Prehistory
Throughout the prehistoric period and
then through history, communities have been
familiar with the element and elemental force of water. They have sought it out,
striven with it, worshipped it, and, with the aid of technology, tamed it. This struggle
against wetlands, bulking so large in the story of all peoples and all lands, has
reached its climax in the building of audacious works to control rivers and drain
valleys.
For thousands of millions of years water
has been shaping the face of the earth,
and for more than one thousand million it has sustained plant and animal life. In
comparison, our appearance dates back less than a million years, and we
achieved a breathtaking ascendancy in a moment of geological time. We has
succeeded in imposing a measure of control upon the elemental forces, altering
permanently the face of the globe. Our great hydraulic undertakings are symbols of
all the cyclopean structures made by the technocrats of all the ages. Just like the
Tower of Babel, the Pyramids, the Chinese Wall, the temples and cathedrals and
palaces of the different civilizations, his barrages and dikes are the most recent
expression of a very ancient dream of humanity: to achieve the everlasting.
The legendary Emperor Yti, whose reign
is assigned by the Chinese chronicles to
as early as 4,300 years ago, said: 'Nine rivers have I led unto the ocean and I have
brought all the ditches to these rivers.' It is significant that the Chinese should have
made Yii, the most important of their early rulers, a water engineer, a man who, if
the chronicle is to be trusted, vanquished the Hwang-Ho, that destroyer and
scourge of China. The dikes built under Yii held firm until the seventh century A.D.,
when the Hwang-Ho abruptly changed its course.
It has been said of the Chinese that they
can move mountains with wheelbarrows,
and it is a fact that over two thousand years ago, by mobilizing hundreds of
thousands of men and without the use of machinery, they succeeded in building
reservoirs and an extensive network of canals and ditches. Their methods were
scarcely different from those employed in recent years to subdue the rivers. At
times there have been ten million men and women, often provided only with
barrows and baskets, working at the enormous barrages and embankments which
have been rising since 1950 in many parts of the great river valleys. The Great Wall
is no longer the most representative monument of China: primacy must now be
given to the hydraulic system of the Yangtze-kiang. By bringing its watercourse
under control China expects to increase her electric power tenfold, to multiply by
seven the extent of her arable land, and thus to save the lives of millions who would
otherwise fall victim to famine or flood, as has often happened in the history of that
country.
When describing the seven wonders of the
world in 250 B.C. Philo of Byzantium
included among them the hanging gardens of Semiramis at Babylon. But when
compared with the hanging gardens and terraced plots of the Indians of Central and
South America the gardens of Semiramis begin to lose their glamour. The Indian
civilizations prior to the time of Columbus created irrigation systems of superlative
scope and perfection. In the twelfth century, according to the Spanish chronicler
Sarmiento de Gamboa, writing in 1572:
Pachacuti
Inca Yupanqui, considering the small extent of land round
Cuzco suited for cultivation, supplied by art what was wanting in nature.
Along the skirts of the hills near villages, and also in other parts, he
constructed very long terraces of 200 paces more or less, and 20 to 30
wide, faced with masonry, and filled with earth, much of it brought from a
distance. ... He ordered that they should be sown, and in this way he made
a vast increase in the cultivated land, and in provision for sustaining the
companies and garrisons.
It is clear that the Incas were already
familiar with such techniques and with artificial
means of irrigation, for Sarmiento also says that the eleventh-century Inca Rocca:
.
. . discovered the waters of Hurin-chacan and those of Hanan-chacan,
which is as much as to say the upper and lower waters of Cuzco, and led
them in conduits; so that to this day they irrigate fields; and his sons and
descendants have benefited by them to this day.
Sir Clements Markham, who was among the
first to rediscover the civilization of the
Incas, in 1852-53 travelled extensively in Peru. He wrote of the Nasca Valley:
The
whole of this space is covered with rich and fertile haciendas, yielding
large crops . . . ; yet, all that nature has provided for the irrigation of this
lovely valley, is a small watercourse, which is dry for eleven months out of
the twelve.
But,
in former days, before the arrival of the destroying Spaniards, the
engineering skill of the Incas had contended with the arid obstacles of
nature, and, by executing a work almost unequalled in the history of
irrigation, the wilderness of Nasca was converted into a smiling paradise.
This
was effected by cutting deep trenches along the whole length of the
valley, and so far up into the mountains, that to this day the inhabitants
know not to what distances they are carried.
High
up the valley are the main trenches, called, in the language of the
Incas, puquios. They are some four feet in height, with the sides and roof
lined with stones. As they descend, they separate into smaller puquios,
which ramify in every direction over the valley, supplying each estate with
the most delicious water, and feeding the little streams that irrigate and
fertilize the soil.
