Flooding of the Nile

The festival of the Nile as depicted in Norden's Voyage d'Egypte et de Nubie

The flooding of the Nile (Arabic: عيد وفاء النيل‎‎) has been an important natural cycle in Egypt since ancient times. It is celebrated by Egyptians as an annual holiday for two weeks starting August 15, known as Wafaa El-Nil. It is also celebrated in the Coptic Church by ceremonially throwing a martyr's relic into the river, hence the name, Esba` al-shahīd ('The Martyr's Finger'). Ancient Egyptians believed that the Nile flooded every year because of Isis's tears of sorrow for her dead husband, Osiris.

The flooding cycle

The Egyptian year was divided into the three seasons of Akhet (Inundation), Peret (Growth), and Shemu (Harvest). Akhet covered the Egyptian flood cycle. This cycle was so consistent that the Egyptians timed its onset using the heliacal rising of Sirius, the key event used to set their calendar.

The first indications of the rise of the river may be seen at the first of the cataracts of the Nile (at Aswan) as early as the beginning of June, and a steady increase goes on until the middle of July, when the increase of water becomes very great. The Nile continues to rise until the beginning of September, when the level that remains stationary for a period of about three weeks, sometimes a little less. In October it rises again, and reaches its highest level. From this period it begins to subside, and though it rises yet once more and reaches occasionally its former highest point, it sinks steadily until the month of June when it is again at its lowest level. Flooding reached Aswan about a week earlier than Cairo, and Luxor 5 – 6 days earlier than Cairo. Typical heights of flood were 45 feet (13.7 metres) at Aswan, 38 feet (11.6 metres) at Luxor (and Thebes) and 25 feet (7.6 metres) at Cairo. (This gives the picture before the construction of the lower and high Aswan dams.)

Importance for Egypt

Sundown and the flooded valley near Cairo

If it were not for the Nile River, Egyptian civilization could not have developed, as it is the only significant source of water in this desert region. Its other importance was the fact that it was their gateway to the unknown world. The Nile flows from south to north, to its delta on the Mediterranean Sea. It would flood each year, bringing in silt-laden waters; when the waters receded the silt would stay behind, fertilizing the land for growing crops. If a flood was too large it would wash over mud dykes protecting a village. A small flood or no flood at all would mean famine. A flood must be of just the right intensity for a good season.

The ancient Egyptians did not realize that the flood in fact appeared due to rains on the mountains to the south, and it was seen as the annual coming of the god. The rains would swell the different tributaries and other rivers that joined to become the Nile River.

End of the flooding

In 1970, with the completion of the High Dam at Aswan, the annual flooding cycle in Egypt came to an end. Today, farmers must use fertilizers to keep their land productive, as the deposits of silt no longer occur each year. Flooding still occurs above the dam in modern-day Sudan.

See also

• Nilometer