Ancient Water Supply, Conveyance and Treatment
by Lady Tammarrion de Sidana
April 2002
Water is necessary to the survival of man. From drinking, cooking, hygiene, watering animals, growing crops, transportation, power generation to excreta disposal, water has always been a very important part of humans lives. Records show that the quest for pure water began in prehistoric times. Early food-gatherers would camp in the vicinity of rivers or natural springs. Eventually towns and cities grew around these natural areas.
“Throughout recorded history large cities have been concerned with their water supplies. Even ancient cities found that local sources of supply – shallow wells, springs and brooks – were inadequate to meet the very modest sanitary demands of the day, and the inhabitants were constrained to build aqueducts which could bring water from distant sources. Such supply systems could not compare with modern types, for only a few of the wealthier people had private taps in their homes or gardens, and most citizens carried water in vessels to their homes from fountains or public outlets. Medieval cities were smaller that the ancient cities, and public water supplies were practically nonexistent. The existing aqueducts of ancient Athens, Rome and the Roman provincial cities fell into disuse, and their purposes even forgotten.” (Steel 2)
“A complex waterworks system includes a source, which may be a natural or artificial lake or impounding reservoir, a river or groundwater. An intake will be needed. Wells and springs may be considered as intakes, but special intake structures are required for lakes, reservoirs and rivers. If the source is a long distance from the city, an aqueduct, pipe line, or open channel will be needed to convey the water. If the water is from surface sources, a treatment plant will usually be required. In some cases groundwater is also treated. A pumping station will be needed in most cases to generate sufficient head [pressure] to force the water through the network of street mains. A few cities are able to depend entirely upon gravity for distribution and need no pumps; others have pumps at the source and again pump the water after treatment. The pump may discharge all or part of the water into elevated storage tanks or reservoirs. These furnish water for emergencies and also equalize demand when pumping. Finally there is the water distribution system, which includes the mains, valves, service pipes, and fire hydrants to be found in the city streets.” (Steel 84)
WATER THEORY
“Ancient philosophers focused their attention on the nature of processes involved in the production of surface flows and other phenomena related to the origin and occurrence of water in various stages of the perpetual cycle of water being conveyed from the sea to the atmosphere to the land and back again to the sea. Unfortunately, early speculation was often faulty. For example, Homer believed in the existence of large subterranean reservoirs that supplied rivers, seas, springs, and deep wells. It is interesting to note, however, that Homer understood the dependence of flow n the Greek aqueducts on both conveyance cross-section and velocity. This knowledge was lost to the Romans and the proper relationship between area, velocity, (p.2) and rate of flow remained unknown until Leonardo da Vinci discovered it during the Italian Renaissance. During the first century B.C. Marcus Vitruvius, in Volume 8 of his treatise De Architectura Libri Decem (the engineer’s chief handbook during the Middle Ages) set forth a theory generally considered to be the predecessor of modern notions of the hydrologic cycle. He hypothesized that rain and snow falling in mountainous areas infiltrated the earth’s surface and later appeared in the lowlands as streams and springs.
In spite of the inaccurate theories proposed in ancient times, it is only fair to state that practical application of various hydrologic principles was often carried out with considerable success. For example, about 4000 B.C. a dam was constructed across the Nile to permit reclamation of previously barren lands for agricultural production. Several thousand years later a canal to convey fresh water from Cairo to Suez was built. Mesopotamian towns were protected against floods by high earthen walls. the Greek and Roman aqueducts and early Chinese irrigation and flood control works are also significant projects.
Near the end of the fifteenth century the trend toward a more scientific approach to hydrology based on the observation of hydrologic phenomena became evident. Leondardo da Vinci and Bernard Palissy independently reached an accurate understanding of the water cycle. They apparently based their theories more on observation than on purely philosophical reasoning. Nevertheless, until the seventeenth century it seems evident that little if any effort was directed toward obtaining quantitative measurements of hydrologic variables.
The advent of what might be called the “modern” science of hydrology is usually considered to begin with the studies of such pioneers as Perrault, Mariotte, and Halley in the seventeenth century. Perrault obtained measurements of rainfall in the Seine River drainage basin over a period of three years. Using these and measurements of runoff, and knowing the drainage size area, he showed that rainfall was adequate in quantity to account for river flows. He also made measurements of evaporation and capillarity. Mariotte gauged the velocity of flow of the River Seine. Recorded velocities were translated into terms of discharge by introducing measurements of the river cross section. The English astronomer Halley measured the rate of evaporation of the Mediterranean Sea and concluded that the amount of water evaporated was sufficient to account for the outflow of rivers tributary to the sea. Measurements such as these, although crude, permitted reliable conclusions to be drawn regarding the hydrologic phenomena being studied.”
