For more than a century, two enormous structures cutting across the desert southwest of Egypt’s famous Red Pyramid have been assumed to be ancient transport features—perhaps roads or ramps used to haul limestone blocks during pyramid construction. However, a new study argues that archaeologists may have been looking at the wrong answer all along.
Instead of transportation infrastructure, researchers now suggest the mysterious earthworks could represent a nearly 4,600-year-old sophisticated hydraulic engineering system, with two giant dams built to capture, regulate, and redirect water through the desert landscape.
If confirmed, the discovery would dramatically revise our understanding of how the builders of Egypt’s pyramids engineered not only stone, but water itself.
The new research, published in Nature Heritage Science, combines satellite imagery, historical maps, digital elevation modeling, watershed analysis, and paleoclimate data to reexamine the little-studied features at Dahshur, the royal necropolis where Pharaoh Snefru built both the Bent Pyramid and the Red Pyramid.
While no excavation has yet confirmed the interpretation, researchers argue that the structures display multiple characteristics far more consistent with dams than with construction ramps.
“This study presents, for the first time, evidence of two ancient, giant dams built across Wadi Dahshur, Egypt, along with a water diversion channel west of the Red Pyramid,” researchers write. “Satellite imagery and watershed mapping show that the two long structures, previously interpreted as stone transport ramps, exhibit the technical signature of dams, each extending 600–700 m and anchored to the valley flanks.”
The findings add a fascinating new chapter to one of archaeology’s enduring mysteries. How did ancient Egyptians organize the enormous logistical operation required to construct the pyramids during the Fourth Dynasty?
The Red Pyramid, completed around 2600 BCE during Snefru’s reign, is widely recognized as Egypt’s first successful “true” pyramid. Scientists have spent decades studying the monument itself. However, much less attention has been devoted to the surrounding landscape and the engineering systems that may have supported its construction.
According to researchers, the wider landscape may have been far more technologically sophisticated than previously appreciated.
The two massive structures stretch approximately 2,000 to 2,300 feet (600 to 700 meters) across Wadi Dahshur. Earlier researchers interpreted one as a transport route leading from nearby quarries while considering the other a natural rise in the terrain. However, the new analysis points to several features that appear difficult to reconcile with those interpretations.
Rather than following the valley, both structures run directly across it, anchoring into the surrounding hillsides much like embankment dams. One also contains a distinctive zigzag geometry that the researchers argue resembles a duckbill spillway—a specialized overflow design still used in modern hydraulic engineering because it can safely release significantly larger volumes of water than a straight spillway of the same width.
No securely identified duckbill-style spillway has previously been documented from ancient Egypt. So if that interpretation is correct, it would mean that the Dahshur structure is one of the earliest known examples of this type of hydraulic design anywhere in the world.
Researchers believe the two structures may have functioned together as a multi-stage flood-control system.
In their proposed scenario, one dam traps sediment carried by flash floods while allowing cleaner water to pass into a second reservoir. From there, water could have been diverted through an artificial channel running remarkably close to the western side of the Red Pyramid before reconnecting with the surrounding drainage network.
That canal is especially intriguing because it raises the possibility that water may have played a more direct role in pyramid construction than traditionally assumed.
Researchers have long known that the ancient Egyptians exploited waterways for transporting heavy stone. Previous discoveries at Giza revealed harbor basins and canals associated with pyramid construction, while papyrus records from Wadi el-Jarf describe crews transporting limestone by boat during Khufu’s reign.
The newly proposed Dahshur canal could represent another piece of that larger hydraulic network.
If maintained at a stable water level, it could have assisted in transporting heavy materials on barges or water-assisted sleds over relatively flat ground. Even beyond transportation, the water could have supported workers, supplied construction areas, mixed mortar, reduced dust, and later been adapted for irrigation or ceremonial uses.
The hypothesis also depends on a very different view of Egypt’s climate nearly 4,600 years ago.
Today, the Dahshur plateau lies within an extremely arid landscape, making the idea of dams initially seem ridiculous. However, paleoclimate evidence reviewed by the researchers suggests northern Egypt during the Old Kingdom was considerably wetter than it is today.
Although the Sahara was already drying following the end of the African Humid Period, seasonal rainfall appears to have remained substantially higher than modern levels. Even infrequent storms could have produced powerful flash floods racing through normally dry wadis.
The study estimates that while average annual rainfall may have ranged between roughly 2 to 6 inches (50 to 150 millimeters), individual storm events could generate enough runoff to create destructive floodwaters requiring engineered control systems. Rather than depending solely on the annual Nile inundation, Egyptian engineers may also have exploited seasonal runoff flowing through desert valleys.
That broader perspective fits with growing evidence that water management extended well beyond the Nile floodplain itself.
Other nearby examples showing evidence of water management well beyond the Nile floodplain include the famous Sadd el-Kafara dam, located less than 12 miles (20 kilometers) east of Dahshur, which is generally regarded as one of the world’s oldest large dams.
Additional archaeological sites around Saqqara and Giza likewise show increasing evidence of canals, flood-control structures, and carefully engineered landscapes associated with pyramid construction.
Even so, the researchers stress that their interpretation is still a hypothesis awaiting archaeological confirmation.
The structures themselves have never been excavated. Much of the area lies within a military zone, limiting direct access, while centuries of windblown sand have buried much of the earliest construction. Modern roads, pipelines, and other infrastructure have also altered parts of the site, making efforts to reconstruct its original appearance more difficult.
Future excavations will therefore be critical. Researchers hope sediment studies could determine whether deposits behind the structures resulted from flowing water rather than drifting desert sand.
Excavations may also reveal construction techniques, protective stonework, spillway features, and datable material capable of establishing whether the structures truly belong to Snefru’s era.
If those investigations support the new interpretation, they would suggest that Old Kingdom engineers possessed a much wider understanding of landscape-scale hydraulic engineering than previously identified.
More intriguing, the study hints that similar forgotten infrastructure could still lie covered beneath Egypt’s deserts, disguised as ordinary landscape features or misidentified for generations.
“Nevertheless, the convergence of geomorphological evidence, watershed connectivity, hydraulic plausibility, and regional cultural context supports the interpretation of the Dahshur structures as intentional large-scale hydraulic installations rather than incidental landscape features,” researchers write. “Other hydraulic structures are most probably lost in the desert, waiting to be identified as such.”
The recent study, “Two possible ancient dams near the Red Pyramid on the Dashur Plateau, Egypt,” by Xavier Landreau, Guillaume Piton, and Sayed Hemeda, appeared in npj Heritage Science.
Tim McMillan is a retired law enforcement executive, investigative reporter and co-founder of The Debrief. His writing typically focuses on defense, national security, the Intelligence Community and topics related to psychology. You can follow Tim on Twitter: @LtTimMcMillan. Tim can be reached by email: tim@thedebrief.org or through encrypted email: LtTimMcMillan@protonmail.com