Yule Heibel on 2008-04-28
- one of the biggest discrepancies btw resource and consumption is for Asia -- how come? Also, N.America: that might be skewed, given Canada's vast water supply, yet relative sparse population density.
- interesting article, w/ some useful visuals that show just how disproportionately much water we use for agriculture. I'd like to use this article together with some relevant ones on Victoria's sewage treatment issues to connect some dots re. infrastructure capacity; capturing engery from waste (sewage); using biowaste not corn or soybeans for ethanol/ biofuels; capturing water for agriculture from sewage; and producing agriculture locally especially in the face of rising food prices.
This is not to say the world is running out of water. The same amount exists on Earth today as millions of years ago — roughly 360 quintillion gallons. It evaporates, coalesces in clouds, falls as rain, seeps into the earth, and emerges in springs to feed rivers and lakes, an endless hydrologic cycle ordained by immutable laws of chemistry. But 97 percent of it is in the oceans, where it's useless unless the salt can be removed — a process that consumes enormous quantities of energy. Water fit for drinking, irrigation, husbandry, and other human uses can't always be found where people need it, and it's heavy and expensive to transport. Like oil, water is not equitably distributed or respectful of political boundaries; about 50 percent of the world's freshwater lies in a half-dozen lucky countries.
Freshwater is the ultimate renewable resource, but humanity is extracting and polluting it faster than it can be replenished. Rampant economic growth — more homes, more businesses, more water-intensive products and processes, a rising standard of living — has simply outstripped the ready supply, especially in historically dry regions. Compounding the problem, the hydrologic cycle is growing less predictable as climate change alters established temperature patterns around the globe.

London's infrastructure has a more fundamental problem: It's creaking with age. "Charles Dickens was the best-selling author when most of our pipe work went in," says John Halsall, director of water services at Thames Water, the private company that provides water to greater London. Thames Water maintains more than 300 reservoirs, 99 treatment plants, and more than 20,000 miles of pipe. The city's water system was a triumph of 19th-century engineering, but one-third of the mains are more than 150 years old, veterans of such scourges as Hitler's bombs and corrosively acidic soil. Thames' system leaks 180 million gallons a day, 30 percent of overall flow. To fix a leak, which the company does some 82,000 times a year, it has to shut down traffic and dig up the streets in one of the most congested cities on Earth. A brief walk around the West End turns up a half-dozen work crews digging up Victorian mains, scooping through layers of history to repair the pipes one segment at a time.
Replacing all the Victorian pipes would cost an estimated $3.6 billion. The conundrum facing Thames Water is how to upgrade the crumbling system without tearing up the city or bankrupting the company. There are two sets of solutions: On one hand are small, local, high tech projects. On the other are traditional large-scale civil engineering initiatives that have been a staple of water management since the Roman Empire. Tompkins favors the small-scale approach. In particular, he likes metering. There's no way to measure the water flowing through much of the underground infrastructure, which makes it hard to identify leaky sections. Likewise, not even a quarter of the city's households are metered, and that makes it difficult to encourage conservation. If consumers understood exactly how much they were using, Tompkins reasons, perhaps they would change their behavior, like a dieter motivated by the scale readout every morning.

Thames Water's most controversial project is a $400 million desalination plant called the Thames Gateway. The proposed facility could take in seawater, filter out the salt, and deliver 35 million gallons of drinking water a day during drought emergencies. Desalination would essentially drought-proof the city, the company claims. It's an appealing solution. The ocean is practically limitless, and the plant would run on biodiesel, giving it a green imprimatur. The project was moving through the approval process in 2006 when London's tough, left-leaning mayor, Ken Livingstone, blocked it.
Livingstone argued that the plant was too expensive and that desalination is too energy-intensive. Stripping seawater of its salt is a pricey way to obtain freshwater, cost-effective only for high-end uses like drinking, but not bathing or watering gardens. And the mayor questioned the proposal's environmental cred: Biodiesel emits carbon, and desalination's super-salty byproduct is toxic to marine life. Thames Water would do better, he insisted, to repair London's decrepit labyrinth of pipes.


This link has been bookmarked by 5 people . It was first bookmarked on 26 Apr 2008, by Madison Guy.
- interesting article, w/ some useful visuals that show just how disproportionately much water we use for agriculture. I'd like to use this article together with some relevant ones on Victoria's sewage treatment issues to connect some dots re. infrastructure capacity; capturing engery from waste (sewage); using biowaste not corn or soybeans for ethanol/ biofuels; capturing water for agriculture from sewage; and producing agriculture locally especially in the face of rising food prices.
This is not to say the world is running out of water. The same amount exists on Earth today as millions of years ago — roughly 360 quintillion gallons. It evaporates, coalesces in clouds, falls as rain, seeps into the earth, and emerges in springs to feed rivers and lakes, an endless hydrologic cycle ordained by immutable laws of chemistry. But 97 percent of it is in the oceans, where it's useless unless the salt can be removed — a process that consumes enormous quantities of energy. Water fit for drinking, irrigation, husbandry, and other human uses can't always be found where people need it, and it's heavy and expensive to transport. Like oil, water is not equitably distributed or respectful of political boundaries; about 50 percent of the world's freshwater lies in a half-dozen lucky countries.
Freshwater is the ultimate renewable resource, but humanity is extracting and polluting it faster than it can be replenished. Rampant economic growth — more homes, more businesses, more water-intensive products and processes, a rising standard of living — has simply outstripped the ready supply, especially in historically dry regions. Compounding the problem, the hydrologic cycle is growing less predictable as climate change alters established temperature patterns around the globe.
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