Irrigation Schemes in Egypt and the Sudan

Abstract

AFTER alluding to ancient indigenous methods of providing water for crops, Sir Murdoch Macdonald proceeded to discuss the modern system of perennial irrigation (under which provision has also to be made for drainage) adopted in consequence of the introduction of cotton cultivation by the Khedive, Mohammed Ali. The first work of construction in that connexion was the Delta Barrage, completed in 1861, but, owing to defects in the foundations, not brought into effective use until the British occupation, when the works were strengthened. The succeeding structures of the same type at Assuan, Asyut, Esna and Nag Hammadi were historically noticed, and then reference was made to various schemes put forward from time to time for impounding the water of the Blue Nile and the White Nile above Khartoum. Figures were quoted to show the benefit to Egypt of the Assuan Dam. The 1,000 million cubic metres of water originally impounded would be increased bv the re-heightening to at least 4,800 million cubic metres and the normal summer supply would be increased by about 66 per cent. The contemplated Gebel Aulia reservoir would contain about 3,000 million cubic metres and would possibly be able to pass 2,500 million into the river. A Lake Albert Dam, only 8 metres in height, would impound about 40,000 million cubic metres, but would require to be coupled with works which would conserve the waters as they passed down the river and prevent their being wasted as at present in the Sudd region. Sir Murdoch touched upon the schemes put forward for preventing the immense loss of water due to evaporation from the marsh formed by the main stream between the Sobat and Bahr-el-Ghazal. The whole territory including the marsh region has an area of about 90,000 square miles and might become a wonderful timber growing country. Summing up the position between Egypt and the Anglo-Egyptian Sudan, he said that the large volumes of water passing in flood, of which Egypt can only use a small part, would make it possible for the Sudan to divert a great quantity without detriment to her neighbour. All the conceivable diminution by future reservoirs would not be sufficient to reduce the flood volume below the known requirements of Egypt for the fertilisation of its flood crops.