Throughout history, there are numerous theories about building the Great Pyramids of Giza along the Nile River in Egypt. One of the key questions has been the logistics of moving the massive stones, each weighing over two tons. 2.3 million of these blocks of limestone and granite were used to construct the structures, without the aid of modern machinery. Theories for how this was accomplished vary and include methods of transport over land via sleds and rollers, and construction on-site using ramps, and pulleys. Some even attribute these other-worldly feats more broadly to the work of aliens.
Water and the Nile have always been tied to these theories, with the idea that the blocks were floated on the river from distant quarries for use on-site for the Pyramid construction. The structures sit at a slightly higher elevation from the floodplain, some distance from the main channels of the Nile, thus there have been questions on how the stones were transported this last mile from the river to the site itself. The research questions used the tools of hidden hydrology to develop theories on lost channels instrumental to the construction. Two such theories are discussed below.
Khufu Branch
Research on a proposed lost side branch of the Nile being used for aiding in construction was discussed in 2022. I read about it in the article “A Long-Lost Branch of the Nile Helped in Building Egypt’s Pyramids.” (NY Times, 08.30.22), which discusses research results from the paper: “Nile waterscapes facilitated the construction of the Giza pyramids during the 3rd millennium BCE” (PNAS, 08.29.22). The article posits the use of a now-defunct Khufu branch of the Nile River that bent towards the assemblage in Giza to aid in transporting the giant slabs of stone to the building zone.
The researcher’s process involved looking at soil cores: “Seeking evidence of an ancient water route, the researchers drilled down into the desert near the Giza harbor site and along the Khufu Branch’s hypothesized route., where they collected five sediment cores.” Analysis of the samples included paleobotany to look at plant fragments and pollen, and matching these species with the presence or absence of water-adapted or dry plantings to determine if the areas were part of a historical water body. The results showed periods of inundation that matched the construction of the pyramids.
This wet period allowed standing water to persist, and the proximity of the Khufu branch provided the ability to extend the reach of the Nile, allowing the construction of smaller canals close to the area of the Giza plateau. The branch is theorized to have dried up around 600 B.C. and the channel moved further away from the site of the Great Pyramids.
Ahramat Branch
Several current articles (Cosmos, BBC) have reignited this dialog around these theories of the use of waterways for transporting building stones. They all refer to research from a May 2024 paper entitled, “The Egyptian pyramid chain was built along the now abandoned Ahramat Nile Branch.” (Nature Communications Earth & Environment, 05.16.24). The research team offers new theories about investigating the hidden hydrology to unlock these ancient mysteries. As noted in the article the team makes a similar assertion to the previous work on the Khufu Branch, however, they consider the hydrology differently as a parallel side channel they refer to as the Ahramat Branch. From their abstract:
“Many of the pyramids, dating to the Old and Middle Kingdoms, have causeways that lead to the branch and terminate with Valley Temples which may have acted as river harbors along it in the past. We suggest that The Ahramat Branch played a role in the monuments’ construction and that it was simultaneously active and used as a transportation waterway for workmen and building materials to the pyramids’ sites.”
The map below shows the route of the Ahrama Branch, which was situated on the western edge of the floodplain closer to the location of the Pyramids. In this case, the proximity extended the length of the Pyramid complex, including those to the south near Memphis. The study offers the opportunity for new information, protection of cultural sites, and outline areas to protect from urban development.
The research team discusses the project directly in an article: “We mapped a lost branch of the Nile River – which may be the key to a longstanding mystery of the pyramids.” (The Conversation, 05.16.24). They discuss the methodology of using satellite images, digital elevation models, historical maps, and other sources to identify the traces of the waterway. As they note, there are ‘causeways’ that look to connect at the points of the major construction areas, which were used as “docks” for loading and unloading materials and for workers moving up and down the river.
The idea of understanding the historical hydrological elements of the river provides a unique approach, noted by the team:
“This research shows that a multidisciplinary approach to river science is needed to gain a better understanding of dynamic river landscapes. If we want to understand and protect the rivers we have today – and the environmentally and culturally significant sites to which they are inextricably tied – we need a greater appreciation of the interconnected factors that affect rivers and how they can be managed.”
Similar to the Khufu branch, there are theories about what eventually happened to the Ahramat Branch. These include the gradual migration of the channel, tectonic shifts that changed the floodplain drainage, or accumulation of sand filling up the channel, concurrent with other desertification processes at work. The climatic shifts could also have led to more arid conditions and dissipation of the side channel due to lower flows.
Check out the articles and papers for much more detail. I appreciate these larger-scale investigations of hidden hydrology, especially when they intersect with the complexity of ancient constructions, providing hints of how water was instrumental in these monumental endeavors. It shifts the attention away from the typical urban focus of hidden hydrology, which concentrates on the burial and piping of streams in cities, positioning the investigations of hydrology through bigger contexts and longer timescales. And, it’s a pretty cool way to solve a mystery.
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Note: This post was originally posted on Substack on 05/21/24 and added to the Hidden Hydrology website on 04/23/25.