The
main trenches are many feet below the surface, and at intervals of
about two hundred yards there are ojos, or small holes, by which workmen
may go down into the vault and clear away any obstruction. The puquios
diverge in every direction, some of them crossing over others, and, before
they reach the termination of cultivation towards the south, all the water has
been exhausted on the various estates. There are fifteen vine and cotton
estates watered by this means in the vale of Nasca.
The European educated in the classical
tradition is apt to look down upon the
ancient civilizations of the Americas, but from there have come about a hundred
cultivated plants, of which many, such as potatoes, maize, tomatoes, cocoa and
rubber, now form part of his staple diet or serve to make objects of everyday use.
So thoroughly, however, did the Spaniards destroy the irrigation systems and
terraced fields where these plants were first cultivated that they have never been
rebuilt.
The Netherlands
In Europe in prehistoric times people
living on the North Sea coasts learned to build
primitive dikes against the encroachments of the sea and to erect their dwellings on
artificial mounds reinforced with stakes. The Romans, with their more advanced
engineering skills, developed a system of dikes to protect the Netherlands and
improved many waterways to aid the rapid transport of troops to the Empire's
frontiers.
In the Notebooks of Leonardo da Vinci,
that universal genius, are several hundred
references to water, and sound advice which has not always been followed by later
engineers:
The
straighter the course of a river, the swifter its current and the greater the
erosion of its banks. To prevent this, the beds of such rivers should be
widened, or their waters must be made to follow a winding course or be
divided into branches. But if a river with many meanders becomes sluggish
and marshy, its course should be straightened to an extent which gives its
waters sufficient movement but does not lead to the undermining of the
embankments.
Of Leonardo's many plans for the building
of canals, the diversion of rivers and the
draining of marshes, few were realized in his own time.
At all periods sphagnum moss has been
dried and used as fuel in areas devoid of
timber, but it was not until the thirteenth and fourteenth centuries that a small
country, poor in wood but rich in bog, marsh and lake, revealed to the world a large-
scale technique of peat-cutting and its possible results. The Netherlands, formed
very largely of river deltas, has much low-lying land and from remote times the
coastal areas have been constantly threatened by the sea. From the twelfth to the
fifteenth century the Dutch lost in this way one fifth of their territory. At all times the
Dutch have been forced to struggle obstinately in order to conquer and then to hold
their fields. Thus they achieved a rare mastery of agriculture, horticulture and the
regeneration of waterlogged ground. They defended themselves by building dikes
and embankments and by digging canals to facilitate the outflow of salt or brackish
water, so injurious to cultivation. The water was raised by pumps worked by hand
and then, from the seventeenth century, by the windmills whose outlines have
become a part of the landscape. The Dutch took advantage also of their
'amphibian' situation, and became a nation of fishermen, sailors and traders. And
as the resources of their country were limited, despite such efforts, they sought in
the East and West Indies the riches which Holland could not provide.
But those measures did not suffice to
replace the agricultural land lost to the sea,
and so the peasants looked toward the moors. They cut the turf and sold it to the
townsfolk for fuel, thereby increasing the danger; for the trenches and pits filled and
created new stretches of standing water which could not drain away.
In the north-east they grappled with the
problem differently. The floods of 1287 had
claimed 50,000 victims in the area between the mouth of the Ems and the Zuider
Zee; those of 1421 twice as many. So two centuries before Dutch overseas trade
and colonization reached their zenith the people of Groningen 'occupied' their
neighbouring wastelands. They excavated canals allowing ships access to the peat
bogs, and as they had no desire to create new lakes and ponds but wanted, on the
contrary, agricultural land, they linked together the extraction of the peat, land
drainage and the growing of crops. First they made an intricate canal system, after
which they could take up the peat without causing the trenches to fill with water.
Then, when the layer of peat had been removed, the ground was divided among the
settlers—with the obligation to develop it. The rules were strict: nothing might be
burned, and it was compulsory to till and manure the soil, to keep the canals and
runnels clean, and to plant hedges and trees as wind-breaks. The general adoption
of such methods gradually changed the face of Holland.
The example of Groningen was copied by
other districts with peat bogs to exploit.
Villages grew up in the newly fertile areas. Sale of the turf provided the settlers with
the capital needed for increasing the network of canals; ships plied upon the
watercourses, fetching manures and taking away the dried peat and the produce of
the harvests. The success stimulated similar undertakings in other districts.
