The drill bit dropped through limestone and then hit something nobody had planned for.
Karst groundwater surged into the anchor tunnel at the bridgehead of a suspension bridge over the Huajiang Grand Canyon in Guizhou, China.
The crew could pump it out and keep pumping for the life of the bridge.
Or they could do something else entirely.
What they did is now visible from the road deck, 2,051 feet above the river, as a curtain of falling white water nearly 1,000 feet wide.
Why limestone was the one thing the crew could not ignore
The Huajiang Grand Canyon cuts through some of the most deeply folded karst terrain on earth. Karst rock is limestone that groundwater has been hollowing out for millions of years, leaving it riddled with fissures, voids and underground rivers. What looks solid from the surface can be more sponge than stone a few feet down.
The consequence for a bridge with a main span of 4,660 feet is severe. Porous rock is more prone to erosion, which undermines the stability of anything fixed into it, so the engineers drove their cable anchor chambers far deeper than usual, boring roughly 310 feet into the rock for each tower to reach formation solid enough to hold. That is about as deep as a 25 story building is tall, driven straight into the canyon wall.
At those depths, in karst country, hitting a flow of pressurized groundwater was not a surprise. What the team did with it was the unusual part.
What the bridge actually does, and who it connects
The canyon crossing stitches together a province that mountains had been cutting apart for generations. Before the bridge opened, getting from one rim to the other took about 70 minutes over mountain passes and by ferry. That crossing now takes little more than a minute. For residents heading to a school or a clinic, that is the number that matters.
Guizhou has been economically depressed and, for much of its history, isolated from the rest of China by its karst topography. The bridge carries the S57 Liuzhi, Anlong Expressway over a gorge the route had no way to bypass, linking communities the terrain had made nearly unreachable. It is not a showpiece for a city.
Guizhou’s more than 32,000 bridges, built or under construction, weave a transport network that has earned the province a reputation as the world’s bridge museum.
The numbers that make the height real
The Huajiang Canyon Bridge crosses the Beipan River and is the world’s highest bridge, measuring 2,051 feet from the deck to the river below. The previous record holder, the Duge Bridge on the same river about 120 miles upstream, stands 1,854 feet above the water, so the new mark clears it by roughly 200 feet.
For scale: Horseshoe Falls at Niagara drops about 167 feet, and you could stack twelve of them and still sit about 50 feet below the Huajiang deck.
The bridge runs about 9,480 feet in total length. The deck is a steel truss assembled from 93 segments weighing roughly 22,000 tons. Before opening, engineers drove 96 trucks with a combined weight of more than 3,300 tons onto the deck in a load test, watching every sensor for movement.
How the groundwater became a feature, not a problem
Crews boring the tunnel at the bridgehead hit a flow of karst groundwater and, rather than discharge it as waste for the life of the structure, the team captured it. The reservoir they built holds 140,000 cubic feet and serves a double purpose, supplying the rest area at the bridgehead and watering farmland and orchards on the Guanling side of the canyon.
The surplus is pumped to the middle of the bridge and released, creating a misty waterfall 984 feet wide that falls close to 2,000 feet toward the river, lit by lasers after dark. The same groundwater that could have worked away at the rock now marks the midpoint of the crossing for every driver who passes. No other bridge is known to do this.
Other large crossings solve their water problems by sealing them out. The tunnel boxes being sunk beneath the Baltic are engineered to exclude water entirely. At Huajiang, the water was given a job instead. A Guizhou infrastructure official noted in state media that the design “turns an engineering difficulty into a landscape feature that serves the local community.”
What the canyon received when the bridge opened
The bridge opened to traffic on 28 September 2025, and the canyon that was once a barrier is now the focus of tourism, with viewing skywalks, a sightseeing elevator in one tower and an extreme sports center planned at the bottom of the gorge.
Transporting large components across the rocky terrain required disassembling them into modules. Once on site, they were assembled and lifted into position using one of the world’s largest cable cranes, which spanned the gorge between the two towers. Everything the crossing needed arrived in pieces and was rebuilt over open air.
Meanwhile, the steel arch spans floated up the Hudson needed 30 hours per crossing and a jack lift of 60 feet. The Huajiang crew had no river to float anything on, only a canyon wider than the main span of the Golden Gate and a drop deeper than any bridge had worked over before.
The aquifer is still running. The waterfall has no plans to stop, and the Beipan River below receives it as though it was always there.
