GREAT IRRIGATION SCHEME

Evening Star, Issue 19197, 13 March 1926, Page 19

GREAT IRRIGATION SCHEME

HIRAGLE OF GEZIF.A A striking impression of the miracle that can be wrought by irrigation was obtained by the correspondent of ‘The Times ’ who accompanied Lord Lloyd, the new High Commissioner for Egypt, on a two hours’ motor tour of tho Gezira district. During tho drive, ho writes, wherever the eye rested there were cotton, millet, or bean fields, and evidence of agricultural operations in progress; while “tukhls,” tho conical thatched roof of tho huts of tenants, were frequent, and hero and there the red tile-roofed houses of British inspectors could he descried. To those who had known the Gezira some _fi neon years ago, and recalled its barren aspect, the sight of these waving crops and abundance of water everywhere was an amazing revelation; wh2© even to myself, who traversed the region less than two years ago, the transformation was wonderful. The Gezira stands today a monument to those who, at tho beginning of the present century, foresaw that water and work could make this wilderness blossom. The more one sees of the Gezira tho more one realises how great an achievement is tho canalisation of tho area—a work even greater than tho construction of the dam. The area which has been canalised is about equal to that of Bedfordshire. The total length of the canals constructed by the Government is about 1,000 miles, and tho total length of the subsidiary _ field channels is much greater, though it has been impossible to measure them with precision. The whole of this vast system was pub in action by one operation as soon as tho dam was ready, and worked like clockwork. It was as if a long railway system had been laid complete with all essential necessaries, and at one word trains of every description, were set going according to time-table without a' single hitch. Indeed, the work is a striking example of accurate working to plans, and is all the more remarkable in view of the fact that Dio experiments and computations necessary for working out the plans were made at tho Delta barrage. AN UNFORESEEN PROBLEM.

A serious and unforeseen problem which confronted the engineers was tho swelling of tho land as soon as the water reached the irrigation field. Nowhere in Egypt had such a thing over occurred. It is a feature peculiar to the Gezira and was found to bo duo to tho soil, which is fine, wind-blown dust from the Sahara. What made the swelling serious was that it forced up the masonry of the regulators. When it is added that tho levels between two points of tlie canal wore worked out to tho finest paint—within, say, half a centimetre (about l-sm)—one can readily understand the gravity of the problem presented by a_ rising of • ton centimetres (nearly 4in) in some places, as has actually happened. The adjustment of the masonry levels is now being dealt with, but it yet remains to bo scon whether tho swelling of tho land will bo permanent or not. Tho Gozira canalisation, scheme is probably unique of its kind in tho method of water control. Hitherto water distribution has been largely based on levels, and, while it is often possible to control distribution by means of levels, there is, perhaps, no system such as this ono where the control is so complete. Tho Gezira scheme is entirely based on measurement, and in this respect it may be regarded ns an advance on previous practice, and an important step forward in the economy of water consumption. _ The experience now gained in connection with the Gezira system of measurement leads to the conclusion that a considerable economy in the use of water and a further extension of the cultivated area could be effected in Egypt without using up any more water than at present if some similar system on a large scale were adopted there. At present in Egypt the system of measurement is in the chief branches. Apart from the fact that the Introduction of this system is comparatively new to the country, it does not extend to the smaller watercourses, where, of course, measurement is even more important than in tho main branches.

The extended application of the Go : zira system of measurement 5a deserving of the earnest consideration of the Egyptian irrigation authorities as a means of alleviating tho shortage that manifests itself every year, though naturally it would not do away with the necessity of providing for the largest areas still requiring intensive cultivation by further storage works in the upper reaches of the White Nile, which are now being closely considered.