Is the Nile River Saltwater or Freshwater?

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The Nile is a freshwater river, and it supplies Egypt with the majority of its fresh water. Historically, Nile River civilizations were able to avoid the problem of excessive salt ruining arable land by using the natural flooding of the Nile rather than irrigation to water their crops.

Since the building of the Aswan Dam, however, salt has been accumulating in the river because it no longer flows strongly enough to keep salt water from the Mediterranean Sea from accumulating in the Nile as backwash. The increased salinity has not changed the Nile from a freshwater river to a saltwater river, but it has caused environmental issues, because salt is also accumulating in the soil and decreasing its arability.