Chapter XI: Schemes for the Future

The completion of one programme by the construction of the Reservoir and the works dependent upon it does not mean stagnation. Irrigation is an ever-growing and ever-living science. There can be no standing still. Even in the ordinary routine there are thousands of details always pressing forward for fresh consideration. It takes but a few years for a daring innovation to become old-fashioned. The system of perennial irrigation in Egypt is so young that there is still much to be learnt. It means a totally new style of agriculture. Nothing but constant experiment and constant watchfulness will enable the engineers to distribute the water to the best advantage. The best methods of reclaiming new land, and of preventing the deterioration of the old, the maintenance and improvement of existing locks, weirs, regulators, barrages, and other masonry, the care of canals and drains—these and an infinity of other matters fill the life of the irrigation engineer, so that, always interesting, it is also at times even exciting. Decisions of great and immediate importance have to be constantly and promptly taken. Their duty touches very nearly the lives of all who dwell and labour within their districts. There can be no question of any folding of the hands to slumber. But beyond all this, it is the peculiar good fortune of those whose care is the water-supply of Egypt that they have to travel in thought or in fact over half a great continent, and discuss schemes of a magnitude and extent enough to stagger the imagination of the boldest dreamer. The Anglo-Egyptian army at Omdurman opened an entirely new chapter in the history of the control of the Nile.

No one can hold Egypt securely unless he holds also the whole valley of the Nile. The sources of the river in hostile, or even in indifferent, lands must always be a grave cause of danger, or, at the best, anxiety. If tradition be correct, the Abyssinians on more than one occasion made use of their position on the Nile as a powerful lever in negotiations with Egypt. Vansleb, the Dutch seventeenth-century traveller already quoted,[6] is not perhaps perfectly trustworthy as to his facts, but at least he is evidence as to the tradition. He had in his possession, he says, a copy in Arabic of a letter written by David, King of Ethiopia (_i.e._, Abyssinia), surnamed Constantine, to ‘Abu Seid Barcuk, King of Egypt, in the year of martyrs 1193, in which he threatens in two distinct places to turn aside the river Nilus and hinder it from entering into Egypt,’ so as to cause all the inhabitants to perish with hunger, if he ‘continues to vex the Copties.’ Vansleb also says that ‘the King of Ethiopia hindered the current of Nilus and turned it out of Egypt in the days of Mostanser, one of the califfes of Egypt, which obliged him to send the Patriarch of the Copties with rich presents to the King of Ethiopia, to entreat him to take away the bank, which he had raised to turn aside the river. The King of Ethiopia having granted this request for the sake of the Patriarch, the river increased in one night 3 cubits, which was sufficient to water the fields.’ Doubtless the tradition is founded on fact; if the country in question had been occupied by a Power with any engineering skill, there is little doubt that this method of pressure would have been oftener adopted.

The danger is by no means an imaginary one, and this is recognised in the latest treaty between the Government of the Soudan and Abyssinia, concluded May 15, 1902, in which it is laid down that no work shall be constructed across the Blue Nile, Lake Tsana, or the river Sobat, which shall arrest the flow of their waters into the Nile, except by mutual agreement.

If even now it is thought necessary to make formal treaty arrangements on the subject with Abyssinia, much more real would be the apprehension if the Soudan Government were hostile to Egypt. But quite apart from any hostility, an important question might arise. We have seen what great efforts have been made in Egypt under the system of perennial irrigation to secure a good supply of water in the summer months; it is then that the river is at its lowest; the best of reservoirs can only supplement the natural flow of the river. At the very time that it would be easiest to do it, an interference with that natural flow would be most disastrous. The mere employment of a considerable amount of water on irrigation in the Soudan during the summer months might have a very serious effect. The possession of the Soudan practically guarantees to Egypt the safety of her water-supply. The fact that the sources of the White Nile are in purely British territory, and that in the Soudan itself the British flag flies side by side with the Egyptian, gives thus a more and more permanent aspect to the British position in Egypt.