It was not until the 18th century that numerous advances in hydrologic theory and insturmentation occurred. The Bernoulli piezometer, the Pitot tube, bernoulli’s theorem, and the Che’zy formula are some examples.” (Viessman 1)
Water Conveyance
“The waterworks engineer of ancient times labored under the severe handicap of having no type of pipe that could withstand even moderate pressures. He used pipe of clay, lead, and bored wood in small sizes, but even with these, as with masonry aqueducts and tunnels, he followed the hydraulic grade line and rarely placed conduits under pressure.
In the seventeenth century the first experiments were made with cast-iron pipe but it was not until the middle of the eighteenth century that these pipes were cheap enough for wide use. The durability of cast iron and its freedom from breaks and leakages soon made its use almost universal, although steel and other materials were also used. This advance, together with improved pumping methods, made it economically possible for all but the smallest villages to obtain water supplies and to deliver the water into the homes of the citizens.” (Steel 2)
“Cast iron is the material most used for city water pipes. it is resistant to corrosion and accordingly is long-lived. Cast-iron pipe at Versailles, France, was dug up after being in use for 250 years and found in good condition. More of this pipe, in use since 1664, is still in service.” (Steel 88)
Water Treatment
“Recorded knowledge of water treatment is found in Sanskrit medical lore and in Egyptian inscriptions. Pictures of apparatus to clarify liquids (both water and wine) have been found on Egyptian walls dating back to the fifteenth century B.C. Boiling of water, the use of wick siphons, filtration through porous vessels, and even filtration with sand and gravel, as means to purify water are methods that have been prescribed for thousands of years. In his writings on public hygiene, Hippocrates (460 - 354 B.C.) directed attention principally to the importance of water in the maintenance of health, but he also prescribed that rainwater should be boiled and strained. The cloth bag that he recommended for straining became known in later times as "Hippocrates' sleeve". “ (Moeller 126) The Romans demonstrated a similar awareness of the merits of pure water; witness the extensive aqueduct systems they developed, as well as their use of settling reservoirs to purify water, their rulings that unwholesome water should only be used for irrigation, and the passage of laws prohibiting the malicious polluting of water (Frontius no #)
Public water supplies, already developed in ancient times, assumed added importance with the progressive increase in urbanization. But though they were clearly beneficial in distributing water of uniform quality, large numbers of people ran the risk of having adverse effects when the water was unsafe to drink. Evidence that drinking water problems are not just a problem today may be found in passages from the Bible the plagues.
The Bible, Exodus 7:21: “... and all the water that was in the Nile turned to blood. And the fish in the Nile died, and the Nile became foul, so that the Egyptians could not drink water from the Nile. And all the Egyptians dug round about the Nile for water to drink, for they could not drink the water of the Nile.”
“While many of the ancient cultures had high standards of sanitation, these were somehow lost during the Middle Ages. During that time the outbreak of (waterborne) diseases were mostly thought to be acts of God, in response to sin, and the only treatment was thought to be penitence.” (Moeller 126)
“Although some cities were able to collect safe water from uninhabited regions and thereby reduce waterborne disease to a low level, many others found that their supplies were dangerously polluted and that the danger was increasing as population increased upon watersheds. Accordingly treatment methods were developed that, when properly applied, reduced the hazard.
Coagulants have been used in water treatment since at least 2000 B.C., as has filtration, however their use in municipal in the United States was not common until about 1900. The application of various treatment techniques in the early part of the twentieth century resulted in marked decrease in waterborne disease illustrated in Fig. 1-1.” (Steel 2)
Works Cited
Abrahams, Harold J., “The Water Supply of Rome.” Journal American Water Works Association December 1975: 663-668
Frontinus, Sextus Julius, The Water Supply of the City of Rome (Clemens Hershel Translator, 1973) Boston: New England Water Works Association, A.D. 97
Moeller, Dade W., Environmental Health (Revised Edition), London: Harvard University Press, 1997
Steel, E. W. & Terrence McGhee, Water Supply and Sewerage (5th Edition), New York: McGraw-Hill Book Company, 1979
Viessman Jr., Warren, John W. Knapp, Gary L. Lewis and Terrence E. Harbaugh, Introduction to Hydrology (Second Edition), New York: Harper & Row, 1977
White, K. D., Greek and Roman Technology, Ithaca: Cornell University Press, 1984
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