The Panama Canal does something that the Suez Canal does not need to do: it lifts ships uphill. Because the Atlantic and Pacific oceans are at substantially the same sea level but the spine of mountains running through Central America rises hundreds of metres in between, a true sea-level canal across Panama would have required excavating an enormous trench through a mountain range. The actual canal, completed in 1914 after a generation of failed attempts, takes a different approach: it raises ships 26 metres above sea level using a series of locks at one end, sails them across an artificial mountain lake, and then lowers them back down with another set of locks at the other end. A ship transiting from the Caribbean to the Pacific spends about eight hours in the system. It pays a toll of roughly $300,000 to $1 million depending on its size. And it avoids the roughly 13,000-kilometre journey around Cape Horn that was the only alternative before 1914.
The Geography
The Isthmus of Panama is the narrowest land barrier between the Atlantic and Pacific oceans, only 80 kilometres wide at its narrowest point. The terrain is tropical jungle, with the Cordillera Central mountain range running roughly east-west through the middle. The canal route runs roughly southeast-to-northwest from Cristóbal on the Caribbean coast (near Colón) to Panama City on the Pacific. Counterintuitively, the Pacific entrance is east of the Caribbean entrance — Panama bends sharply so that the country runs east-west rather than north-south through this section. The canal's actual length is 82 kilometres, including the approach channels at both ends. The total elevation change from sea level to the high point at Gatun Lake is 26 metres, achieved by a flight of three locks at each end.
The Atlantic and Pacific Entrances
The Caribbean entrance to the canal is at Cristóbal, adjacent to the city of Colón at the mouth of the Chagres River. Colón is the second-largest city in Panama and a notable free-trade zone — the Colón Free Zone is the largest free zone in the western hemisphere by volume of trade. The Pacific entrance is at the Bay of Panama, with Panama City — the capital and largest city of the country — overlooking the entrance from its high-rise downtown skyline. The contrast between the two entrances is striking: the Caribbean side is humid jungle backed by a modest port city, while the Pacific side opens directly into the financial and tourist centre of the country. Panama City's skyline of glass-and-steel towers (about 350 buildings over 100 metres tall, more than any other city in Central America) is the country's commercial centre and looks out over the canal's southern approach.
Why Panama and Not Nicaragua
Throughout the 19th century, two competing routes for a Central American canal were debated: across Panama, or across Nicaragua via the San Juan River and Lake Nicaragua. The Nicaragua route was longer (about 280 kilometres of canal works compared to 80 in Panama) but had two advantages: more of its length consisted of natural lake and river that needed only modest improvement, and the elevation profile required fewer locks. American congressional debate through the 1890s and early 1900s went back and forth between the two routes. The decisive lobbying effort by Philippe Bunau-Varilla, the French engineer who had inherited the assets of the failed French Panama company, included the famous gesture of sending each US senator a Nicaraguan postage stamp depicting a smoking volcano — Mount Momotombo, near the proposed canal route. The implicit message that Nicaragua was geologically unstable swung enough senate votes that the Spooner Act of 1902 chose the Panama route. Whether the Nicaragua route would have produced a different long-run history is unknowable.
The Failed French Attempt
Construction was first seriously attempted by a French company under Ferdinand de Lesseps, the same engineer who had succeeded brilliantly at Suez two decades earlier. The Compagnie Universelle du Canal Interocéanique was formed in 1879 and began construction in 1881. It immediately ran into the dual problems that would defeat it: the terrain was a wet, mountainous tropical jungle requiring vast excavation, and the disease environment was lethal. Yellow fever and malaria killed an estimated 22,000 workers during the French attempt. The original plan was for a sea-level canal like Suez, but the engineering proved impossible and the company's funds ran out. Suspicion of corruption and incompetence brought criminal charges against the company's directors, including de Lesseps himself, in the so-called Panama scandals of the 1890s. The French attempt collapsed in 1889 with about a third of the necessary excavation completed.
