Water is a simple concept to many people, but it's one of our most essential resources. Unsanitary water leads to rapidly spreading disease and a higher risk of famine as food sources are compromised. Complete lack of water spells death much more quickly. It's also an important power source – it's fairly heavy and easy to pour and manipulate.
Humans throughout history have always tried to increase the availability of water, either by settling near streams and rivers or by developing technologies and methods to bring the water to them. Let's take a look at a few interesting devices and innovative techniques people have used to get this precious resource, make it safe to drink, or use it to save some labor.
Around 1500 B.C., the ancient Egyptians discovered that adding a certain compound to dirty water would attract the dirty part, leaving much cleaner water behind. This compound was alum, or aluminum sulfate, and it's still occasionally used today by hikers and campers to purify water they find.
When added to water, alum reacts with bicorbonate alkalinities in the water, forming a gel that traps the sediment and most of the fine particles in the water. This gel falls to the bottom, and the water above is nearly clean.
Humans have been grinding grain for a long time, but it got a whole lot easier with the invention of the water mill. The first evidence of one is the Hydraulic Wheel of Perachora, developed by the ancient Greeks around 300 B.C. It used a horizontal wheel, with two millstones that ground the grain as it fell from a chute above.
Water mills allowed people to produce staple foods much more efficiently, including flour, rice, corn, and rye, letting populations grow more quickly and become more robust. They were also used in the production of many other goods, like textiles, paper, lumber, and metal products.
Ancient Rome was famous for its aqueducts, but did you know they also pioneered the use of mining with water? They were usually looking for gold, particularly in the Las Médulas area, now in northwest Spain. Two basic techniques were used, sluicing and hushing, and they started around 100 B.C.
Sluicing involved diverting a stream of water over an area, which would break apart the ground and carry the material away. That water was filtered through a sluice filled with prickly shrubs, where the gold could be more easily extracted.
Hushing, used in other situations, involved storing water above an area to be mined, in tanks or by natural embankments. The water was released all at once, and the force of it would wash away sediment and material, leaving behind veins of gold (but you probably can't blame the ancient Romans for hydrofracking).
Ancient Maya (Guatemala)
What do you do when it doesn't rain for four months out of the year? If you're the ancient Maya, you come up with an incredible system for storing and distributing water, and you maintain this for 1,500 years.
Imagine a paved city, covered in plaster. When it rains, water flows through the channels and into giant reservoirs, which could hold thousands of gallons of rainwater each, ready to be used in the dry season. There were even sandboxes that filtered the water as it passed through. This was ancient Tikal, which was constructed around 500 B.C.
This system lasted until around A.D. 900, when overpopulation and overwhelming drought contributed to the collapse of the city. But until then it was one of the grandest and most impressive water projects on the planet, rivaling even the Roman aqueducts.
Civilizations around the world have undertaken countless projects, big and small, to find better ways to get clean water or use it for our purposes. Sometimes they have a massive effect on people's lives, bringing more food, wealth, and prosperity to those lucky enough to be there. What will we add to this list in the modern era?
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