142-549: Glen Canyon Dam is a concrete arch-gravity dam in the southwestern United States , located on the Colorado River in northern Arizona , near the city of Page . The 710-foot-high (220 m) dam was built by the Bureau of Reclamation (USBR) from 1956 to 1966 and forms Lake Powell , one of the largest man-made reservoirs in the U.S. with a capacity of more than 25 million acre-feet (31 km). The dam
284-542: A cult following after its publication and established Glen Canyon Dam as a poster child of environmental destruction caused by dams. Abbey's book is discussed in Ecospeak: Rhetoric and Environmental Politics in America (1992) by Jimmie Killingsworth and Jacqueline Palmer, who write that Glen Canyon Dam became "the big symbol of all that blocked freedom in the interests of civilized progress." On March 21, 1981,
426-479: A strike because of a wage reduction due to the completion of public facilities at Page. In December 1959, wages were raised by $ 4 a day, quelling the strikers. Concrete placement started on June 16, 1960, and started at a sluggish but growing pace. In 1962 the workforce topped out at nearly 2,500 employees laboring on the dam. Construction would ultimately claim eighteen lives and injure numerous other workers, but contrary to popular myth, no workers were buried alive in
568-459: A 1983 study by Larry J. Paulson of the University of Nevada showed that the cold water discharge from Glen Canyon Dam has led to a significant reduction of the water temperature, and thus evaporation, from Lake Mead. Arch-gravity dam An arch-gravity dam or arched dam is a dam with the characteristics of both an arch dam and a gravity dam . It is a dam that curves upstream in
710-659: A Presidential election in Imperial County was George H. W. Bush in the 1988 United States presidential election . On November 4, 2008, Imperial County voted 69.7% for Proposition 8, which amended the California Constitution to ban same-sex marriages, showing more support for the proposition than any other strongly Democratic county. Imperial County is in California's 51st congressional district , represented by Democrat Sara Jacobs . In
852-618: A candle to Glen." Emboldened by Echo Park and desperate to prevent the Grand Canyon from reaching the same fate as Glen, Brower and the Sierra Club directed attention towards the proposed Bridge and Marble dams. The Sierra Club launched an extensive publicity campaign to sway public opinion against the plan; in response to the USBR's argument that new reservoirs would open up the Grand Canyon to recreational boaters as Lake Powell had,
994-481: A capacity equal to almost two years' annual flow of the Colorado River, engineers were aware that Lake Powell would be difficult to fill, but more problems were encountered than expected. The original plan was to fill Lake Powell to 3,490 feet (1,060 m) above sea level, the minimum level necessary to generate hydroelectric power by late 1964, after which water would be released down to Lake Mead , with only
1136-710: A dam on the Colorado River at Glen Canyon, several dams on the Gunnison River and San Juan River , and a pair of dams to be built on the Green River , the Colorado's major upper tributary, at Echo Park and Split Mountain. The 1956 Colorado River Storage Project Act authorized the purposes of "regulating the flow of the Colorado River, storing water for beneficial consumptive use, providing for reclamation of arid and semi-arid lands, providing flood control, and generating hydropower." The proposal for Glen Canyon Dam
1278-493: A dam upstream at Flaming Gorge , and increasing the size of the proposed dam at Glen Canyon to replace the storage that would have been provided by Echo Park. A common misconception is that the environmentalists were given a choice between damming Echo Park and damming Glen Canyon, but the USBR "had always planned to build a dam at Glen Canyon, regardless of the outcome of the Echo Park debate". [The Colorado River without dams]
1420-726: A dumpout point for the overflow and drainage from the IID canal system and ditch drainage) and the Algodones Dunes . The New River and the Alamo River flow from the border city of Mexicali northward to the Salton Sea. Another popular destination is the Salton Sea mud pots and volcanoes . These mud pots and volcanoes are in an open field on the eastern side of the Salton Sea. The mud is just above ambient temperature and it
1562-661: A full-page advertisement in the New York Times ran the slogan: "Should we also flood the Sistine Chapel so tourists can float nearer the ceiling?" Faced with public outcry, the Bureau abandoned its Grand Canyon dams, effectively terminating most of the Pacific Southwest Water Plan, in 1968. The coal-fired Navajo Generating Station was built near Page, to make up for the electric power that
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#17327652129081704-585: A green oasis, contrasting with the surrounding desert mountains. It is a refuge and breeding area for migratory birds and local desert wildlife. The Sonny Bono Salton Sea National Wildlife Refuge , 40 miles (60 km) north of the Mexican border at the southern end of the Salton Sea and situated along the Pacific Flyway , is the only refuge of its kind, just 227 feet (69 m) below sea level. Because of its southern latitude, elevation and location in
1846-469: A haphazardly organized trailer park that grew with the workforce. During the construction of the Glen Canyon Bridge, the USBR also began planning a company town to house the workers. This resulted in the town of Page, Arizona , named for former Reclamation Commissioner John C. Page. By 1959, Page had a host of temporary buildings, electricity, and a small school serving workers' children. As
