But, the vast reservoir was built for far more than recreation. In fact, the massive Hoover Dam, which was completed in 1935, provides this desert region and surrounding states with a reliable water supply from the Colorado River as well as an excellent and inexpensive source of electricity.

Covering the state lines of Arizona and Nevada, Lake Mead stores water from the vast Colorado River, which runs through a whopping seven states – Arizona, California, Nevada, Utah, Wyoming, Colorado and New Mexico. So, to say that Lake Mead and the irreplaceable Colorado River are important to the citizens of the western states, would be a huge understatement.

However, for the past decade Lake Mead has been battling the worst 10-year drought in recorded history along the Colorado River, which feeds the 110-mile-long reservoir.

Since 1999, Lake Mead has dropped about 1 percent a year. It is estimated that by 2012, the lake’s surface could fall below the existing pipe that delivers 40 percent of Las Vegas’s water.

In 2000, the water level at Lake Mead was 1,214 feet, close to its all-time high, but it has been dropping ever since. When Lake Mead was built during the 1920s and 1930s, the western United States was experiencing one of the wettest periods of the past 1,200 years.

Even today, our so-called drought is still wetter than the average precipitation for the area averaged over centuries. In other words, for the past 75 years, we’ve had more moisture than we ever realized. And, we definitely took it for granted.

Farmers have been growing rice by flooding arid farmland with water from Lake Mead,  desert community residents have been maintaining lush front lawns, and avid golfers depend on green, healthy courses in areas where temperatures typically exceeds 100 degrees Fahrenheit during the summer.

A combination of a solid demand for Lake Mead’s thirst-quenching water and an ever-changing climate has resulted in a 100 foot drop in Mead’s water level since 2000. While that might not look like a great deal of water loss because it is just 10 percent under the lake’s 1983 high water mark, we have to remember that Lake Mead is like a martini glass.

The vast reservoir is wide at the top but narrow at the bottom. So that 10 percent loss of water actually represents a loss of half of Lake Mead’s water supply. This huge loss happened in just nine years – The lake went form 96 percent capacity to roughly 43 percent.

Amazingly, when full, Lake Mead can hold an astonishing 9.3 trillion gallons of water. This is an amount equal to the water that flows through the Colorado River in a two-year period.

And, this is water that is put to good use. Lake Mead’s life-sustaining water is used for many things. It irrigates a million acres of crops throughout the western United States and Mexico, and the reservoir supplies water to tens of millions of people.

The massive and mighty Hoover Dam generates enough electricity to power approximately a half-million homes. But that’s not all. The power from Hoover Dam is also used to transport water up and across the Sierra Nevada Mountains on its way to Southern California.

But, however, the lake continues to shrink. Lake Mead’s water level fell 14 feet last year, and the Bureau of Reclamation has projected the level will drop 14 more feet this summer. That will bring it perilously close to 1,075 feet, the point at which the federal government can step in and declare a drought condition, forcing a reduction of 400,000 acre-feet drawn from Lake Mead per year.

A typical Las Vegas home uses a half acre-foot of water per year, so such a reduction would be equal to turning the tap off for 800,000 households.
Going beyond the implications for residents living in areas supplied by Lake Mead, the water loss has ramifications for the local economy too. It was recently estimated that Lake Mead National Recreation Area, along with affiliated marine operators, were losing some where in the neighborhood of three million dollars for every ten foot of lake lost to this devastating drought.

Currently, Lake Mead’s water level is hanging close to 1095.26 feet above sea level. The end-of-year projection is now predicting that Lake Mead will drop several more feet below its current level. This is a huge loss considering the lake is considered full at 1,219 feet.

The year 2009 started out well as officials projected that Lake Mead could receive an additional one million acre-feet of water based on the snowpack in the Rocky Mountains. Unfortunatly, however, the thaw did not translate into the expected runoff, and Lake Mead and the Colorado River’s water shortage problem marched on.

In 2008, the Scripps Institute of Oceanography issued their “When Will Lake Mead Go Dry?” report. The report said there is a 50 percent chance that Lake Mead will dry up by the year 2021. If this happens, it could mean no more water, no more pumping and no more electricity for many, many people.

There is, however, some good news. Strong conservation efforts are helping this serious condition. For example, Southern Nevada has significantly reduced its water draw from 325,000 acre-feet a year in 2000 to 265,000 acre-feet in 2009. Even with this reduction, the grand Colorado River still remains over utilized.

This is easy to see when you consider that millions of acre-feet of H20 are rushed to California, Nevada, and Mexico each year. This continually drains and strains both Lake Mead and neighboring Lake Powell faster than either lake can be replenished.

Some of the conservation solutions and suggestions include “grass buyback” programs to convince residents of the benefits of installing drought-tolerant landscaping, tax incentives for swimming pool-covers as well as the inevitable water rate hikes.

One of the more radical ideas involves pumping water from the eastern United States, where many regions’ rivers have been inundated with extensive flooding, over the Rockies to the western, sweltering states. Another interesting proposal lies beyond the shores of California, where there is a vast, open ocean of water available for desalinization.
While these are possibly viable alternatives, the power and financial requirements for either proposal would be enormous.

