Drilling down into water issues
by Andy Bryenton
There are a few core inventions that have helped turn us, as a society, from nomadic hunters into civilised farmers and builders. The wheel isn’t even one of them; amazingly the Inca people got on well without it! Along with fire, pottery, language and grain storage, the well is one of those things which has taken us from caves to skyscrapers.
The earliest cities, in places like Sumeria and Egypt, were built around wells. A well 5,000 years old is at the very centre of Cairo, for example.
Water was scarce in these dry lands, and a well was an asset worth defending, as it was also a de facto trading post, army mustering point and hub for irrigation and animal breeding. Water makes farms, farms make wealth, and wealth, eventually, makes empires.
However, today’s wells are very different from the hand-hewn stone-lined ones of antiquity.
These days it’s not a dowser with a forked stick who seeks out underground water. Hydrologists can tell a lot from the shape of the land, as well as from the kind of rock that underlies it. These professionals can also use ground-penetrating waves to find water, acting like the sonar ‘ping’ a submarine uses to detect enemy vessels during wartime. Gravel, limestone, porous cracked-up rocks or underground sandstone can trap large quantities of useful water.
Once a likely spot is found, the trick is to drill down deep enough to establish a productive well that will last the distance through all seasons.
More than just a hole in the ground, a modern well is usually a bore sheathed with long-lasting materials to prevent cave-ins and erosion.
Deep in the underground water table, the bottom of the well is made of sturdy mesh or perforated pipe to allow water in but keep it flowing and stop it from clogging up. Now a suitable pump is needed to lift water to the surface. Modern wells usually utilise electrical means of pumping, which vary in kilowatt power according to the depth of the bore and the volume required. When it’s dry above ground, water reserves replenished by rains months or even years past await beneath the surface. Finding such reserves, and engineering the means to tap into them, is no longer a job or superstition and guesswork, but one conducted with satellite maps, specialist drilling trucks and advanced technology.