Chapter V: The Delta Barrage and the English Engineers

At the date of the English occupation the Delta Barrage was generally thought to be like the whole fabric of Egyptian Government, rotten to the core. And so indeed it seemed. No one had ever dared to use, or apparently even to think of using, the Barrage on the Damietta or right-hand branch at all. The history of the Barrage on the Rosetta branch was hardly less inglorious. In 1863 its gates were closed for the first time, but about ten of its arches began to settle, and ominous cracks showed. Eventually the threatened part was surrounded by a coffer-dam, and from 1872 to 1883 it managed to hold up about 1 metre. But even that was precarious. Commission after Commission had condemned the structure; it was felt that at any moment it might give way, especially if called upon to bear a greater strain, and it was actually the settled policy of the Government to rely on huge and costly pumping-stations instead. It was a paltry result after the expenditure of £4,000,000 and so much labour.

Then, not for the first or last time, the Anglo-Indians came to the rescue of Africa. Sir Evelyn Baring himself (now Lord Cromer) during his service as Financial Member of the Council in India, must have been impressed by the enormous importance of irrigation. It would not be difficult to find many points of resemblance between his character and that of one of the greatest, if not the greatest, of the rulers of India, Lord Lawrence, different as were their spheres of work; but certainly they were alike in this. As Lord Lawrence supported Arthur Cotton in his engineering work, so Lord Cromer supported Colin Scott-Moncrieff and the band of trusty lieutenants—Willcocks, Garstin, Ross, Brown, Foster, Western, and Reid—who came with him. Fortunately for Egypt, these men, trained in the best school of irrigation in the world, possessed not only the highest scientific skill and knowledge, but were also animated by the best spirit of the empire-building Englishman. Deep in them lay the earnest wish and determination, far stronger even than their enthusiasm and love for their profession, to alleviate the lot of the unhappy peasantry of Egypt. It was this heartfelt sympathy for the wrongs of the fellaheen, ground down by the intolerable burden of the corvée, that sustained them in their ceaseless labours and enabled them to pass successfully through those dark days, when the air was full of forebodings of failure and disaster, whose fulfilment would have pleased so many.

The Barrage is situated, as has been said, a little way back from the point of the Delta. It is really two Barrages, one on the left or Rosetta branch of the Nile, with sixty-one arches, 465 metres in length, and the other on the Damietta branch with seventy-one arches, 535 metres in length. Between the two runs a revetment wall across the intervening tongue of land, 1,000 metres in length. From a distance it resembles a bridge of rather fanciful design, with the arches set unusually close together, and, indeed, for a great part of its career the functions of a bridge were the only ones it performed. The tongue of land between has been converted into beautiful gardens, planted with shady trees and many shrubs and flowers, and even a greensward resembling grass. Altogether, it is one of the most delightful and beautiful spots in Egypt, besides being one of the most useful. Here is the starting-point of the great feeder canals which irrigate the Delta provinces. On the left, facing north, is the Rayah Behera, which supplies the province of Behera, to the left of the Rosetta branch. Between the two Barrages is the head of the Rayah Menoufia, the canal which feeds the two provinces of Menoufia and Gharbia, lying between the two arms of the river; while on the right is the Rayah Tewfiki, which, with its supplementary canals, Ismailia, Sharkia, and Basusia, supplies the three eastern provinces of the Delta, Kalyubia, Sharkia, and Dakalia. All these canals are navigable, as well as the branches of the river, and provided with locks for that purpose. These great waterways are free to all, and few of the results of British occupation are more appreciated in Egypt. Formerly all craft upon the Nile had to pay toll on passing under a bridge, which did nothing but hinder their progress, while those for whose convenience it was made passed without charge overhead.

