water that 75 Olympic swimming pools would need to fill is used.

And if we take into account that, in normal times, about 35 boats pass through the canal every day, then the amount of water spent is around 2,590 Olympic swimming pools per day.

. 50 million gallons of water are spent for each ship that passes through the oldest locks on the Canal.

According to Vargas, this was one of the problems they tried to solve when new locks were designed for the Canal at the beginning of this century, some remodeling tasks that culminated four years ago.

“In the new locks there were three elements that allowed optimizing the use of water,” he says.

“The navigation channel was deepened to guarantee a greater draft, the operating level of the navigation lake (Gatún) was raised and the locks were designed with a water reuse system that reduces consumption with 60% water savings ”, Indicates.

However, even with new tubs that help reuse water in the new locks, Panama loses almost 20 million gallons of fresh water (about 30 Olympic pools) for every step of a ship.

“As water is such an important factor in moving ships, the Canal authority is always very attentive to what is the level in Gatun Lake, because is what makes the Canal work“Explains Cárdenas Castillero.

The lake dries up

However, the low levels of rainfall in 2019 have put those responsible for the Canal on alert since the middle of last year.

“The year was among the driest that Panama has had, we had a strong El Niño and there was also an increase in temperatures and variability in rainfall,” says the hydrologist.

In his opinion, another factor that affected it was that there was a “greater transpiration of the bodies of water” that feed the waterway.

According to an ACP study, the temperature level in the Canal watershed area increased between 0.5ºC and 1.5ºC, which increased evaporation levels of Gatun and Lake Alhajuela, another dam by 10%. built in 1935 also to help the passage of ships.

“To this is added that the water consumption of the populations in the Canal watershed is high, so this situation logically causes some alarm,” says Cárdenas Castillero.

. Through the Canal almost 6% of world trade passes.

According to Vargas, the lack of rain led to Gatun levels being “well below average”, forcing them to take measures to limit water consumption.

“As the year progressed and seeing the rain deficits, it was decided not to make hydroelectric generation in the Gatún dam and the hydraulic aids were also eliminated, which was a way in which ships were helped to enter with greater force into the cameras ”, he points out.

However, the 2019 rainfall was not enough and that’s when they decided to establish a quota for water consumption.

“It was projected that Gatun levels could drop to a point that would affect the operation of the panamax locks (operational since 1914) and neopanamax (those expanded in service since June 2016), so it was necessary to propose adjustments and operational changes “Says Vargas.

The Canal in times of coronavirus

According to Canal authorities, the new charge is here to stay: water consumption rates will continue to be charged even if Gatun levels are restored.

Hence, if the flow of ships is similar to that of previous years, the profits reported by the ACP for the use of the Canal will also increase.

According to official data, at the end of fiscal year 2019, a record figure of 450 million tons of cargo circulated between the two oceans and annual revenues reached US $ 3,365 million, the highest since 1914.

. Could the new tariffs have a negative influence on the circulation of ships?

However, one of the questions for the future is what will be the impact of the coronavirus and the crisis it will generate on world maritime traffic and on the Canal.

One of the great challenges for ACP in recent months has been keeping it operational and preventing contagion from spreading among its employees.

But beyond this, according to the Canal authorities, for the moment, the instability that the covid-19 has generated throughout the world has not been felt directly on the seaway.

Data from the last two months indicate that the number of ships that cross it has only decreased by one on average (it dropped to 34 of the 35 that used to pass each day) and that the queue of ships waiting to transit remains at normal levels .

But the question is what will happen in the months to come.

“The Panama Canal team will closely follow how supply chains are restructured in the coming months. When the coronavirus pandemic subsides, we will also monitor how consistently and aggressively governments regulate the transportation industry, “the Panama Canal administrator said in a statement, Ricaurte Vásquez.