Panama Canal Drought History: How Water Shortages Keep Squeezing Global Shipping

The Panama Canal is not a sea-level channel cut straight through the isthmus. Panama’s mountainous interior made that impractical, so engineers instead built a staircase of locks that lifts each ship roughly 26 metres above sea level, across Gatun Lake, and lowers it again on the other side. Every lock chamber is filled and drained using gravity-fed freshwater, not seawater pumped in from the Atlantic or Pacific — the system was designed around the Chagres River’s flow, not the ocean beside it. That single engineering choice, made in the 1900s, is the reason a canal touching two oceans can still run short of water: it was never built to use ocean water to lift ships in the first place.

The Panama Canal officially opened on 15 August 1914, cutting the sea voyage between the US East and West Coasts by thousands of miles and removing the need to sail around South America’s Cape Horn for many routes. Panama’s mountainous, unstable interior ruled out a simple sea-level cut, so engineers dammed the Chagres River to create Gatun Lake, at the time one of the largest artificial lakes in the world, and built a staircase of locks around it. The design was brilliant civil engineering — and it permanently tied the canal’s operating capacity to Panama’s rainfall.

Panama’s rainfall is strongly influenced by El Niño, the recurring warm-water climate pattern in the tropical Pacific that tends to suppress rainfall over the isthmus. The ACP and independent researchers have linked reduced watershed rainfall and canal operating pressure to El Niño episodes including 1982–83, 1997–98, 2015–16 and 2023–24. The mechanism is not new: what has changed since the 1990s is that ships are larger, trade volumes are higher, Panama’s own population and water demand have grown, and the Neopanamax locks (2016) added new demand alongside the original system — so a comparable rainfall shortfall now carries a bigger economic cost than it did in 1998.

The expanded Panama Canal opened in June 2016, adding new locks that could handle Neopanamax vessels — container ships, LNG carriers and other ships far larger than the original locks could accept. The expansion reshaped the canal’s role in global trade, opening an important route for US Gulf Coast LNG exports to Asia and for larger Asia–US East Coast container flows. Its water-saving basins were a genuine efficiency improvement over the original locks. But as the 2019 and 2023 droughts would show within a few years, saving water is not the same as not needing it — the expanded canal still depends entirely on watershed rainfall to keep those basins, and Gatun Lake itself, full.

Rainfall fell sharply in 2019, and the Panama Canal watershed recorded one of its driest years in decades to that point, pushing Gatun Lake to historically low levels outside a major El Niño year. In response, the ACP introduced a freshwater surcharge in 2020: part of the per-transit fee that varies with Gatun Lake’s water level, rising when the lake is low and easing when it is high. The surcharge turned water scarcity into an explicit shipping cost for the first time — a pricing signal, not just an operational restriction.

The 2023 dry season started early and ran long. As El Niño developed through the year, the ACP recorded total rainfall roughly 30% below normal across the watershed — its second-driest year in a rainfall record stretching back 73 years. October, which should normally help refill the reservoirs ahead of the dry season, instead came in 41% below normal rainfall, the driest October the ACP had recorded since 1950. Gatun Lake fell to some of its lowest recorded levels in the second half of 2023, and the reservoir system could not support normal operations.

The ACP responded by tightening maximum vessel draft repeatedly through the second half of 2023 and cutting daily booked transits step by step, reaching roughly 22–24 ships a day at the tightest point of the crisis — down from a normal-conditions range in the mid-30s. Reservation auctions for scarce transit slots showed just how valuable a guaranteed passage had become, with some shipping companies paying substantial premiums to jump the queue rather than wait, and others rerouting entirely.

Every day a ship waits for a canal slot costs money — crew, fuel, charter fees, inventory delay, missed delivery windows. As Panama’s restrictions tightened through late 2023, some shipping lines chose to reroute rather than wait, in some cases via the Suez Canal, adding significant distance and time to affected voyages. That decision collided with a second, unrelated crisis: attacks disrupted Red Sea shipping and pushed many vessels away from Suez at almost the same time, while the war in Ukraine continued to disrupt Black Sea routes. For several months in late 2023 and early 2024, three major maritime chokepoints — Panama, Suez/Red Sea and the Black Sea — were under pressure simultaneously, and UN trade officials pointed to the combination as a meaningful drag on global shipping capacity and cost, distinct from ordinary port congestion.

Rainfall and aggressive conservation measures outperformed the ACP’s worst-case forecasts heading into 2024. Instead of falling toward the roughly 18 daily transits some models had floated as a downside scenario, the ACP raised capacity to 24 daily transits from mid-January 2024, still well below normal but a clear improvement. As the rainy season developed through 2024, reservoir levels recovered further, draft restrictions eased, and by the second half of 2024 the worst of the crisis had passed. Global shipping had learned something it could not unlearn: the Panama Canal has a hard water limit, and that limit can bind with little warning.

After the 2023–24 crisis, the ACP began conserving water earlier in each cycle rather than waiting for Gatun Lake to collapse. Entering 2026, reserves looked comparatively strong: the canal ran with a 50-foot draft and around 36 daily transit slots into early August 2026, averaging about 35 transits a day through June. That changed as the year’s rainy season underperformed — watershed rainfall from May through August 2026 came in roughly 34% below normal, reversing much of the reservoir gains the ACP had banked entering the year.

The ACP responded with a sequence of draft cuts through July and August 2026 (49.5 feet in early July, down to 48 feet by 26 August), then combined draft and transit-count cuts from September: daily transits fell from 36 to 34 ships from 3 September, with Neopanamax draft reduced to 14.63 metres (48 feet) and Neopanamax/Panamax lock slots trimmed from 10/26 to 9/25. A second cut followed on 15 September 2026, taking daily transits to 32 and Panamax slots down to 23, with a further draft tightening to 14.48 metres scheduled from 1 October. ACP administrator Ilya Espino de Marotta has said rainfall across September, October and November will determine whether slots need to be cut further into early 2027 — and the ACP has already flagged an average of around 29.5 daily transits from October as the current planning baseline, citing a developing 2026–27 El Niño pattern that forecasters expect could suppress rainfall into 2027.