A Barrage, as its name implies, is designed to completely bar the bed of the river, so as to enable it to feed the canals at a higher level than would otherwise be the case, and also to allow the flood to pass through it easily. It needs, therefore, a very solid foundation from bank to bank, on which the arches which hold the movable sluice-gates can be securely planted. Its construction is, therefore, a very different and much more difficult matter than merely throwing a bridge over the stream, even a bridge with several spans. The difficulty is all the greater when, as here, the bed of the river offers nothing more substantial than shifting sands to build upon. It was for this reason that Linant wished to build the Barrages at leisure in the dry, and then divert the river from its old channels, and lead it through when they were completed. But Mougel chose to build his in the existing bed of the river, thereby increasing the difficulties of actual construction, though from other points of view there was much to be said for this plan. At the site of the Rosetta Barrage the bed of the river was not of uniform depth; he therefore filled up the deepest part of the channel, which lay on the right, with loose stones, so as to bring it up to the level of the bottom on the left-hand side. No cement was used in laying down this barrier, but the Nile mud filled the interstices and made it water-tight; when finished, this barrier was 60 metres wide and 10 deep at the deepest part. On this and on the natural sand he built a platform 46 metres in width and 3·5 metres thick, composed of concrete overlaid with brick and stonework. On the platform he raised his arches and piers, all built of brick. Each of the openings for the sluice-gates, sixty-one in number, was 5 metres wide. Like an iceberg, that part of the Barrage which is visible above water is much less than the invisible part below. To further strengthen the structure and keep it in its place, a mass of rubble pitching or loose stones was thrown into the river on the downstream side. This talus was 3 to 16 metres in depth, and at one part extended 50 metres downstream in a kind of tongue, narrowing down to 2 metres. The Damietta Barrage was built on a similar plan, but its downstream talus was not so large. Unfortunately, the concrete used for the platform was inferior, chiefly owing to the fact that Mehemet Ali, growing impatient at the slow progress of the work, ordered a certain amount of material to be laid down every day, and laid down it had to be in defiance of all engineering requirements. The consequence was that, as soon as the Rosetta Barrage was subjected to strain, ten of the arches on the left-hand side, where the platform was laid down on sand only, settled and cracked. It was patched up by surrounding the injured arches with a coffer-dam; but the Damietta Barrage never even had its gates put in.

Such was the structure with which the English engineers had to deal. Even as it stands to-day, it cannot, of course, compare in magnitude with many works upon the Indian rivers; but as regards the difficulties to be overcome, it can compare with almost any in the world. It would have been far easier to rebuild the whole thing from the beginning, but at the time the necessary funds were not forthcoming. They had to take the old structure, with all its imperfections, and screw it up to work as it was. The country could not afford to cut off the summer water-supply of the Delta while the repairs were in progress. The cotton-crop had always to be thought of. And the period of the year during which the summer canals required to be supplied was the only period during which work could be done, for once the flood came down all operations were at an end. It is the glory of the English engineers that, working under these conditions and with untrained workmen, they succeeded in their task.

The Government was already paying many thousands a year to a company for pumping water out of the Rosetta branch into the canals during the summer, and the first thing Sir Colin Scott Moncrieff had to do on his arrival was to decide upon a scheme which had been prepared for erecting new pumping-stations at an initial expense of about three-quarters of a million, and involving an annual expenditure of at least another quarter of a million. So hopeless were the prospects of the Barrage assumed to be, that even this expenditure, with a doubtful result, was thought preferable to repairing it. Sir Colin’s arrival was only in the nick of time. He determined to see what could be done with the resources at hand. The new pumping-station scheme was set aside, and Mr. Willcocks was put in charge of the Barrage.

