The rain that should be filling Gatún Lake is falling everywhere except where it should. Panama sits under a wet season that began in May and normally leaves the canal's reservoirs brimming by December. Instead, cumulative rainfall across the watershed between May and August 2026 was 34% below the historical average, and water flowing into the lakes was down 44%, according to the Panama Canal Authority (ACP), the state entity that runs the waterway. A widely anticipated El Niño weather pattern, only officially confirmed by US forecasters in June, is intensifying faster than anyone at the ACP expected.

And the consequence is blunt. Daily transit slots fall from 36 to 34 on September 4 and to 32 on September 15, the ACP told shipping lines in an advisory. Maximum permitted draft, the depth a loaded ship can sit in the water, has already dropped to 14.78 metres and will fall again to 14.63 metres in early September and 14.48 metres on October 1, well below the 15.24-metre maximum. Every centimetre shaved off draft means a containership must leave cargo on the dock rather than sink lower into the lake.

A canal that has done this before, only worse

Panama has been here before. The 2023-2024 drought forced the ACP to cut transits from 38 to 22 a day and slash draft to 13.4 metres, a reduction that rippled through global freight rates for the best part of a year. What makes 2026 different is timing and duration. Jorge Luis Quijano, a former ACP administrator, told La Prensa that NOAA forecasting models now put the probability of El Niño persisting through April 2027 at 97%, with a 90% chance the event turns severe before the year is out. Panama went from one of its wettest starts to a year on record — January to March ranked second-highest in 77 years of measurements — to one of its driest Augusts, fourth-lowest in the same period. Whether the canal avoids a repeat of 2023 hinges on a single month. If Gatún and Alhajuela lakes have not refilled by the end of November, Quijano warned, "we will be in trouble next summer."

The ACP's outgoing administrator, Ricaurte Vásquez, who hands over to his deputy Ilya Espino de Marotta in September, has framed the response around an eight-month planning horizon rather than a knee-jerk reaction to today's rainfall. That is prudent engineering. It does not change the arithmetic facing shippers now.

Record prices, and Americans will feel it

Roughly 5% of global seaborne trade transits Panama, and close to 70% of that cargo starts or ends its journey in the United States. Container lines have already begun passing the cost of scarcity onto customers. CMA CGM will apply a $500 per TEU Panama Canal surcharge on Far East cargo bound for the US East and Gulf coasts from September 10, MSC has introduced its own surcharge on the same lane, and spot rates from the Far East to the US East Coast have jumped 234% year-on-year to over $10,000 per 40-foot container. Auction premiums for priority slots, once averaging around $135,000 before this year's Middle East crisis, spiked as high as $4.6mn in August, when South Korea's SK Shipping paid to jump the queue for a liquefied petroleum gas carrier. A container ship secured a Neopanamax slot for nearly $4mn days earlier.

None of this happens in isolation. The US-Israel war with Iran has effectively shut the Strait of Hormuz, another chokepoint the world's tankers depend on, pushing extra tonnage towards Panama at precisely the moment its capacity is shrinking. Some shippers are choosing the long way round, via the Cape of Good Hope, adding 10-14 days to a voyage and its own fuel bill to the final invoice.

American consumers rarely notice a single canal transit fee. What they notice, eventually, is the cumulative effect on everything from pharmaceutical ingredients sourced from China to fresh produce and electronics, particularly if cargo owners with no slack in their schedules keep paying record premiums rather than wait. Logistics firms are already rerouting freight to West Coast ports and onto rail and trucking networks that were not built to absorb it, spreading the cost of a Panamanian drought across the US interior.

Río Indio, the fix Panama keeps deferring

The ACP has a long-term answer sitting on the table, and it has sat there for two decades. The Río Indio reservoir project, first identified as a strategic necessity in the ACP's 2006 Master Plan, would flood 4,600 hectares west of the existing canal and pipe water to Gatún through a 9km tunnel, adding enough capacity to sustain around 12 extra daily transits during a water crisis, according to Quijano's estimate. The price tag is $1.6bn, with construction pencilled in for 2028 to 2031.

The project's human cost is why it has stalled. Some 3,375 families across more than 230 rural communities would see their land submerged. Vásquez himself concedes the obstacle is not engineering but "social consensus", and Panama's government has left the ACP, an autonomous state entity answerable to no elected ministry, to sell the reservoir to the people who will lose their homes for it. That approach has produced accusations of opacity and demagoguery from critics writing in the Panamanian press. It also leaves a two-million-strong metropolitan population that shares the canal's water supply exposed to the same droughts as the shipping lanes, since roughly half of Panama's population draws drinking water from the same lakes.

Environmental risk compounds the social one. Flooding farmland to build a reservoir carries the usual costs of habitat loss and displaced agriculture, and campaigners have pushed back against a process that offers little transparency on mitigation. Panama's government, led by President José Raúl Mulino, has been happy to let the ACP absorb that political heat rather than build the national consensus the project needs.

Three governments, one recurring failure

Washington has increasingly treated the canal as leverage rather than simply infrastructure. Donald Trump built a foreign policy narrative around reclaiming American influence over the waterway, conflating two privately operated container terminals with sovereignty over the canal itself. That dispute fed into Panama's Supreme Court stripping Hong Kong-based CK Hutchison of its port concessions, triggering arbitration claims that now exceed $3.5bn. Extending a 90-day waiver in August to let foreign tankers move fuel between US ports, meanwhile, is a tacit admission that Washington's own Hormuz confrontation is adding to the strain it complains about at the other chokepoint.

Beijing's response, quietly detaining Panama-flagged vessels at Chinese ports after the ruling, punished ordinary shipowners for a judicial decision Panama's own courts made, or were pressured into making.

Panama's own government bears the largest share of responsibility for arriving at 2026 unprepared. A drought that returns every two to seven years, and that the ACP's Master Plan flagged twenty years ago, should not still be an emergency. Seizing terminals first and negotiating later, and outsourcing the Río Indio conversation to an unelected canal authority, are choices Panama City made, not choices forced on it by El Niño. The rain will return. Whether Panama has built anywhere to store it by the time the next drought arrives is still, entirely, a political decision.