It is calculated that at the present moment another 3,500,000,000 cubic metres of water over and above the present summer supply, including the Assouan Reservoir, would amply suffice for all possible requirements in Egypt. When the Dam is raised to its full height, about 1,000,000,000 cubic metres more will be provided. If only Egypt were to be considered, the remainder of the water required could be stored in a similar reservoir built somewhere above Wadi Halfa. Egypt could then be developed to its very fullest extent, but ‘such a work,’ as Sir W. Garstin remarks, ‘would leave untouched the countries bordering the river to the south. Their interests must be safeguarded by such a scheme as will insure them a proportional share in the prospective benefits.’

From every point of view the interests of the Soudan are vital to Egypt. Bitterly has she suffered from the neglect of those interests in the past. Misrule and oppression caused the Mahdi’s rebellion, with all its burden of shame and suffering. With a more intelligent enemy the loss of the control of the Nile might have meant irretrievable disaster. She knows now that a prosperous and contented Soudan is the best safeguard against rebellion. Upon England, too, rests the responsibility for the welfare of those vast provinces, once so shamefully abandoned to barbarism and ruin. English arms have retrieved that disgrace. It would be impossible to allow the Soudan to get nothing and Egypt everything, even if such a course were not certain to be fatal to both.

At present far-reaching schemes are being carefully inquired into, under the guidance of Sir W. Garstin. Fortunately for Egypt, she possesses in him an adviser of unsurpassed experience, cool, careful, and level-headed, upon whose final judgment she may confidently rely. He has already made a report, after personal observation, upon the White Nile and its main affluents, and he has recently returned from a journey to Lake Victoria Nyanza and Lakes Albert and Albert Edward, the results of which have not yet been published. Another expedition was also sent in 1902-1903 to explore Lake Tsana and the upper course of the Blue Nile. A mass of information is being collected and quietly digested, and in due time the policy to be pursued will be settled on. For the moment there is no occasion for hurrying. It will take time for Egypt to make full use of the advantages of the Assouan Reservoir. The Soudan, though rapidly progressing, is hardly yet in a position to reap the advantage of such changes on a great scale. When the engineers have completed their observations, there will still be the financial aspect of the question to take in hand. Schemes involving the regulation of 2,000 miles of river cannot be subjected to too great scrutiny before arriving at a decision. It would be rash to speculate on what course will be finally adopted, before all the data are known, but it will not be out of place to give some indication of the rival projects in view, and to glance at some of the arguments for and against.

All the schemes aim at establishing a control over the head-waters of the Blue or the White Nile, and so increasing the supply in the river when it is most scanty. Anyone can see that the Blue Nile depends upon Lake Tsana, which is across the Abyssinian frontier, and the White Nile upon the Lakes Victoria and Albert Nyanza. Proposals have been made for regulating the outflow from each of these lakes, or from them all, and also for preventing the waste of water which now takes place in the swamp country south of Fashoda. Up till now the plan of building a dam at the point where the Blue Nile emerges from Lake Tsana has been most in favour.