There was much literature on the subject. During the last sixteen years nothing had been done, but much had been written, and more said. Commissions, expert and inexpert, had issued voluminous and condemnatory reports, and had even prepared expensive schemes of repair. Mr. Willcocks (now Sir William) is an indefatigable reader, and could hardly have been encouraged thereby, till an examination of the structure itself showed that all the later reports had been drawn up without reference to facts. It had been observed that whenever the gates were let down there was very severe action of the water on the downstream side. The authors of the reports concluded that the foundations were honeycombed. It is characteristic of the Looking-glass days of Ismail that no one ever thought of trying to find out by actual observation whether there might not be some other cause. But Mr. Willcocks, looking for himself, found that this action of the water was caused, not by honeycombed foundations, but by open gratings which intervened between the bottom of the sluice-gates and the platform. They had been put down originally to keep the silt away from the bottom of the gates. Someone had fixed them so as to prevent the gates from being lowered to their full extent and then they had actually been forgotten. Measures were at once taken to close these gratings, and eventually to remove them altogether. 20,000 cubic metres of rubble pitching were added to the talus. The Damietta Barrage was likewise strengthened with various ingenious expedients, improvised to meet the demands of the moment. Sluice-gates were put in for the first time and gradually closed. Part of it was closed by a temporary stone dam. Eventually in the summer of 1884 2·2 metres of water were held up on the Rosetta branch, and 1 metre on the Damietta. Next year the same nursing process was continued. The coffer-dam round the weak arches was strengthened, the talus of rubble pitching below each Barrage was completed, and this year 3 metres were held up on the Rosetta branch and 1·6 on the Damietta. The effect was extraordinary. The acreage under summer cultivation was doubled, rising from 600,000 to 1,200,000 acres. Not only was the supply of water in the Delta canals greatly increased throughout the summer, but, as it was delivered at a higher level, there was a great saving of expense in lifting it on to the land. For the first time the Egyptians thoroughly realized that a new power had come amongst them.

The experiment had been successful, but temporary expedients could not last for ever. The more water held up, and the greater the area of the summer cultivation, the more necessary it became to insure the stability of the structure. A thorough repair would cost money. Fortunately, this was now forthcoming. Mr. Willcocks’ success had settled the claim of the Barrage to a share in the famous Irrigation Million borrowed in 1885.

At the end of 1886 the work was begun, under the charge of Colonel Western and Mr. Reid, sent specially from India for the purpose. The operations were spread over four years. In the first year the left half of the Rosetta Barrage was taken in hand and finished before the flood, next year the right half. In 1889 and 1890 the Damietta Barrage was similarly taken in hand and finished. Each year the part to be repaired was enclosed by earthen dams, and the water pumped out so as to lay the foundations dry. The whole of the existing floor was raised, both on the upstream and downstream side, and it was also considerably lengthened. It was, in fact, enclosed in a new and reliable suit of armour. The dangers and anxieties of the work were incessant. The protecting dams were always liable to be breached. Spring after spring burst out through the treacherous bed of the river, and threatened the destruction of the year’s work; and again and again each of them was successively stopped by a number of ingenious devices. There is no enemy so persistent and so insidious in its attacks as running water. It is always feeling for and finding out the weak spots. It never sleeps or slackens by day or by night. It can only be met successfully by a corresponding activity. While work was possible, it was carried on unceasingly by night as well as by day. Sometimes as many as 1,600 men worked through the night. The upper brickwork was generally sound, but new iron sluice-gates moving in special grooves were fitted throughout. The whole of the repairs cost £465,000. It was money well laid out. Not only was the safety of the Barrage assured, but it was found possible to hold up yet another metre of water. The area of summer crops matured rose once more from 1,200,000 to 1,520,000.

It might have been thought that the work was now complete. Both in 1891 and 1892 (a year of specially low summer supply) all the water in the Nile was held up, and diverted into the canals. Not a drop reached the sea during the summer without having done duty. But the engineers were now looking forward to a time when the supply would be greatly increased. The idea of a reservoir had become an affair of practical politics. It was necessary to make assurance doubly sure. Accordingly, in 1896 a new experiment was tried—namely, stock-ramming with clay.

