Stories tagged dams

Here's the White Salmon River returning to it's natural course after about 100 years (thanks to an exploding dam!):

Explosive Breach of Condit Dam from Andy Maser on Vimeo.

Preeeetttty neat. The idea is to restore the river and its surroundings to a more natural state for the wildlife. And also, I hope, for the sake of exploding something.

(io9 via National Geographic.)

An underwater turbine farm producing enough electricity to power 250,000 homes could one day be installed in the Mississippi. Though the project faces some funding and development challenges, the technology has real promise for a river delta starved of sediments. What if dams could be removed and replaced with freestanding turbines?

Mar
06
2009

Zipingpu Dam: Upriver from the town of Dujiangyan, Sichuan, China.
Zipingpu Dam: Upriver from the town of Dujiangyan, Sichuan, China.Courtesy TaylorMiles
Scientists suspect that last year’s devastating earthquake in China may not have been a natural disaster. A nearby dam may have weakened fault lines and spurred the magnitude-7.9 quake.

The Zipingpu Dam is only 3.4 miles from the epicenter of the May 12, 2008 earthquake in Sichuan province. This quake killed 80,000 people and left 5 million homeless. Although the area exhibits a lot of seismic activity, an earthquake of this magnitude is unusual.

Water in the Zipingpu Dam

The Zipingpu Dam is one of nearly 400 hydroelectric dams in the area. It rises 511 feet high and holds 315 million tons of water. US and Chinese scientists believe that the weight of the water increased the direct pressure on the fault line below. This volume of water would exert 25 times more pressure annually than is natural. Additionally, water seeping into the rock acted as a lubricant and relaxed the tension between the two sides of the fault line. Since the reservoir was filled in 2004, the water caused a chain of ruptures culminating in this massive earthquake.

Worldwide impact on green energy

Sichuan province is the epicenter for more than just a powerful earthquake. It is here that most of China’s hydroelectric power is generated, an integral component of its renewable power plans. The area also produces much of the world’s wind turbine equipment. The infrastructure will take months or years to repair.

Before the quake, China admitted to major flaws in the country’s 87,000 dams. The earthquake damaged other dams and power stations and several major reservoirs were drained to prevent their dams from failing.

Feb
15
2008

Drawing down: The white banks show the one-time high water mark of Lake Meade in Arizona. One group of researchers say there's a 50 percent chance the lake could dry up by the year 2021
Drawing down: The white banks show the one-time high water mark of Lake Meade in Arizona. One group of researchers say there's a 50 percent chance the lake could dry up by the year 2021Courtesy amysh
Have you ever been to Hoover Dam? It’s a popular day trip destination for those looking for a break from the gambling in Las Vegas.

One of the impressive sights is the huge body of water stopped up behind the dam: Lake Meade. The water stretches and snakes for miles and miles upstream on the Colorado River, which cuts its way through the Grand Canyon. That reservoir of water is also the main drinking supply for much of the southwest U.S.

But analysts from San Diego's Scripps Institution of Oceanography that there’s a 50 percent chance that water will dry up by 2021. In a shorter time span, they say that there’s a 10 percent chance water in the lake will not be usable for drinking by 2013, just five years away.

The dire predictions are based on global climate change factors along with a growing demand for water in southern Nevada and southern California.

Due to current drought conditions, Lake Meade and its sister reservoir, Lake Powell upstream from the Grand Canyon, are only currently half full. Combined, they provide water to 27 million people spread over seven states.

But an official from the Central Arizona Project said that the predictions are alarmist and absurd and that the reservoirs are in no danger of drying up.

And I remember just a couple weeks ago we posted a story here on the Buzz that Rocky Mountain areas have seen wondrous amounts of snowfall this winter. A lot of that snow runoff finds its way into the Colorado River.

Do you have any deep thoughts to share on the southwest water situation? Post them here and let other Science Buzz readers know how you feel.