Dams / Reservoirs

  • LeveesCalifornia levees face risk of catastrophic failure as a result of historic drought

    Earthen levees protect dry land from floods and function as water storage and management systems. Over 21,000 kilometers of earthen levees deliver approximately two-thirds of potable water to more than twenty-three million Californians and protect more than $47 billion worth of homes and businesses from flooding. Scientists say that the ongoing extreme drought in the state poses a risk of catastrophic failure to California’s levee systems and highlights an urgent need to invest in research regarding the vulnerabilities of these systems under extreme climatic events.

  • DamsResilient rivers respond quickly to dam removal

    More than 1,000 dams have been removed across the United States because of safety concerns, sediment buildup, inefficiency, or having otherwise outlived usefulness. A paper published the other day finds that rivers are resilient and respond relatively quickly after a dam is removed. Studies show that most river channels stabilize within months or years, not decades, particularly when dams are removed rapidly.

  • African securityInternational experts analyze impacts of Ethiopian dam

    By David L. Chandler

    A new report addresses potential effects of huge construction project. According to present plans, the Grand Ethiopian Renaissance Dam (GERD) — now under construction across the Blue Nile River in Ethiopia — will be the largest hydroelectric dam in Africa, and one of the twelve largest in the world. But controversy has surrounded the project ever since it was announced in 2011 — especially concerning its possible effects on Sudan and Egypt, downstream nations that rely heavily on the waters of the Nile for agriculture, industry, and drinking water.

  • WaterAs the drought worsens, California’s conservation measures fall short

    As the drought worsens, California is doing a poor job of conserving water. Water use has declined by only 2.8 percent in February compared with the same time in 2013. Some Southern Californians are actually increasing their water use. “These are sobering statistics — disheartening statistics, considering how hard we have been working on this,” said Felicia Marcus, chairwoman of California’s water control board, which reported the findings. “We are very concern about these numbers. They highlight the need for further action.”

  • China syndromeNOAA employee charged with giving information on vulnerabilities of U.S. dams to China

    A National Weather Service (NOAA) employee is being charged by the Federal Bureau of Investigations (FBI) with stealing sensitive infrastructure data from a U.S. Army Corps of Engineers database and handing it off to a Chinese government official in Beijing.The dam database is considered sensitive data and has also been compromised by Chinese hackers in 2013, as part of a covert Chinese government operation.The database information includes details on the location, type, storage, capacity, year of construction, and other crucial details helpful in the event of any coordinated strike.

  • China syndromeChina steals confidential data on the vulnerabilities of major U.S. dams

    The U.S. Army Corps of Engineers’ National Inventory of Dams(NID) contains critical information on the vulnerabilities of the roughly 8,100 major dams in the United States. Between January and April 2013, U.S. intelligence agencies spotted several attempts by China’s People’s Liberation Army (PLA) cyber-espionage unit to access the NID database and steal its contents. On Monday, National Weather Service (NWS) hydrologist Xiafen “Sherry” Chen, 59 was arrested for allegedly breaching the NID security and stealing confidential data on U.S. dam vulnerabilities. The Justice Department has raised the alarm over multiple attempts by China to steal data on U.S. critical infrastructure through individuals with privileged access to confidential databases.

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  • DamsDesign standards for dams are effective for earthquakes: study

    There has long been a concern among civil engineers that dams could fail days or weeks after an earthquake, even if no immediate evidence of a problem surfaced. Their concern has focused on possible cracks at the interface between the concrete section of a dam and the soil embankments at the dam’s sides, and on how the soil filters nestled amidst the embankments would fare. Soil filters consist of coarser grain soils than the soil used in the dam’s impervious core, and their purpose in the event of a crack in the soil, is to prevent the finer core soil particles from rapidly eroding and flushing through the filter. Since soil filters were instituted, their design standards have been based on experimental studies without detailed and validated computer modeling of the soil grains — until now.

  • Infrastructure protectionAssessing the damage of runaway barges at the Illinois River lock and dam

    It takes a synchronized lock and dam system — operating like a motorized flight of stairs on the Illinois River, using gravity to move the water — to maintain a minimum depth for boat traffic. A disastrous domino effect occurred on 19 April 2013, when heavy rain and runoff, strong winds, and river currents resulted in seven unmoored barges crashing into the dam at Marseilles, Illinois. Researchers say that the system of locks and dams on the Illinois River is vulnerable to changing climate and weather extremes. These more frequent and unpredictable conditions can cause shipping accidents, damage to lock and dam systems, streambank erosion, shipping accidents, and local flooding.

  • InfrastructureWater reservoirs for hydroelectric dams are sources of greenhouse gas emissions

    The large reservoirs of water behind the world’s 50,000 large dams are a known source of methane. Like carbon dioxide, methane is one of the greenhouse gases which trap heat near Earth’s surface and contribute to global warming.  Methane, however, has a warming effect twenty-five times more powerful than carbon dioxide. The methane comes from organic matter in the sediments that accumulate behind dams.

  • WaterDams play an important role in water pollution control

    Small dams, reservoirs and ponds trap water pollution, which provides an important benefit to water resources. This is especially relevant in agricultural lands of the Midwest U.S., where there are lots of small, but aging, dams.

  • Louisiana floodsChanges to levee system would reduce storm surge risks to New Orleans: study

    Historically, the design of Southeast Louisiana’s hurricane flood risk reduction system has hinged on raising and adding levees in response to river or hurricane events that impact the region. A new study shows that the lowering of man-made levees along 55-kilometer section of the west bank of the Lower Plaquemines river to their natural state, to allow storm surge to partially pass across the Mississippi River, will decrease storm surge upriver toward New Orleans.

  • WaterChina’s Mekong River dams undermine neighbors’ economies, food production

    Five Chinese dams on the Mekong River’s upper portions have caused rapid changes in water level, and other adverse effects, downstream, especially in Vietnam, Cambodia, Thailand, and Laos, where millions of people rely on the river for water, food, and transportation

  • InfrastructureDutch test-levee experiment helps strengthen U.S. levees, dams

    In the United States, the national flood-control infrastructure is aging and its structural health is deteriorating; the system comprises more than 5,600 km of levees, and 43 percent of the U.S. population lives in counties with levees designed to provide some level of protection from flooding; some of these levees are as old as 150 years; in 2009, the American Society of Civil Engineers Report Card for America’s Infrastructure gave the condition of the nation’s dams a grade of D, and levees a grade of D-minus; an dam-strength experiment in the Netherland helps engineers collect data to validate new suite of technologies for assessing the health of levees and dams

  • Infrastructure protectionNew earthquake assessment finds increased risk for Washington Dams

    Central Washington state has always been considered low risk for earthquakes back when big hydropower dams went up on the Columbia River many decades ago; a recently completed seismic hazard assessment, however, shows that there is a much greater earthquake potential for the area than previously thought; now, dam owners have to figure out whether their dams can hold up to an earthquake; if retrofits are needed, they could cost hundreds of millions of dollars

  • Infrastructure protectionLocal officials oppose “unacceptable” levee ratings

    In recent years as part of an effort to bolster the nation’s flood protection infrastructure, the Army Corps of Engineers has analyzed and declared more than 200 levee systems across the country as “unacceptable,” resulting in a firestorm of criticism from local officials