Certain arches in the Damietta Barrage were selected, and in them five-inch holes were bored right down through pier and platform alike. When the bore-holes were complete, they were lined with iron tubes. Clay was then forced through the tube by means of an iron rammer, and as much as could be made to spread out at the bottom of the hole was put in and rammed. As far as the clay went, the experiment was not an entire success; but the boring brought to light a condition of things in the very vitals of the Barrage which demanded drastic treatment, for the bore-holes proved the existence of large cavities in the original platform, and in some places there was free water communication between one bore-hole and another. Some piers in the Rosetta Barrage were therefore chosen for a similar experiment, but this time liquid Portland cement was used instead of clay, and the results were entirely satisfactory. Few discoveries have been of more signal service than the invention of Portland cement. It is not too much to say that it has revolutionized hydraulic engineering by the facilities it affords for constructing solid works in water. Its strength and resisting power is enormous, but its greatest quality is that it hardens and solidifies under the action of water, and, so far as is known, only goes on getting harder and harder with time. The borings in the Rosetta Barrage having revealed similar deficiencies to those in the Damietta, it was decided to apply to both a thorough dose of this invaluable and invigorating medicine.

In 1897 five holes were bored in each pier of the Rosetta Barrage (their united length amounted to very nearly 6 kilometres), and into each was poured a quantity of liquid cement. The necessity for the treatment was proved by the fact that in some cases the cement travelled right through from the bore-hole in one pier and rose through the bore-hole in an adjoining pier till it reached the top. One pier actually swallowed 439 barrels of cement, while its neighbour took a lesser but still gigantic draught of 327 barrels. There was no doubt that the cement thoroughly explored and filled all the cavities existing in the foundations under the bridge. In all, 3,254 barrels were used in the Rosetta Barrage alone. In 1898 the grouting process, as it is called, was applied with equal success to the Damietta Barrage.

To use Sir Hanbury Brown’s homely but expressive image, the process applied to the Barrage was exactly that followed by a cook who wishes to finish off a cold pie with its proper complement of jelly. The jelly is introduced into the pie in the form of warm gravy, which penetrates into and fills every recess of the succulent interior, and then solidifies as it cools.

And still the engineers were not satisfied. So treacherous is the river’s bed that no possible safeguards seemed superfluous. It speaks volumes for the courage and skill of those who in 1885 held up 3 metres of water with the old unreformed Barrage, that in 1897, after the successful execution of such great and costly repairs, it was still thought advisable to undertake completely new works to assist in the task of holding up 4, or at the most 5, metres.

It is a principle in hydraulics, not easily understood at first by the layman, that the pressure upon a weir or barrage in a river depends entirely upon the difference in level between the water on the upstream and on the downstream side, and not on the mere volume of water in the river behind it. In December, 1897, the Caisse de la Dette voted £530,000 for the construction of two subsidiary downstream weirs, with the object of relieving the pressure on the Barrage by raising the level of the water on the downstream side, thus dividing the head of water to be held up into two—in other words, by making two steps instead of one. Each weir was to consist of a core of rubble masonry set in cement, sunk well below the bed of the river, and protected up and down stream by a long slope of rough stone blocks or pitching. To make the masonry core thoroughly watertight, a mass of clay puddle was to be put on either side of it. The weirs were thus to be a solid dam, blocking the course of the stream up to such a height that the head of water on the Barrage, at that time amounting to 4 metres, would be reduced to 2·5 metres. The flood would pass freely over the top of the weirs. At the same time the sluice-gates of the existing Barrage were to be heightened, so as to permit the upstream level to be raised 1 metre more in June and July, so as to take full advantage of the rising flood and facilitate the early sowing of maize, a great point with the Egyptian cultivator.

By the summer of 1900 this programme had been completed. The building of the weir on the Rosetta branch was an especially fine performance, for which great credit was due to Sir Hanbury Brown and Mr. Brooke, who were in charge of it. Five hundred metres in length, it was begun at the end of December, 1899, and actually finished before the flood began to come down in July. The same Portland cement played a great part in its construction. It may now fairly be said that the Barrage is complete at last, and fully equal to every strain that it can be called upon to bear.

The weirs were constructed not a moment too soon. It so happened that the summer supply of 1900 was lower than in any previous year of which records have been kept. In 1889 the river sank to a level of ·60 metre below zero on the Assouan gauge. In 1878 it fell to ·71 metre below zero, and this was the lowest known before the summer of 1900. But on three days in that year, May 15, 16, and 26, the river fell to a level of ·91 metre below zero. The position was aggravated by the extension of summer cultivation. The total extent of summer crops had risen still further to over 1,700,000 acres.