The achievements of Dutch engineers in
reclaiming their inundated coastal areas
need no emphasis. But it is easy to forget that many of the prosperous, clean,
attractive Dutch towns and villages, the green pasture lands with their cattle, the
fields of tulips, the bright parks, have been largely won back from the former
marshes. Rehabilitation of the waterlogged soil made the fortune of this little country
which has fought so valiantly and successfully against the encroachment of river and
sea.
Britain
In water engineering the palm must go
to the Netherlands. From the Middle Ages,
wherever a scheme for land drainage and reclamation or the building of dikes and
embankments was proposed, Dutch engineers were in demand.
One of them was Cornelius Vermuyden, who
arrived in England in 1621 to carry out
work on the Thames embankments and at Windsor. Next he undertook to reclaim
drowned land in Royal Hatfield Chase in Yorkshire. Part of his scheme was
unsuccessful and resulted in the flooding of an area to the north-west of Hatfield
Chase, which in turn gave rise to riots by the local population and attacks on the
Dutch and Flemish workmen he had engaged. Nevertheless, Vermuyden retained
the confidence of Charles I, who knighted him in 1629.
Accordingly in that same year, when proposals
were made for large-scale
reclamation of land in the Great Level of the Fens, an area of about 700,000 acres,
in spite of a general outcry against the further employment of foreigners it was soon
discovered that the only man capable of planning this enterprise was Vermuyden.
Haphazard and piecemeal drainage of England's fenlands had been attempted for
hundreds of years; but since the Reformation the older ditches and embankments
formerly maintained by monastic establishments had been neglected, and the new
landowners commanded neither the resources nor the skill to carry out more than
local improvements. The new works put in hand soon encountered active
opposition from the fenmen who, although they led a miserable existence in their
watery environment, living on fish and wild fowl, could see in its conversion to
farmland nothing but a loss of their rights of common for the benefit of foreigners
and intruders.
When the King took a personal interest
in forwarding the scheme alarm spread to
the towns bordering the fenlands, such as Cambridge and Huntingdon, which had
long since been strongholds of Puritanism and where the King's motives were
suspect. The opposition, fundamentally political, crystallized before long in the
person of Oliver Cromwell, whose energetic resistance brought the project to a halt.
Vermuyden was undaunted, however, and even during the years of civil war he
continued to put forward his plans. In 1649 Parliament authorized a renewal of
operations and in 1653 his perseverance was rewarded when the drainage works
of the Great Level were declared complete. But Vermuyden had ruined himself
financially and he passed into impoverished obscurity; neither the place nor the
date of his death is known. Although in subsequent years much more work had to
be done, especially in improving the outfalls of the rivers, England owes the
reclamation of a substantial acreage of her most fertile land to this single-minded
Dutchman.
Prussia
In the seventeenth century the elector
of Brandenburg and then the Prussian kings,
Frederick William I and Frederick the Great, set about the rehabilitation of the
heaths, bogs and flooded areas of Brandenburg and East Prussia. The work was
carried out by the Frisian Count Leonhard van Haarlem, who was familiar with
Dutch methods. He encountered the same difficulties as had Vermuyden: fever,
sickness, the hostility of the ferrymen and fishermen who feared to lose their
livelihood. In East Prussia a number of the new settlers forsook the land won from
the bogs, and Frederick William had to threaten with death those who left their
farms. As in England, despite setbacks, incidents and difficulties of all kinds,
Prussia won, in Frederick the Great's phrase, 'a principality without a war'.
Water technology
In the baroque period waterworks took
a more frivolous turn. Basins, fountains,
cascades and grottoes enlivened any suggestion of formality in the gardens: hosts
surprised their guests with hydraulic organs imitating various sounds, or sprays of
water which besprinkled unwary strollers. In the princely courts of that period
engineers used their knowledge and skill to create settings, deceptions and
whimwhams which today seem childish. Sea battles were re-enacted and
spectacular entertainments mounted upon floating stages; water invaded the
theatres, with storm and shipwreck becoming for a time an essential part of drama
and even of opera. The single object of such diversions was to please the senses
and the imagination; none the less they helped to perfect water techniques. By the
end of the rococo period a new age was starting, that of the natural sciences and
industrialization.
New ways to harness the power of water
were now sought. Since prehistoric times
man had known how to make modest use of the energy of flowing water. In the
workshops of the Middle Ages water had of course long been playing the part to be
taken by steam in the factories of the nineteenth century; without it many flour mills,
saw mills, powder mills, paper manufactories, foundries and grinding shops so
important in medieval economy would never have come to life, while without pumps
mining would have been almost impossible.
