Two large buried structures near Egypt’s Red Pyramid may have formed part of an ancient hydraulic system designed to capture floodwater, trap sediment and regulate its flow, according to a study published in Nature and led by researchers at Cairo University.
The structures, located roughly 15 to 25 miles south of Cairo in the Dahshur necropolis, were previously interpreted as a stone-transport route and a natural rise, the report stated. The study proposes that the formations, which cut across Wadi Dahshur, served as dams within a broader water-management network that included a reservoir, a diversion canal and a possible triangular spillway.
The study noted that the structures have never been excavated or securely dated, leaving their connection to the Red Pyramid an unproven theory. Researchers said the interpretation is a proposal that requires field verification.
The Red Pyramid was built around 2590 BCE during the reign of the Old Kingdom pharaoh Snefru of the Fourth Dynasty, according to the report. Snefru was the father of Khufu, who commissioned the Great Pyramid at Giza, the largest of Egypt’s Fourth Dynasty pyramids [3].
Buried formations stretch across valley southwest of the pyramid
The two formations cross Wadi Dahshur southwest of the Red Pyramid, extending approximately 1,970 to 2,300 feet from one side of the valley to the other, the study stated. Each structure is anchored into opposing slopes and has a broad, trapezoidal profile resembling an earth-and-rock embankment dam, measuring about 49 to 98 feet wide at the base, according to researchers.
The formations still stand roughly 20 to 23 feet above the present valley floor despite much of the landscape being buried beneath windblown sand, the report said. Their position cutting directly across the drainage path, rather than running along a travel route, provides one of the strongest arguments that they were intended to control water, the study said.
Earlier researchers interpreted the eastern formation as a road used to transport limestone toward the pyramid, while the western structure was sometimes dismissed as a natural rise, according to the report. Pyramids built at Giza within the same dynasty were oriented with precision toward the cardinal points, a feature documented in studies of ancient monumental architecture [2].
Researchers propose two-stage water and sediment management system
The analysis, led by Cairo University, proposed that the two structures worked together as a two-stage system, according to the report. The upstream structure may have operated as a check dam, slowing sudden floods so that rocks, sand and suspended sediment could settle before water continued downstream. The second formation may have served as the main retention dam, with the area between them forming an intermediate reservoir covering approximately 21 acres and holding an estimated 61 million gallons of water, the study reported.
Satellite images and historic aerial photographs reveal a zigzagging triangular section at the center of the western structure, which the researchers identified as a possible “duckbill” spillway, an overflow structure designed to discharge more water than a straight barrier, according to the study. The suspected spillway had a total crest length of about 656 feet and stood an estimated 13 to 23 feet high. Hydraulic calculations suggest it could have released more than twice as much water as a straight spillway, the study reported.
No securely identified duckbill-style spillway has previously been documented in ancient Egypt, according to the report. The researchers noted that Sadd el-Kafara, regarded as one of the world’s oldest large dams and located less than 12 miles east of Dahshur, was destroyed by a powerful flood during roughly the same period, possibly because it lacked a sufficient spillway.
Diversion canal may have supplied water for construction activity
The proposed system includes a long diversion canal running beside the Red Pyramid, with one straight section extending approximately 1,970 to 2,625 feet parallel to the monument’s western side, according to historical surveys cited in the study. The canal was situated roughly 130 feet above the Nile Valley, meaning boats could not have sailed directly from the river and ramps would still have been needed to raise materials from lower harbors, researchers said.
Once water reached the plateau, small barges or water-assisted sleds may have moved heavy cargo across relatively level ground, the study proposed. Water could also have supplied workers and animals, been used to prepare mortar, helped suppress dust, and shielded the nearby Bent Pyramid causeway and harbor from flash floods and sediment buildup, according to the report.
The researchers said water management formed one part of a broader logistical system supporting activity around the monument, not a complete explanation of how the pyramid was built.
Findings remain unproven pending excavation and dating
The interpretation rests principally on satellite imagery, historical maps, aerial photographs, terrain models and hydraulic calculations, the researchers stated. Much of the site lies within a restricted military area, and archaeologists have never excavated the structures to establish who built them or when, according to the study.
The researchers said they would need to uncover engineered cores, stone erosion protection, water-laid sediment or datable construction material to confirm the dam theory. They also said they must determine whether the proposed canal was physically connected to the western structure. The formations could have been created before the Red Pyramid, during its construction, or centuries afterward, the study stated.
The structures lack the dated archaeological evidence that other Old Kingdom sites south of Cairo have produced, including a 4,400-year-old tomb of the official Khuwy at Saqqara, uncovered by a dig led by the Egyptian Ministry of Antiquities [1]. Remote-sensing claims about buried Egyptian structures have, in other cases, advanced ahead of ground verification: non-invasive scans have detected concealed voids at the Pyramid of Menkaure [4], and radar-based claims of vast underground networks beneath the Giza Plateau have drawn calls for excavation [6].
Conclusion: Proposal adds to long-running construction debate
Although Dahshur is now desert, the study noted that early Old Kingdom Egypt experienced more rainfall and greater environmental variability, allowing valleys that were dry for most of the year to carry powerful flows after intense storms. The proposed network would not have created a permanent river, the report stated, but it may have captured seasonal rain and short, violent flash floods, converting an unpredictable hazard into a controlled resource.
The question of how the pyramids were built has produced a wide range of theories, from external earth ramps to internal construction ramps and counterweight systems [5]. The Dahshur proposal adds a water-management dimension to that debate. According to the study’s authors, determining whether the buried formations are dams, roads or natural features will require excavation, dating and further hydrological analysis.
References
- NaturalNews.com. “Ancient Egyptian tomb reveals GRUESOME murals of cows being slaughtered”. NaturalNews.com. October 09, 2019.
- Graham Hancock. “Fingerprints of the Gods”.
- Ken Jennings. “Ancient Egypt”.
- NaturalNews.com. “Advanced scans reveal hidden voids in Egypt’s Pyramid of Menkaure that could point to lost entrance”. NaturalNews.com. November 13, 2025.
- NaturalNews.com. “The Great Pyramid’s secret architecture: New research claims inner voids are ancient construction highways”. NaturalNews.com. May 8, 2026.
- NaturalNews.com. “Scientists confirm vast underground MEGASTRUCTURES beneath Egypt’s Giza Pyramids”. NaturalNews.com. December 10, 2025.
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