To save the valuable cotton crop was the earnest preoccupation of the Irrigation Department. They were able by the most strenuous efforts, not merely to save the crop, but so to treat it that it gave a yield which, only a few years before, would have been considered perfectly impossible even in a good year. But all their efforts would have been in vain had it not been possible, thanks to the new weirs, to raise the level of the water upstream of the Barrage to an extent which would have been exceedingly dangerous without their assistance, and so to take full advantage of the rising flood. The mere enumeration of the special measures which were put into force gives a very good idea of the difficult duties which devolve on those who control the water in Egypt:

1. Earthen dams were constructed in both branches of the river to prevent the inrush of salt water from the sea.

2. Special programmes were laid down for ‘rotations’ on the canals.

The system of rotations, which was introduced from India, is that the land-owners are only allowed to pump water on to their lands at certain intervals. There are several advantages in this. The water is economized, and as it can thereby be kept at a lower level in the canals, there is less danger of the soil becoming deteriorated by excessive saturation. The pumps are allowed to work for a certain period, according to the district, and then an interval is prescribed, until the expiration of which they are not allowed to work again. In 1900 the pumps were allowed to work for a period of six days at a time, and at first twelve days was the interval until the next pumping. But as the summer wore on, and the river continued to fall, the interval was gradually extended to twenty-two days—a very severe measure indeed.

3. All land-owners were warned not to sow rice.

4. They were also forbidden to sow maize until a date should be announced.

5. Special pumping arrangements were made.

6. There was more than usually careful regulation at the heads of the canals above the Barrage, so as to insure a proper distribution of the water available to all the provinces.

7. A special staff was appointed to see that all these regulations were carried out.

Could any government be more paternal than this—it might even be said, more despotic? But countries which depend on irrigation have a natural tendency towards despotism. When water is plentiful they may be as republican and democratic as you please; but when the crisis of scanty water comes they must have a strong hand over them, just as the Roman Republic had to have its Dictator in times of national peril. It speaks well for the good sense of the Egyptians, and it proves their implicit faith, built up by sixteen years’ experience, in the English engineers, that even those stringent regulations were unhesitatingly obeyed, and that breaches of them were so rare as to be almost non-existent. They had their reward; for while 1878 is still remembered as a year of black disaster and distress, in 1900 the cotton crop amounted to no less than 5,250,000 kantars,[5] and the maize crop, in spite of its late sowing, was also very good. Only the rice, a comparatively insignificant item, was sacrificed to its more important rivals. Thanks mainly to the good work done by the completed Barrage, neither the public nor the private finances of Egypt suffered the least shock from a year of unprecedented scarcity of water, even when this was coupled with most unseasonable cold and fogs in September, which considerably diminished the output of cotton. Lord Cromer had indeed good reason to write in 1901:

‘Had it not been for the labours of the eminent hydraulic engineers, who for the last seventeen years have placed their services at the disposal of the Egyptian Government, the most skilful financial assistance would not have availed both to place the Egyptian Treasury in a position of assured solvency and to meet in any adequate degree the constant demands which are the necessary accompaniment of a policy of reform.’

Such are the outlines of the long history of the Barrage, designed by Frenchmen and brought to perfection by Englishmen. Both nations can share in the credit of the work, and it is pleasant to record once more the generous and graceful act by which the chief of the English engineers recognised and acknowledged the merits of his predecessor. Sir Colin Scott Moncrieff discovered Mougel Bey living in obscurity and oblivion, weighed down by poverty and neglect. It was owing to his intercession that the poor old man was rescued from want, and, by means of a pension granted by the Egyptian Government, enabled to spend his remaining days in comfort and honour. Both nations are entitled to be proud of this act of poetic justice, which added a lustre of its own to the glory of the completed Barrage.