About 63 percent of all dams in the U.S. are private enterprises, with state and local governments overseeing the rest. Federal and state governments both have responsibilities for dam safety. States regulate private dams, but most have insufficient regulatory authority. Alabama, for example, has no dam safety regulatory program, while California has a well-funded program with highly-skilled staff. But even states with robust programs are lacking in regulatory authority.
Non powered dams
For two decades, the primary hydropower development activity in the United States has been the retrofitting of existing non-powered dams. There are currently 58 of these dams, with a total capacity of 888 megawatts. This article reviews the development trends for these non powered dams, and discusses the types of strategies that have been adopted to maximize their potential to generate energy. This research will also provide insight into the role of environmental mitigation and market drivers.
Existing approaches to classification have largely omitted key information about dam characteristics. While these datasets do provide some insight, many are incomplete, and do not account for certain factors. A comprehensive approach would require identifying required characteristics and combining disparate data sets, as well as setting appropriate thresholds and discrete classes. Once data on NPDs are gathered, stakeholders would be able to focus on similar groups of dams.
According to the U.S. Department of Energy, US hydropower plants generate 51% of the nation’s renewable energy output. The nation ranks as the fourth largest hydropower player in the world. In 2012, it produced 78GW of conventional hydropower, and 22GW of pumped-storage hydropower. Using these resources to generate energy would provide electricity to more than a million homes and thousands of jobs.
Large steel dams
Ash Fork Bainbridge Steel Dam: This massive structure was built in 1898 by the Atchison, Topeka and Santa Fe Railway. It provided water to their Ash Fork, Arizona, operations, and was the first large steel dam in the world. Located near Ash Fork, Arizona, the dam was named after its civil engineer, Francis H. Bainbridge. The dam was completed by the end of 1898.
Redridge Steel Dam: Despite its name, this dam is not even registered as a dam. Its outlet pipes are as open as possible, acting as emergency spillways. In actuality, the dam is actually a rock and timber dam built 200 feet upstream. Although it is over 120 years old, it still holds back 74 acres of water from Lake Superior. For its low maintenance costs, the dams are still in use today.
Ash-Fork Bainbridge Dam: The Ash-Fork Bainbridge Dam in Washington was one of the nation’s largest dams. Made of open-hearth steel, it weighs more than 400,000 pounds. Its rivets are made from wrought iron. When complete, the dam weighs almost half a million pounds. Its history is a fascinating piece of American engineering, and it’s easy to see why it’s so popular today.
Massive storage dams
ResOpsUS maps the storage capacity of the nation’s massive storage reservoirs. The dataset covers 679 dams in the United States and nine in Canada, representing nearly three-quarters of the total storage capacity of the nation’s large reservoirs. The data includes daily records of storage and outflow, elevation, and 46 evaporation estimates. The information is based on data provided by the various agencies involved in dam operations.
Humanity has relied on water for generations, and the future of water seems to promise dramatic changes in supply and availability. It seems inevitable that our current water supplies will not last forever, and we will need to build more dams and store even more. The removal of dams from watersheds will have ramifications for regional groundwater outcomes, food production, energy production, migration, and urbanization. While dams are a necessary tool for protecting our drinking water resources, they also threaten human lives.
The development of massive storage dams is a vital part of the nation’s economic growth, but their legacy is equally significant. The development of large dams was a central strategy for economic growth, and the number of dams in the United States increased from 5,000 in 1950 to more than four thousand in 2000. Developed countries were particularly affected, but protests halted development after the 1990s. The World Commissions on Dams published a report claiming that the social and environmental costs outweighed the benefits. Yet, in recent years, we’ve seen a new wave of large dam development worldwide.
Usurpation of native lands
The construction of many of the United States’ largest dams encroached on Native land. The Oahe Dam, for example, destroyed more Native land than any other public works project in American history. Its reservoir stretches 250 miles and flooded 90 percent of the timber and bottomland of the Standing Rock and Cheyenne River Nation. The Big Bend Dam flooded 121,026 acres of tribal land. The Crow Creek reservation was submerged and all of the bottomlands of the Missouri Valley.
The United States government sought control of the Columbia River system. The dams had several benefits, but also came with costs. Native People were displaced from their traditional lands, which were once a rich source of food and fiber. Native people wore traditional regalia to witness the flood, and would have stayed to watch. Moreover, the dams disrupted seasonal fish runs and affected orchard-based agriculture. Peach and Plum Orchards, for example, were developed along the Columbia River to take advantage of river irrigation. These orchards have since disappeared beneath the rising waters of Lake Roosevelt.
As the government’s role in determining the location of dams in indigenous areas is largely limited to making decisions about natural resources in the United States, indigenous peoples are particularly vulnerable to dam construction. In 1993, courts in Brazil began granting judgments against indigenous peoples. Since then, the federal government has instituted a series of landmark cases to protect indigenous peoples from the threat of dam construction.
Impact of climate change on dams
The main challenges of evaluating climate change impacts on dams in the United States include the need to assign probabilities to uncertain future conditions and the potential costs of disruption events and failure modes. Different methodologies are needed to analyze the effects of climate change on dams. In this paper, we summarize the main impacts of climate change on each component of dam risk. The results show that a significant proportion of these impacts are not directly related to dam failure.
While dams have been a major source of renewable energy and water storage, they also worsen the impact of climate change, releasing greenhouse gasses into the atmosphere and destroying wetlands, which are important carbon sinks. In addition to causing water shortages and floods, dams also contribute to climate change by increasing sea levels and destroying habitats. Many dams are poorly maintained, putting local governments under considerable financial strain.
Dams are an important economic infrastructure and reflect billions of dollars in investments worldwide. Most large reservoirs in the United States were constructed for hydroelectric power generation, water supply, flood risk reduction, or both. Despite this, dams are perceived as multi-use infrastructures, with 32% of dams serving primarily recreational purposes. Furthermore, reservoirs are located in all states of the U.S.
Economic impacts of dam removal
The economic impacts of dam removal have been a topic of much debate for decades. While dam removal may be expensive, the economic benefits are often much greater. By eliminating the costs and benefits of maintaining dams, dam removal can benefit local economies and the environment. While dam removal is often funded by local governments, various agencies are beginning to recognize the benefits of dam removal. Here are some of the economic benefits of dam removal.
A dam has many benefits and costs, and these benefits and costs are rarely reflected in the economic analysis itself. The economic impacts of dam removal extend well beyond the impact on fish and forests. This decision will also affect jobs and incomes for coastal communities, owls, and timber workers. It is important to consider all of these economic consequences. And don’t forget that the benefits and costs are not evenly distributed.
Depending on the dam’s age, its size, and its location, dam removal can cost $300 million to $1 billion in 1998. The Corps’ estimates for passive use values are also much lower. As a result, the economic impacts of dam removal in the United States are often less than one percent of the region’s total personal income. Regardless of the reasons for dam removal, the public benefits are large enough to offset any individual costs. Restoring a river’s natural habitat, reducing the extinction of wild salmon, and a return to natural balance are all great public benefits.