Dams are an important infrastructure that in some cases prevents seasonal flooding damage, as was the intention of the Teton Dam near Rexburg, Idaho. Built by the United States Bureau of Reclamation, the embankment dam was cheap to construct but failed in early June 1976. Some scientists have hypothesized that this failure was caused by wet seams that may have been present on the right abutment, as they were found on the left abutment following the collapse. Wet seams are seepage zones between the embankment and the sides of the valley (Leonards and Davidson, 1984). This is one of many theories and factors that led to the failure of the Teton Dam, and whether or not this could have been prevented has yet to be determined. However, research …show more content…
into this has provided enlightenment with the hopes that it may prevent failures of similarly constructed dams worldwide. Background: The Teton Dam was built into the steep-walled canyon carved by the Teton River, in eastern Idaho near the city of Rexburg by the United States Bureau of Reclamation (Smalley, 1992).
Planning first began in the 1930s, however, it was stonewalled by environmentalists who believed that it would cause more harm than good to erect this dam in the tentative location and filed multiple lawsuits against the Bureau (Hyndman and Hyndman, 2011). Congress, after the dismissal of the complaints, approved the project in 1964 and eight years later construction began (Gunn, 2006; Hyndman and Hyndman, 2011). The purpose of the dam was not only for providing irrigation water and hydroelectric power to eastern Idaho, as the soil is rich in minerals that makes for good farming, but for recreational purposes and flood control (Hyndman and Hyndman, 2011; Smalley, 1992). The annual spring flooding caused extensive damage, and the Bureau of Reclamation proposed this as the only practical means of controlling it (US Gov., 1976). The Teton Dam was completed in October 1975, and filling of the reservoir began almost immediately at approximately one foot of water per day (Hyndman and Hyndman, 2011; Seed and Duncan, 1987). Statistically the dam was 126 meters high, and 950 meters long and was set to hold 7650000 cubic meters of water (Smalley, 1992). It was a five zoned embankment with a compacted, centralized core built with the silt deposits near the site, as it had “good strength characteristics and …show more content…
low permeability” (US Gov, 1976; Smalley, 1992; Seed and Duncan, 1987, p.175). The spring of 1976 had excessive runoff causing delays in the schedule of filling the reservoir, so in May it went from one foot of water per day to three to four feet of water per day (Seed and Duncan, 1987). On June 3, small springs began forming in the riverbed downstream from the Teton Dam, and by June 5 the water in the reservoir was three feet below the spillway crest (Seed and Duncan, 1987). It was then that a small seepage was observed by the engineers on site who attempted to fill it in to keep it from collapsing, but at approximately noon the right abutment broke spilling millions of cubic meters of water (Smalley, 1992; Hyndman and Hyndman, 2011; Balloffet and Scheffler, 1982). Figure 1: time lapse of the events that occurred on June 5, 1976 at the Teton Dam in eastern Idaho, United States. A. At 11:20am, out of the right abutment, water begins to pour out; B. at 11:55am, right abutment begins to collapse, and a large volume of water pours through the dam; C. and D. taken just after noon, as the dam fails and the reservoir floods through it (Hyndman and Hyndman, 2011, p. 380). The flood was at most eight miles wide traveling at speeds of zero to fifteen miles per hour, killing fourteen people and 13,000 livestock, and forced thousands to become homeless (Balloffet and Scheffler, 1982; Gunn, 2006; US Gov., 1976). In total, this “manmade disaster” cost the federal government about $1.2 billion (2010 dollars), and President Ford declared this a disaster zone (US Gov., 1976; Hyndman and Hyndman, 2011; Gunn, 2006). This catastrophic event “marked the end of large dam building in the United States,” and three days of testimony was heard before the House of Representatives in August 1976 to discuss this matter (Hyndman and Hyndman, 2011; US Gov., 1976). Factors That Led to Failure: While no select group or individual was at fault in causing the collapse of the right abutment of the Teton Dam, there were both geologic and engineering shortcomings that aided in this outcome. However, it is generally agreed upon that the failure