Taxonomy term

dam

Geologic Column: Dams in distress

The United States has more than 90,000 dams, with an average age of 50 years. Recent failures highlight the potential for catastrophe and the need for infrastructure maintenance. 

12 Dec 2017

Geomedia: Books: 'Floodpath' recounts the deadly collapse of California's St. Francis Dam

The catastrophic collapse of the St. Francis Dam, located 80 kilometers north of downtown Los Angeles and east of the town of Santa Clarita, just before midnight on March 12, 1928, claimed more than 400 lives when towering floodwaters destroyed homes, bridges and farmland, as they swept through downstream communities. The disaster was initially blamed on the failure of the west abutment, anchored in soft conglomerate rock. Additional studies have revised this explanation, with recent research citing other geologic and design factors that likely contributed. Regardless, the collapse effectively ended the career of William Mulholland, the self-taught engineer whose 1913 Owens Valley Aqueduct made the explosive growth of Los Angeles possible. Yet, despite the magnitude of the disaster and its impact on local and national policy, it has been almost entirely forgotten, except by a few historians.

08 Jun 2016

Widespread malaria risk from African dams

Large dams cause more than 1 million cases of malaria annually in sub-Saharan Africa, according to the authors of a new study published in Malaria Journal.
 
17 Jan 2016

Damming the salmon

In the 1940s, the state of Idaho decided that the Salmon River would be left to flow freely while the Snake would be developed for hydroelectric power to become Idaho’s workhorse river. To date, a total of 15 dams have been built along the Snake for a variety of purposes, from irrigation to flood control to hydroelectricity. Hells Canyon is home to three hydroelectric impoundments: the Brownlee, Oxbow and Hells Canyon dams, built in 1959, 1961 and 1967, respectively. Together they have a maximum capacity of 391 megawatts of power production. 
 
18 Sep 2015

Iraq's biggest dam on unsure footing

Much of Iraq’s national power grid, as well as its irrigation and municipal water supplies, depend on Mosul Dam, a large earthen structure on the Tigris River about 70 kilometers upstream from Mosul, Iraq’s third-largest city. However, the dam, constructed in the 1980s, was built upon a geologically weak foundation, raising worries about its safety.
04 Jun 2015

Ground-shaking research: How humans trigger earthquakes

An uptick in the occurrence of earthquakes in places where they used to be rare — like Oklahoma, where waste-fluid injection is triggering frequent quakes — prompts a look at the many ways humans can and do induce seismicity.

05 Apr 2015

Can dam releases restore river ecosystems?

Scientists and dam managers are studying how the very dams that disrupt river ecosystems can be used to restore them using controlled releases of water.

18 Mar 2015

Benchmarks: May 31, 1889: Johnstown flood kills thousands

“It seemed to me as if all the destructive elements of the Creator had been turned loose at once in that awful current of water.” That’s how Col. Elias Unger, president of the corporation that maintained a dam and resort property called the South Fork Fishing and Hunting Club, described the water unleashed on the afternoon of May 31, 1889, when a dam at the club broke 23 kilometers above Johnstown, Pa. A little more than an hour later, a wall of water reached the town. In all, more than 2,200 people died in what is known as the Johnstown Flood.

02 May 2011

Benchmarks: November 27, 1873: Red River logjam removed for good

Throughout the 1800s, America’s eastern and southeastern coastal rivers acted as highways for shipping. Generally winding with shallow slopes, the rivers could be plied easily by barges and steamboats, but one particular water body — the main channel of the Red River that runs from Arkansas through Louisiana — thwarted the plans of shippers for much of the 19th century. A massive entanglement of logs, stumps and branches, known as the Great Raft, blocked the Red from Fulton, Ark, to about Shreveport, La. But on Nov. 27, 1873, after more than 40 years of trying, the raft was destroyed and boats could travel unimpeded down the main channel of the Red River.
 
05 Nov 2010

Down to Earth With: Matt Kondolf

As a fluvial geomorphologist teaching in the Landscape Architecture and Environmental Planning Department at the University of California at Berkeley, Matt Kondolf is an ambassador from the earth sciences to landscape designers and environmental planners. Kondolf’s research in river management ranges from the impacts of urbanization on runoff and sediment yield, to river restoration, to managing salmon populations and fishing. In classes like “Hydrology for Planners” and “Ecological Analysis in Urban Design,” he encourages up-and-coming environmental planners and designers to think carefully about the geologic processes that control river formation, as well as the roles that rivers play within ecosystems. He is also active in the policy discussions that are shaping California’s and the nation’s approaches to river management.

02 Jan 2010