It has several great advantages. This lonely lake is situated some 6,000 feet above sea-level, in a wild and desolate country in Northern Abyssinia. It is 3,300 square kilometers in extent, and very deep. During six months in the year there are very heavy rains in the area which drains into the lake. Between Lake Tsana and Khartoum, a distance of 1,350 kilometres, the Blue Nile falls over 1,000 metres, and its rocky bed makes it very suitable as a channel for carrying the water. It is deep and narrow, with high, steep banks, and so the less liable to evaporation. For every metre by which the level of the lake was raised, 3,300,000,000 cubic metres would be stored, and it is obvious that, if the level were raised 4 or 5 metres, there would, after making a proper deduction for evaporation, be ample water to supply the greatest demand in Egypt, and also plenty besides available in the Soudan. There are also strong arguments for irrigation works on the Blue Nile. After the Cataracts of Rosaires, which are roughly speaking about halfway between Khartoum and Lake Tsana, the river passes through fertile plains consisting of rich alluvial soil, extending to a great distance on both sides. At present these lands yield only small returns, dependent as they are upon a somewhat capricious rainfall. With proper irrigation they would be most productive, and the water coming down from Tsana might be utilized, without any great difficulties, by a system of canals starting from this point, assisted by barrages and weirs. Further, the river would thus be rendered navigable at all seasons of the year, and would thus become an effective trade route in the most promising part of the Soudan. The great objection is that Lake Tsana lies wholly within Abyssinian territory. Nothing could be done without some very definite arrangement with the Emperor Menelik, and one that would be irrevocable by any successor of his who might be less friendlily disposed. Nothing, in fact, would be absolutely satisfactory unless complete sovereignty over the Reservoir district were assured to the Soudan Government. In view of the fact that the whole of this region is perfectly valueless to Abyssinia, or, indeed, to anybody else, except for purposes of water-storage, it does not seem impossible that by some cession of territory, or other compensation elsewhere, a satisfactory arrangement may be come to. But even so, the remoteness of the lake and the difficulties of transport would prevent the immediate realization of the scheme. Without a railway from some point in the Nile Valley it would be practicably impossible to collect the necessary materials and supplies, and such a railway will not be an affair of this year or next.

Precisely on the points where the Lake Tsana scheme is weakest the schemes for utilizing one or both of the great lakes of Uganda are strongest. Precisely where it is strong they are weakest. Any works damming the exits of Lake Victoria Nyanza or Lake Albert would be wholly within British territory. They would also be in a region much more easily accessible from the sea. Lake Victoria has already railway communication with Mombasa, and the transport of material, and also of coolie labour from India would be comparatively easy. In the case of Lake Albert, a railway would have to be built from Lake Victoria; but this would be of service to the country apart from any irrigation works, and would, indeed, practically establish through communication by boat and railway between Mombasa and Alexandria. But here their advantages over Lake Tsana end. The whole region is very much subject to earthquakes. The strain to which great masonry works would be subjected might be very severe. The country through which the White Nile passes is very unsuited to large irrigation works. Much of it is swamp, and the low slope of the land is ill-adapted for canals. The soil, too, is poor and light compared with the rich alluvial tracts on the Blue Nile, which would of course receive no benefit. Practically only the provinces north of Khartoum would receive any benefit from the increased supply, and in them the cultivable land can never be more than a mere strip along the river, so circumscribed are they by the desert ridges. In any case they would be equally benefited by water coming from the Blue Nile. Besides this, the negro population living on the White Nile is very much less advanced, and less likely to form an industrious agricultural population than the inhabitants of the Eastern Soudan.

Nor is the bed of the White Nile well adapted for carrying the water. From Lake Albert to Khartoum the distance is 2,100 kilometres, and the total drop is only 300 metres. It flows slower through a hotter country. Except between Duffile and Rejaf it is very wide and shallow, without any banks to speak of, and with a sandy or muddy bottom. For at least half its course it runs through swamps, and between Bor and Lake No alone it is calculated to lose half its volume by dissipation and evaporation in the marshes. But for the important contribution made by the Sobat, the volume reaching Khartoum would be very much smaller than it is. If, then, a considerable extra supply of water is to be brought down from the equatorial lakes, the scheme must involve a permanent improvement in the channel of the Bahr el Gebel, as the upper portion of the White Nile is called.