was caused by seepage in the zone 1, or central zone, embankment, created by erosion of materials (Sherard, 1987b) During construction, geologists determined that the rock on one side of the canyon walls was weaker than the other and posed the thought that it may break under the added pressure of the water (Gunn, 2006). The walls of the canyon date to the Tertiary, and are made of volcanic rhyolite welded-tuff that has an extensive joint system, and has minor inclusions of basalt and breccia (Seed and Duncan, 1987; Smalley, 1992). The silt deposits used in the embankment were brittle and very erodible, not at all suitable for the dam core, which eventually opened cracks within the Teton Dam leading to its demise (Seed and Duncan, 1987; Smalley, 1992; Sherard, 1987b). When samples from zone 1 were tested they had a similar gradation and plastic limits with the plasticity index ranging from cohesiveless to slightly cohesive and the high content of silt had low plasticity (Sherard, 1987a). In the right and left abutments key trenches wide fissures, voids and caverns were discovered during construction of the Dam, and they “were essentially isolated from the main dam embankment construction operations” (US Gov., 1976, p.243). Three years were spent on the left side, and one and a half years were spent on the right after discovery to treat them before progress in those areas was completed (US Gov., 1976). Leonards and Davidson (1984) stated that “it is agreed that plugging of open joints in the bedrock and filtering of zone 1 core material should have been provided for,” yet this was not fully cared for during construction as the filling material used, silt, calcite and rubble, was not tested for their resistance to water pressure (Smalley, 1992; Gunn, 2006). There were no provisions in place to prevent the erosion of the filling materials and the dam core, so if it had not failed when it did it inevitability would have because of erosion (Sherard, 1987b). These shortcomings, both in the engineering of the dam’s structure and geologically, led to the failure of the Teton Dam. The wet seams caused by the opening of joints downstream as the materials of the dam were weathered and eroded away led to the catastrophic manmade disaster; however, the impact of each factor is undeterminable in the larger scheme of things. Steps in Prevention: While it is impossible to know whether or not this tragedy could have been prevented, there are several things that could have been done to impact the outcome. Hyndman and Hyndman (2011), implicated that having the dam fail when it did was the best possible situation since engineers were still on site and were able to witness the changes in the Teton Dam and warn the surrounding area. With this warning many people were able to escape to higher elevations and out of the flood’s path as it swept through the area, limiting the number of deaths that ensued. If the Teton Dam collapsed after the initial filling and the engineers having left the site, and according to Sherard (1987a), there were no instruments in place at the dam site to predict a failure which could have resulted in an even larger disaster. Furthermore, he suggested that filling the reservoir at the recommended rate of one foot of water per day may have allowed for adjustments within the dam (Sherard, 1987a). The added pressure from the water against the embankment, would need to be attuned for but the increased rate of three to four feet of water per day did not allot enough time for this to occur. The weight of the water on the valley floor also needs to be accounted for as it needs time for consolidation in order to limit the amount of erosion that may take place as a result. Another prevention measure was recommended by the Interior Review Group (IRG), prior to the collapse and afterwards when they investigated the site, that the grout curtain that underlies the dam should have received further testing (Seed and Duncan, 1987). The grout curtain was put into place below zone 1 with the theory that it would prevent seepage under the dam, but the curtain was not fully tested especially with properties of the silt that composes the dam (Smalley, 1992). Overall, these simple methods and extra steps may have prevented the collapse of the dam, or at least predicted it sooner. Discussion: Lessons Learned The collapse of Teton Dam was a catastrophic, manmade disaster, but nevertheless several lessons were learned from this event which has led to more actions involving dams throughout the United States.
