Among all the Greek travelers, Herodotus is the only one to have visited this region (in 460 BC) prior to the new hydraulic works implemented by Ptolemy II in the 3rd century BC. Having admired the Labyrinth, the funeral monument of Amenemhat III, he then describes a lake of very large dimensions, oriented approximately north-south:
“Such was the labyrinth; but an even greater marvel is what is called the Lake of Moeris, beside which the labyrinth was built. The circuit of this lake is a distance of about four hundred and twenty miles (670 km!), which is equal to the whole seaboard of Egypt. The length of the lake is north and south, and its depth at its deepest is fifty fathoms (89 m). That it is handmade and dug, it itself is the best evidence. For in about the middle of the lake stand two pyramids that top the water (these are the colossi ofBiahmou), each one by fifty fathoms, and each is built as much again underwater; and on top of each there is a huge stone figure of a man sitting on a throne. The water that is in the lake is not fed with natural springs, for the country here is terribly waterless, but it enters the lake from the Nile by a channel; and for six months it flows into the lake, and then, another six, it flows again into the Nile.”[112]
One would hope that this account reflects the work of the pharaohs of the XIIth Dynasty, but Herodotus’ account is from more than a thousand years later. Herodotus is in fact describing the rather sad sight of the depression’s complete inundation, consistent with the geological descriptions cited earlier. The dimension that Herodotus indicates (a perimeter of 640 km), and the fact that the colossi of Biahmou are “in the middle of the lake” leave no doubt that this is the case.[113] The alternating current in the Joseph canal was probably, at this period, a simple natural phenomenon caused by season variations in the level of the Nile, unregulated by man.
And yet, as we have said, there logically must have been one or more temporary reservoirs to store and distribute the flood waters in the era of Amenemhat III, distinct from the Qaroun lake that occupied the lowest portion of the depression. These reservoirs were situated above the irrigated lands, very likely near Shedet — Crocodilopolis and the mouth of the Joseph canal. Field studies conducted in 1988[114] made it possible to reconstitute the boundaries of a vast reservoir, located on the heights to the south of the depression as expected. The southern portion of the boundary approximately follows the contour +17 m, and to the north it is closed by a dam. This dam of Mala’a is 8,000 m long and four to five meters high. But the only remnants of its masonry construction that are visible today date from the Ptolemites (3rd century BC) — along with remnants of repairs from the Roman and Islamic eras. Older vestiges have not been found. The visible traces of the Illahoun dike (remains dating also from the 3rd century BC) suggest that it was 5 km long and four meters high. It is unlikely that we will ever know the details of engineering developments from the period of Amenemhat III with any certainty. Since the Ptolemite engineers gave the ancient name lake of Moeris to their reservoir, it is possible that their work more or less replicated the preexisting system — but this is only speculation.
There remains another question: what has been the evolution of the “normal” level of lake Qaroun across the ages of its existence? As we have seen, the altitude of the monuments erected in the XIIth Dynasty argue for a lake whose surface is approximately at elevation +10 m. It rises to +20 m when the Fayoun Depression is not isolated from the valley, and fluctuates with the floods. In the Ptolemite period, as we will see later on (Figure 5.8), the new developments will be around elevation 0 (even -10 m), an altitude that is surely suggestive of the lake level at that time. It is likely not until the time of the Romans that the lake level was lowered to its present level, 45 m below sea level, to increase the amount of tillable land.
Fayoun owes its history as one of the most productive regions of Egypt to the hydraulic works of the successors of Alexander the Great. Strabo visits the region in 25 BC (the labyrinth remains one of the most attractive curiosities to travelers), long after these new works have been implemented:
“It still remains that the lake of Moeris, by its dimensions and its depth, is capable of containing, during the floods of the Nile, the excess water, without overflowing onto inhabited places and their crops; and at the moment when the river waters recede, it is capable of returning this excess water by the same canal, in each of its two outlets, while keeping within itself and the canal, a reserve of water to feed the irrigation canals. Whatever be the acts of nature, they have placed locks (ports or gates?) by means of which the engineers regulated the flow of water that enters and leaves.” (Strabo, Book XVII, 1-37)
Thus it is indeed the great reservoir of Mala’a that Strabo describes as the “lake of Moeris ”, rendering unwitting homage to the nearby remains of the old pharaoh.