Whatever the solution to the Lake Mead water crisis is, it is likely not going to be a simple one. If the drought-like conditions continue, action will likely need to be taken sooner rather than later in order to save the reservoir.

It might be discovered that the money and time it will take to quench the western United States’ thirst are like the water supply. They are all running short.

One of the most dramatic and deliberate impacts that humans have had on the natural environment involve dams. By diverting rivers to meet water, energy, and transportation needs, dams have had a tremendous impact on the way people are able to live.

According to the Swedish Research Council, the flow of water in more than half of the world’s rivers is regulated by dams. Not counting irrigation for agriculture, 172 of the 292 largest rivers are controlled. Taken together, these dams can store about 15 percent of the annual freshwater runoff in the world.

The Three Gorges dam on the Yangtze River in China, shown here still under construction, has the distinction of being the largest. It’s planned to be 200 yards tall! It’s also planned to be the largest source of hydroelectric power in the world, and will generate the equivalent electricity of 15 nuclear power plants. It will be completed in 2009.

It [displaced] more than 1 million people. The 265 billion gallons of raw sewage and 700 million tons of sediment deposited in the Yangtze River annually will no longer be carried out to sea and will back up in the reservoir. Over 1,000 mines and factories containing potentially hazardous materials will be submerged. But the largest risk is the catastrophe that could occur from an error in construction, which has been so plagued by corruption that even the state-controlled media has criticized the loose financing of the project. This project, on a colossal scale, highlights the looming environmental risks to China’s rise. Asia Times

Chinese environmental scientists are worried that the future operation of the Three Gorges dam could cause a wide strip of land stretching for thousands of kilometres to become geologically unstable, seriously polluted and a dangerous source of epidemic disease. Source

Large dam construction projects can be seen as humankind’s attempt to control nature by changing the course and speed of a river. Is controlling nature a worthwhile goal for humankind? Should we try to live in harmony with nature instead? Throughout history, philosophers such as John Muir, Henry David Thoreau, Rachel Carson, and Gifford Pinchot have argued about these and other ideas relating to human interaction with the natural world. Lesson Plans

What’s left? Rivers in the tundra of Alaska, and rivers in northern coniferous forests of Siberia. All the temperate rivers are taken. Canada is already successfully building dams in sparsely populated areas for the export of electricity and fresh water.

Thanks to Mikel and his amazing new service.

]]> http://www.sprol.com/2005/05/three-gorges-dam/feed/ 7 http://www.sprol.com/2005/04/growing-chlorine/ http://www.sprol.com/2005/04/growing-chlorine/#comments Fri, 22 Apr 2005 17:25:00 +0000 Automatt http://13
The Occidental Chemical Corporation operates the Niagara Plant in Niagara Falls, NY. Here, they are making Chlorine, seventeen million pounds of it at a time. Chlorine is incredibly useful to industry due to its wild effects on organic chemistry. Lots of it is used to bleach paper; even a medium sized pulp mill can use 90 tons a week. Lots of that winds up in a river somewhere. It all comes from here. This one factory is probably responsibly for poisioning most of the midatlantic.

When talking about a huge industrial production facility like this one, the word factory is interchangable with plant. Most plants of the vegetable kind are generally pretty benign. This kind of plant is not.

Free clorine, grown here, is rare in nature and is incredibly toxic to life — so toxic that chlorine gas was used by the German Army against the French in 1915 as a weapon of war. Producers describe it as “fatal after a few breaths.” Since most uses for this stuff are industrial, accidents with chlorine tend to happen around other chemicals, and these interactions have effects that are combinatorialy more harmful to life.

Chloride, the ion Cl- on the other hand is common in nature, and is found everywhere, especially in seawater. In inland seas like the Great Salt Lake and the Dead Sea, places where ocean water has evaporated, it is also abundant. The cloride in these salty waters was emitted volcanically over millions of years, concentrated by the motion of water. It didn’t go away. It persisted. Manufactured chlorine also persists in the environment. It is permanent.

Most industrially produced chlorine is made through the electrolysis of brine, reusing these salts; This factory is probably placed right where it is because of the readily available water and electricity in Niagra Falls, NY. According to the EPA, over a million people would be harmed in a worst-case accident at this plant, which is why most people don’t want to live near a chlorine factory.

As toxic as chlorine is, lots of chlorine factories would be worse to live near than this one. For some incalculably stupid reason, people still make chlorine using mercury, a process invented in the 19th century. Mercury, which is then either released into the air (see pdf), or ‘lost’, also persists in the environment. When people eat fish that eat fish, the environmental mercury is concentrated and causes all sorts of serious health problems.

For some reason, the Google Maps satellite view is blurred out even though other areas around there are a much higher resolution. For this reason the image above comes from Microsoft’s TerraServer. On both you can see how the factory is positioned relative to the surrounding environment, and the effect it has on the land. As usual, click the picture to visit.

]]> http://www.sprol.com/2005/04/growing-chlorine/feed/ 4