The federal government has taken action in requiring “each federal agency to review its dam-safety activities and to strengthen its dam safety programs” (Gunn, 2006). Dams are now required to be inspected annually, with a detailed report of the dam every three years (Gunn, 2006). Moreover, “Congress passed several acts authorizing a natural dam-safety program” which works to protect Americans from dam failure, in addition to installing more instrumentation to monitor the dam’s stability (Gunn, 2006). Sherard (1987b) proposes that having bureaucracies design dams is dangerous and should be avoided; Seed and Duncan (1987) added that it should be reviewed by an outside group of engineers to ensure that no possible design flaw has been over looked. The Teton Dam was an inadequate and unacceptably designed for this environment, and any unanticipated conditions and problems with materials, such as low quality, should be taken into account (Sherard, 1987b; Seed and Duncan, 1987). The wet seam was a new discovery and a lesson in the hydrogeologic properties that were a result of the situation created by the Teton Dam (Sherard, 1987b). An additional lesson is that filling the reservoir at the recommended speed, in controlled conditions is essential, so that it is possible to lower the
water level if problems were to develop (Seed and Duncan, 1987). Had the Teton Dam, not exceeded the one foot per day advised speed it is possible that there would have been more control over the situation. Finally, it is “impossible to provide a tight grout curtain in highly jointed rock with a single row of grout holes” which was the case for the Teton Dam, and “it is equally difficult to seal all rock defects near the rock surface” (Seed and Duncan, 1987). Without digging up the entire valley it was impossible to know all of the faults, joints and features that were below the surface of what would become the Dam floor, however a better understanding of what was there to adequately fill in the problem would have been the best use of their time to avoid this. Nevertheless, the federal government, engineers and geologists acquired a new found knowledge from the failure of the Teton Dam. Conclusion: The Teton dam failure on June 5 changed not only the landscape but the lives of those who were impacted by the flood. The earthen embankment dam built in eastern Idaho, failed due to many factors but specifically wet seams, a new discovery. The wet seams indicated that erosion of the silt was taking place allowing water to escape through joints below the dam to downstream where they could be observed by the engineers and geologist on site. While this was the best case scenario for the failure, as the neighboring people were able to be warned, it caused tremendous damage. Factors that led to this failure included using highly erodible materials, wet seams, poor construction and design for this area, and the lack of provided prevention methods that may have eliminated the erosion. Still, lessons were learned from the collapse of the Teton Dam including yearly inspections of dams, control over filling, and testing of materials of erodibility before using them in an embankment dam such as this. Overall, the failure of the Teton Dam while disastrous provided information for future infrastructure in the United States and around the world.
There are nine dams in and directly leading to New York State’s Letchworth State Park. These dams have been built for a variety of reasons and affect nearly 400 miles of freshwater rivers in the Genesee River Basin of Western New York (Fish, n.d.).
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In December 1936 the United States Department of the Interior authorized the Lower Colorado River Authority to construct a low dam at the site of an old crossing on the river known as Marshall Ford. Marshall Ford Dam was completed in 1941 through the collaboration of the United States Bureau of Reclamation (USBR) and the Lower Colorado River Authority (LCRA) of Texas. The original purpose of the dam was to prevent floods from devastating Austin, TX. The capital city had substandard heavy damage from previous floods since its establishment in 1846. Soon bureaucrats came together to create the Colorado River Project, wanting to create a series of dams along the Colorado River to create hydroelectric power and serve to control floods and droughts. With Buchanan dam well under way with a total of six planned Marshall Ford was the only dam designed primarily for flood control and the only dam in which USBR oversaw construction. With money scarce there was debate over the final height dam and it reservoir capacity. This issue resolves itself with the flood of 1938. Once completed Marshall Ford Dam would flood 65 miles of the Colorado to form Lake Travis, creating the largest of the seven reservoirs known as the Highland Lakes.
Federal Emergency Management Agency’s article, “Benefit of Dams” (2012) analyzes how dams prevent flooding by releasing the excess water in controlled amounts through floodgates (¶ 3).
The one feature common to the Hoover Dam, The Mississippi river and the three gorges dam is that they all tried to control nature’s swings, specifically in the form of flooding. Before the Hoover dam was built, the Colorado river “used to flood spectacularly…but after 1900 the Colorado provoked a vehement response” (Pg 177). The response was simple, but large. The U.S. built several large dams, including the Hoover dam, on the Colorado to decrease its flooding and increase power and irrigation. Unfortunately, just as human control of the Colorado’s flooding increased, its organisms and habitats were detrimentally influenced, and the water became more and more salinated.