A water turbine was invented as early
as 1750 by Dr Johann von Segner of
Gottingen. This was a 'reaction turbine' and consisted of a cylindrical vessel with
two nozzles inserted at the sides of the base. When the cylinder was filled with
water the thrust of the water leaving the nozzles made the cylinder revolve about its
own axis. But Segner himself regarded this 'turbine' as little more than a toy, and
three quarters of a century passed before the principle was applied successfully to
a practical water-powered prime-mover.
In 1826 the Paris Societe d'Encouragement
offered a prize of six thousand francs
for the construction of an economical turbine with high performance. Many inventors
set to work, encouraged by industrialists. The prize-winner was Benoit Fourneyron,
a brilliant young French engineer, who built a radial turbine. Shortly afterwards
hundreds of patents were taken out in the United States for as many sorts of
turbine, some of steel, some of cast-iron. In the twentieth century, giant water
turbines came into use in all parts of the world, converting the energy of falling water
into electricity.
The great barrages and their associated
hydro-electric installations are the most
impressive technological achievements of our own time, and they have had a large
part in changing the appearance of the landscape. They convert streams into lakes,
seal up gorges and defiles, hold back enormous rivers, and thus permit the
watering of parched valleys and of deserts. Description of them seems to demand
superlatives. The enthusiast for technical achievement will certainly regard the high
walls of smooth concrete and their graceful lines as a pleasing combination of the
functional and the aesthetic. For a few years the 932-foot high Grand Dixence Dam
in Switzerland, completed in 1961, had the distinction of being the world's tallest,
but for the time being at least the record goes to Ingurskaya Dam I in the U.S.S.R.
with a height of 988 feet. The barrage across the fi Mahanadi River in India,
combination of concrete and earth dams, has a total length of over fifteen miles.
The Owen Falls dam across I the White Nile where it leaves Lake Victoria Nyanza
makes the I lake in effect a reservoir with an area of nearly 27,000 square miles.
The advantages of such awe-inspiring engineering feats are not always obvious,
however, to those who are displaced as the waters rise and submerge their former
homelands. The building of the Kariba Dam, for example, created a man-made
lake which will eventually cover an area of two thousand square miles. Nor was the
Zambezi lightly conquered even by the massive resources of an international
engineering consortium: more than once the river in unprecedented flood
devastated the work being carried out in the Kariba Gorge. With the building of the
High Dam at Sadd el-Aali on the Nile, a few miles above the older Aswan Dam, the
valley above it is being turned into a lake three hundred miles long. Beneath its
waters will disappear not only temples, tombs and many prehistoric sites of great
interest, but also villages, good agricultural land and the Sudanese town of Wadi
Haifa. Nevertheless, to Egypt as a whole the value of this immense reservoir and of
the hydro-electricity produced by the scheme outweighs other considerations. We
shall turn later to some other large-scale plans for altering the face of the earth. But
that scheme known by the name of Atlantropa, conceived by the German engineer
Hermann Soergel in 1928, deserves a mention here.
Soergel's plan was to build dams across
the Dardanelles and the Straits of
Gibraltar, with large locks to allow the passage of ships, so that the Mediterranean
would be steadily reduced in area because water lost by evaporation would not be
replaced (as it is at present) by inflow from the Atlantic and Black Sea. He
calculated that in a hundred years the Mediterranean would have fallen 330 feet,
and that then the building of two more dams, one across the Straits of Messina and
one from Sicily to Tunis, would divide the Mediterranean into two basins whose
water level could be controlled. All the countries bordering those sea basins would
gain an enormous acreage of fertile land, and in addition the dams would supply
hydro-electricity. Europe and Africa would be so much closer that they would
become one continent, to be called Atlantropa.
This was not the only bold scheme put
forward by Hermann Soergel. In 1935 he
proposed that the River Congo should be dammed and its waters turned
northwards to create an enormous lake in the swampy Congo Basin, at the heart of
the continent. The main outlet from this lake would be northwards into Lake Chad,
which is considered by geologists to be very much smaller than it was some ten
thousand years ago and today has no outlet to the sea. Restored to the size of an
inland sea, Lake Chad would provide irrigation for the Sahara Desert. It would have
an outlet to the eastern Mediterranean basin and thus also provide a new navigable
waterway longer than the Nile.
These projects belong, fortunately perhaps,
to the domain of Utopia. Geology,
climate, economics and politics stand in the way; man too recoils against the
realization of such titanic schemes. If the dams of Soergel's plan were to be
bombarded and destroyed during hostilities, a wave a thousand feet high would
rush from one end of the Mediterranean to the other, drowning millions of the
people living on its shores. Nor is it possible to foresee all the results of
interference with the ocean currents, for example, on this scale. But perhaps other
and more practicable projects will replace Soergel's Atlantropa.