This, according to Sir W. Garstin, can only be effected in one way, by embanking the river for its whole length between Bor and Lake No, a distance of 624 kilometres. When it is considered that all supplies would have to be brought from Khartoum, 1,000 kilometres distant; that during four months of the year work is impossible, owing to the incessant rains; that the local tribes can never be relied upon for labour; that the climate is exceedingly bad and unhealthy at all seasons; and that the actual engineering difficulties in making the banks would be by no means small, some idea may be formed of the cost of such an undertaking. It is estimated that to complete it in five years’ time would involve an expenditure of £3,700,000. Another proposal, which is really independent of the Reservoir question, is to use the Bahr el Zeraf to carry the extra summer supply at present wasted in the marshes. The Bahr el Zeraf is a branch of the Nile, taking off near Shambe, and entering the river again below Lake No before the junction of the Sobat. The cost of preparing the Bahr el Zeraf channel by means of dredging and embanking is estimated at £1,250,000, and in addition certain supplementary works would be required.

Until the result of Sir W. Garstin’s observations on the Albert Lake are known, it will be impossible to make any accurate comparison of the qualifications of the two lakes Victoria and Albert for being utilized as reservoirs. Lake Victoria, which lies between the two ‘Rift Valleys,’ is encircled by a low and shelving shore. It covers approximately about 70,000 square kilometres. The Somerset Nile flows out of it, and finds its way into Lake Albert. Lake Albert is the northernmost of the chain of lakes in the western Rift Valley, and into it drains the Albert Edward Lake by means of the Semliki River, partly fed by the glaciers of Mount Ruwenzori. The Nile issues from it at the northern end, not so very far from where the Somerset Nile enters. Lake Albert is surrounded by mountains and cliffs. There is comparatively little flat shore round it. Its area is roughly about 5,000 square kilometres. For every metre that the surface of each lake was raised, Lake Victoria would store 70,000,000,000 cubic metres, and Lake Albert 5,000,000,000. These enormous figures are enough to show that, even when the largest allowance has been made for loss by evaporation, dams of no great height on either lake would suffice to store quite sufficient water for all possible needs in Egypt, and all of the Soudan that could be touched by water coming down the White Nile.

A very small rise in the level of Lake Victoria would give a very large reserve of water, and therefore the works regulating its outflow would be of less dimensions, and so, presumably, less subject to damage by earthquakes. Being nearer the sea, they would, moreover, be easier of construction. But Sir W. Garstin so far totally rejects the idea of Lake Victoria. He says:

‘The amount of water which could be stored even by a very small rise in the levels would be far beyond any possible requirements. This lake may consequently be omitted altogether from any projects for water-storage. Much of the country adjoining Lake Victoria Nyanza is densely populated, and the villages are situated close to the shores. Any considerable rise in the water-levels would flood a large and populous area of country. It must not, moreover, be forgotten that about half the area covered by this lake falls within German territory. As the inhabitants of the southern half of this lake would derive no benefit from such a reservoir, it is quite conceivable that they might view any such proposal with disfavour.’

He proceeds to argue that Lake Albert, on the other hand, is specially adapted by its conformation for the purpose.

‘With a regulating dam at a point on the river below its exit, the Albert Lake could well be used to store up water during the rainy season, which would be discharged into the river during the months of low supply. In this way a double purpose would be served: the volume of the river in flood would be diminished, and in summer would be largely increased. The lake has an enormous catchment area, and it seems probable that its levels could be, without serious difficulty, raised to the required height.’

In all probability the arguments will be found to be conclusive in favour of a dam at the exit to Lake Albert, but the reasoning against a regulator for Lake Victoria does not appear at first sight very cogent. Sir W. Garstin tells us that three years ago the mean water level of the lake averaged some 8 feet lower than it did twenty years earlier. But between January 1 and June 1, 1901, the level rose 3 feet 3 inches. When such fluctuations already occur in the ordinary course of Nature, it would seem that some very useful regulation might be carried out without causing the least inconvenience to any dwellers on the shore, German or otherwise. All these remarks, however, were written quite tentatively by Sir W. Garstin before he had personally examined these regions, and his next report will be certain to give fuller information on the matter. Perhaps in the end both lakes will be subjected to the yoke of the engineers.

Such in brief outline are the gigantic schemes which are now engaging the attention of the irrigation authorities of Egypt. Great as are the achievements of the past, they look almost petty before these visions of the future.