As dams became old and upkeep costs rose many were torn down. This allowed the river to flow freely again and the salmon population increased by 20%. It was discovered that the best way to increase the diminishing salmon population was to simply restore the rivers to their original state. In 2008, a judge ordered for the Columbia and Snake River dams to spill water, allowing the rivers to flow as they would naturally. This water flow allowed the salmon to swim along the currents, as they would have once done
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The South Fork Dam collapsed and unleashed 20 million tons of water from its reservoir. A wall of water, reaching up to 70 feet high, swept 14 miles down the Little Conemaugh River Valley, carrying away steel mills, houses, livestock and people. At 4:07 p.m., the floodwaters rushed into the industrial city of Johnstown, crushing houses and downtown businesses in a whirlpool that lasted 10 minutes. (New York Times, 1889).
Congress to delete Echo Park Dam from the Colorado River Project in 1955. Other projects
Over the years Glen Canyon Dam has been the spark for hundreds of debates, rallies, and protests. These debates have been going on for almost forty years now. The fact is that the dam created a huge lake when it was built, this is what bothers environmentalists. This lake is called Lake Powell and thousands of people depend on its tourists for income. The lake also filled up a canyon called Glen Canyon, some people say it was the most beautiful place on earth. The anti-dam side of the debate has its basis in the fact that Lake Powell is currently covering Glen Canyon. It was very remote so few people got to witness its splendor. This is probably the reason the dam was built in the first place, ignorance.
The state offered to sell the canal, the railroad company bought it for the right of ways yet had no need to maintain the dam, which due to neglect, broke for the first time in 1862. McCullough stresses that man was responsible for the dam and its weaknesses nearly thirty years before the great flood as he explains how the initial repair work was carried out by unqualified people and how the discharge pipes were blocked up.... ... middle of paper ... ... McCullough makes a firm argument for the responsibility of man, and asserts the blame on the necessary people, therefore I feel he makes a fair and accurate assertion which I would agree with.
Most of the destructions from the events of August 29th 2005, when Katrina Hit the City Of New Orleans, were not only caused by the storm itself; but also, by failure of the engineering of the levee system protecting the entire infrastructure of the city. The years of poor decision making and avoidance of the levee system led to one of the most catastrophic events in the history of the United States. Throughout our research, we have identified three key players in charge of the levee system design, construction and maintenance. These three organizations are the Unites States Corps of Engineers, the New Orleans Levee District and the Louisiana Department of Transportation. The consequences of the hurricane showed the organizations negligence in the design, construction and maintenance of the protective walls. Later independent sresearch showed that more than 50 levees and food walls failed during the passage of the hurricane. This failure caused the flooding of most of New Orleans and all of ST. Bernard Parish. The Unites States Corps of Engineers had been in charge of the of the levee system and flood walls construction since the 1936 flood act. According to the law, the Louisiana Department of Transportation is in charge to inspect the overall design and engineering practices implemented in the construction of the system. Once the levee systems were finished, they were handed over to the New Orleans Levee District for regular maintenance and periodically inspections. The uncoordinated actions of these three agencies resulted in the complete failure of a system that was supposed to protect the people of New Orleans. The evidence is clear that this catastrophic event did not happened by chance. The uncoordinated response of these...
The fallout of the 1927 flood demonstrates the one of many continuing struggle in dominating the Mississippi River despite understanding the true nature of the river. For example, “The average gauge readings through the last three months of 1926… of the three largest rivers… was the highest ever known… no one at the Weather Bureau or the Mississippi River Commission correlated or even compiled this information” (pg 175). The failure in understand the nature of the river prelude to more elaborate control schemes by expanding the federal government’s responsibility in seizing full control of the Mississippi River from states jurisdiction. The U.S Army Corps of Engineers is fully responsible in constructing va...
Dams made from dirt are very weak and the South Fork dam was built entirely with dirt. From an engineering standpoint dams made with dirt needed to be built ...