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A Historical Perspective

In humid regions, primitive humans paid little attention to water. It was always present and, like air, was taken as a matter of course. However, in semiarid and arid regions, the occurrence of water controlled the activities of humans. Villages were originally built on perennial streams or around water holes. Our early movements consisted chiefly of migrations to perennial water in the dry season and ventures into new pastures or hunting grounds in the wet season.

Primitive humans learned to dig for water, possibly by observing the actions of wild horses and wolves in search of water. As soon as we learned to domesticate and rear cattle and sheep, the water well became the most important possession.

The Bible described many incidents illustrating the importance of groundwater supplies to the tribes of Israel. Abraham and Isaac were renowned for their success at constructing wells. The Father of Modern Hydrology, O.E. Meinzer once said that the twenty-sixth chapter of Genesis read like a water-supply paper. Most people recall from the Old Testament how the Jews suffered for want of water in their 40 years of wandering in the deserts. To quell a near revolt by his people, Moses smote a rock with his rod and a fountain of water burst forth.

The ancient Greeks in the early seventh century BC told the story of Tantalus, Zeus' favorite mortal son who stole the ambrosia and nectar from the gods that gave the gods endless lives. Tantalus tried to share the heavenly food with mortals to give humans immortality. Zeus punished Tantalus by hurling him to Tartarus, a prison of darkness where Tantalus currently stands, trapped in the pool of water that is chin-height. He cannot drink it, though, for anytime he lowers his mouth to take a drink, the water recedes. The ancient Greeks knew the value of water, for Tantalus was sentenced to an eternal life of thirst, the most terrible punishment available. Hence, the word, tantalize.

The Romans depended on many shallow wells and springs before they built their first aqueduct in 312 BC. The soil was so rich in springs and underground streams that wells could be sunk successfully at any point, and the average depth necessary was only about 5 m. Such wells were common from the earliest period, of the Roman Empire Excavations in the Roman forum have uncovered more than 30 wells dating back to the Republic.

The drilling rather than digging of artesian wells in France and Italy began in the twelfth century and created considerable popular and scientific interest on the occurrence of underground water. The art of drilling and casing wells was actually invented, perfected, and extensively practiced by the ancient Chinese. They used bamboo poles and patience to penetrate hundreds of feet. Wells were started by the grandfather and completed by the grandson.

The most extraordinary works of ancient humans for collecting groundwater are the qanats and karezes of the Persians and Afghanies. The qanats and karezes are tunnels that connect the bottoms of shafts, which were dug by humans working as moles over long periods of time and are conspicuous over all the high central valleys of Iran. Thirty six of these tunnels supplied Teheran and the highly cultivated tributary agricultural area.

In ancient times, springs were considered the miraculous gifts of the gods; they wrought miracles and consequently were places where temples were built. These superstitions continue today with those who optimistically overestimate the therapeutic value of medicinal springs.

Prior to the latter part of the seventeenth century, it was generally assumed that the water discharged by the springs could not be derived from the rain, first because the rainfall was believed to be inadequate in quantity and second, because the Earth was believed to be too impervious to permit penetration of the rain water far below the surface. With these two erroneous postulates lightly assumed, the philosophers devoted their thought to devising ingenuous hypotheses to account in some other way for the spring and stream water.

Two main hypotheses were developed: one to the effect that sea water is conducted through subterranean channels below the mountains and is then purified and raised to the springs and the other to the effect that in the cold dark cavern under the mountains, the subterranean atmosphere and perhaps the Earth itself are condensed into the moisture. The sea water hypothesis gave rise to subsidiary ideas to explain how the sea water is freed from its salt and how it is elevated to the altitude of the springs. The removal of the salt was ascribed to processes of either naturally occurring distillation or filtration.

Beginning with the middle of the sixteenth until the close of the seventeenth century, numerous publications appeared that contained discussions of groundwater, but the two ancient or classic Greek hypotheses chiefly occupied the field, although an infiltration theory was explained in 1580 by Bernard Palissy. In the later part of the seventeenth century, Perrault, Mariotte, and Halley abandoned the theories of the past and actively undertook experimental work to determine the source and movements of groundwater, and thus was born the science of groundwater. Perrault made rainfall measurements during three years and roughly estimated the area of the drainage basin of the Seine River above a point in Burgundy and of the runoff from this same basin. He computed that the quantity of water that fell on the basin as rain or snow was about six times the quantity discharged by the river. Crude as his work was, he definitely demonstrated the fallacy of the old assumption of the inadequacy of the rainfall to account for the discharge of springs and streams.

Mariotte computed the discharge of the Seine at Paris by measuring its width, depth, and velocity at approximately its mean stage and by doing so verified Perrault's results. About the same time, Halley made crude tests of evaporation and demonstrated that the evaporation from the sea is sufficient to account for all the water supplied to the springs and streams, thus removing the need for any other mysterious subterranean channel to conduct the water from the ocean to the springs.

Centuries were required to free scientists from superstition and wild theories handed down from earlier generations regarding the unseen subsurface water. To a certain extent, we still live at a time when great misunderstanding if not superstition exist with regard to the occurrence and movement of groundwater. The elementary principle that gravity controls motions of water underground as well as at the surface is still not appreciated by all engaged in the development of the world's vast groundwater supplies.

Many people still believe that the magical forked witch stick is able to point to underground water streams and will actually twist in the hands of the operator in its endeavor to do so.

These popular superstitions are examples of the ability to believe without the foundation of facts, and this peculiar ability exists in the minds of both educated and uneducated men and women. Inasmuch as the movements of underground water cannot be observed at the surface, they have been subject to wild speculation. Even an American judge in a court case once ruled that "percolating water moves in a mysterious manner in courses unknown and unknowable."

Little by little in the last decades of the twentieth century, groundwater hydrologists dragged the water supply fraternity and the public at large kicking and screaming into a twenty-first century. Now groundwater resources are appropriately valued as often the best hope for enabling society and commerce to move forward unhindered by water shortages. Forty-seven percent of the U.S. population now depends on groundwater for its drinking water. In the Asia-Pacific region, 32% of the population is groundwater dependent; in Europe, 75%; in Latin America, 29% and in Australia, 15%.

The authors of this book played their role of ardent enthusiastic scientists during this period battling ever-present opposition to belief that significant quantities of groundwater supply could be sustained. Although we approached success in our efforts, it was still a small victory as our intent has been to reveal to the world the vast quantities of groundwater yet hidden deep within the Earth, often beneath arid lands. Thus far, there has been little confidence in our conceptual model or paradigm.

We have long believed that a planet whose surface is covered by water should not be facing water shortages. Admittedly, 97% of the Earth's water is too salty for humans and agriculture, and glaciers and ice caps put another significant portion out of reach. But we have long believed that a significant portion thought to be out of reach under the ground is not.

Energy-intensive desalting of seawater is currently too expensive except in wealthy but dry areas near seacoasts. Our fresh surface water has been allocated in most of the developed world, with Canada being a rare exception.

Although humans have learned well over the past century to conserve water in such that water use per person has actually declined, the addition of the final two billion people on the planet in the next 40 years before its population stabilizes (in accordance with most sound demographic projections) will require considerable additional water supplies. If we fail to develop additional water supplies, international strife will remain. Half of our continental land lies within river basins shared by more than one country. Multinational water claims have not and likely will not provoke war, but...