Dams and reservoirs:
In 1843 it was decided to build a series of diversion dams (barrages or weirs) across the Nile at the head of the delta about 12 miles downstream from Cairo, so as to raise the level of water upstream to supply the irrigation canals and to regulate navigation. This delta barrage scheme was not fully completed until 1861, after which it was extended and improved; it may be regarded as marking the beginning of modern irrigation in the Nile valley. The Zifta Barrage, nearly halfway along the Damietta branch of the deltaic Nile, was added to this system in 1901. In 1902 the Asyūṭ Barrage, more than 200 miles upstream from Cairo, was completed. This was followed in 1909 by the barrage at Isnā (Esna), about 160 miles above Asyūṭ, and in 1930 by the barrage at Najʿ Hammādī, 150 miles above Asyūṭ.
Did the salinity of the Eastern Mediterranean increase?