The American Construction
The United States acquired the right to build a canal across Panama through an extraordinary sequence of events in 1903. The Hay-Herrán Treaty between the US and Colombia (which then included Panama) was rejected by the Colombian senate. Within months, with substantial covert American support, a small group of Panamanian elites declared the independence of Panama from Colombia. US warships in Panamanian harbours prevented Colombian military intervention. Within days, US Secretary of State John Hay and the French engineer Philippe Bunau-Varilla (representing the newly independent Panama before its government had even been formed) signed the Hay-Bunau-Varilla Treaty granting the US perpetual control over a 16-kilometre-wide Canal Zone across Panama. The treaty was deeply unpopular in Panama and became a perpetual political grievance.
American construction began in 1904. The early years were nearly as disease-stricken as the French period until Dr William Crawford Gorgas — the US Army surgeon who had eliminated yellow fever in Havana — implemented systematic mosquito-control measures: draining standing water, fumigating buildings, installing screens, and treating yellow fever cases aggressively. By 1906 yellow fever had been effectively eliminated from the Canal Zone. The engineering itself was redesigned by the American team under Chief Engineer John Stevens (until 1907) and George Washington Goethals (after 1907) as a lock-and-lake canal rather than the sea-level cut the French had attempted. The Chagres River was dammed at Gatun to create an artificial lake at 26 metres elevation, and the canal was cut to meet the lake at both ends.
The Locks
The canal locks are massive concrete structures, each 320 metres long, 33.5 metres wide, and 13 metres deep. The original size accommodated ships smaller than 290 metres long and 32 metres wide, a size that became known in shipping as "Panamax." As container ships grew through the 20th century, eventually exceeding Panamax dimensions, a substantial portion of global trade became unable to use the canal. A parallel set of larger locks (called the Third Set of Locks, or the New Panamax/Neopanamax expansion) was approved by Panamanian referendum in 2006, constructed from 2007 to 2016, and opened in June 2016. The new locks accommodate ships up to 366 metres long and 49 metres wide. About 96 percent of the world's container fleet can now use the canal, including the largest container ships ever built.
The Handover
The Carter-Torrijos Treaties of 1977 — signed by US President Jimmy Carter and Panamanian general Omar Torrijos — committed the United States to transfer the canal to Panamanian sovereignty by the end of 1999. The treaties were politically controversial in both countries: many Americans saw them as a giveaway of strategic infrastructure, while many Panamanians saw the gradual transfer as too slow. The actual handover ceremony on 31 December 1999 transferred administration to the Panama Canal Authority, an autonomous Panamanian state agency. The handover went smoothly. Canal operations continued without interruption. Revenue, which had previously gone to the United States, now flows to Panama's national budget — typically around $2-3 billion per year, making the canal one of the largest single contributors to Panamanian government revenue.
The Water Problem
Every ship that transits the canal uses approximately 200 million litres of fresh water from Gatun Lake to fill and empty the locks. This water flows out to either ocean and is lost. The lake is replenished by rainfall in the surrounding watershed. In normal years this works. In drought years — which have become more frequent with climate change — the water level in Gatun Lake drops, and the canal authority is forced to reduce both the maximum ship size and the daily transit count. The 2023-2024 drought period reduced canal capacity by roughly 30 percent at its worst, and several shipping companies considered rerouting through Suez or around Africa. Panama is investing in alternative water sources — particularly the proposed Indio River reservoir — to reduce future drought vulnerability. Whether climate change will allow these investments to keep pace with worsening conditions remains an open question.
What Comes Next
The canal's commercial position is more secure than it has been since the rise of supertankers in the 1960s. The 2016 expansion captured most of the trade that had grown too large for the original locks. The Panamanian state's investment in the canal continues to produce major returns. The political relationship with the United States, complicated by Trump's repeated 2024-25 statements suggesting the US should reclaim the canal, has added a layer of uncertainty that did not exist a few years ago. Operationally, however, the canal is running well, with steady traffic, ongoing infrastructure investment, and a stable governance arrangement. The 82 kilometres of artificial waterway across the isthmus continues to deliver one of the most significant pieces of value created by 20th-century engineering.