1988-491: A hundred. Imported water and a long growing season allow two crop cycles each year, and the Imperial Valley is a major source of winter fruits and vegetables, cotton, and grain for U.S. and international markets. Alfalfa is another major crop produced in the Imperial Valley. The agricultural lands are served by a constructed agricultural drain system, which conveys surface runoff and subsurface drainage from fields to
2130-427: A level that has not been exceeded since. Just as it seemed inevitable that the dam would fail, inflows fell and the dam was saved. Upon inspection, it was found that cavitation had caused massive gouging damage to both spillways, carrying away thousands of tons of concrete, steel rebar and huge chunks of rock. Repairs to the spillways commenced as soon as possible and continued well into 1984. Air slots were installed at
2272-663: A more serious problem. Construction of the Storage Project, and allowing the Upper Basin to develop its water supplies, would tip the whole Colorado River system toward a structural water deficit since the Colorado River's average flow is less than what was apportioned in the 1922 Compact. The USBR predicted that by 2030 the annual water supply for the Lower Basin would fall by twenty-five percent, to 5.62 million acre-feet (6.93 km). To make up for this deficit,
2414-444: A move that alarmed environmentalists. The environmental organization Sierra Club , led by David Brower , was the most vocal opponent of Echo Park Dam, and fought a protracted battle against the Bureau of Reclamation, on the basis that "building the dam would not only destroy a unique wilderness area, but would set a terrible precedent for exploiting resources in America's national parks and monuments". The Bureau of Reclamation favored
2556-475: A name? We decide to call it Glen Canyon." In addition to its variegated rock formations, Glen Canyon supported a rich riparian zone habitat on the numerous low river terraces formed by the Colorado River, with as many as 316 bird species, 79 plant species and 34 kinds of mammals. In 1963, when construction on the dam was well underway, the Sierra Club published a book on Glen Canyon, The Place No One Knew , featuring photographs by Eliot Porter , and lamenting
2698-406: A narrowing curve that directs most of the water pressure against the canyon rock walls, providing the force to compress the dam. It combines the strengths of two common dam forms and is considered a compromise between the two. They are made of conventional concrete , roller-compacted concrete (RCC), or masonry . Arch-gravity dams are not reinforced except at the spillway . A typical example of
2840-707: A part of the arid regions on the western slope of the Rocky Mountains . The natural course of the river flows from north of Grand Lake, Colorado into the Gulf of California . For many months out of the year, however, no water actually flows from the United States to the gulf, due to human consumption. Imperial Valley users use 3.8km³ of the Colorado River annually Salvation Mountain (location 33°15′14.9″N 115°28′21.4″W / 33.254139°N 115.472611°W / 33.254139; -115.472611 )
2982-557: A shortage in the Lower Basin. The Upper Basin has released 107% of its obligation from Lake Powell since 2000; therefore, falling levels in Lake Mead are a result of water overuse and waste in the Lower Basin states – a "structural deficit". There are also arguments for storing water in Powell: Lake Mead, with its much lower elevation and hotter climate, has a considerably greater evaporation rate than Lake Powell. In addition,
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#17327652129083124-552: A significant overall gain or loss in volume), Lake Powell lost a total of 368,000 acre-feet (0.454 km) to evaporation and only 8,000 acre-feet (0.0099 km) to leakage. During the El Niño winter of 1982–1983 , the Bureau of Reclamation predicted an average runoff for the Colorado River basin based on snowpack measurements in the Rocky Mountains. Snowfall during April and May was exceptionally heavy; this combined with
3266-661: A single man with a three-dollar shovel into that canyon. It was one thing to submit a low-ball bid, but it was quite another to pay for the privilege of breaking the company's back. —Russell Martin, A Story That Stands Like A Dam (1990) With the Colorado River safely diverted around the canyon, construction could begin on the actual concrete arch dam. The contract was given to the Merritt-Chapman & Scott Corporation for an "astoundingly low" $ 107,955,552, about $ 30 million less than USBR's own estimate. Then, right before construction began, about 750 workers organized
3408-505: A sudden rise in temperatures and unusual rainstorms in June to produce major flooding across the western United States. With Lake Powell nearly full, the USBR did not have enough time to draw down the reservoir to accommodate extra runoff. By mid-June, water was pouring into Lake Powell at over 120,000 cubic feet per second (3,400 m/s). Even with the power plant and river outlet works running at full capacity, Lake Powell continued to rise to
3550-483: Is a colorful artificial mountain north of Calipatria, California , near Slab City . It is made from adobe, straw, and thousands of gallons of paint. It was created by Leonard Knight to convey the message that "God Loves Everyone". Mr. Knight refused substantial donations of money and labor from supporters who wished to modify his message of universal love to favor or disfavor particular groups. Anza-Borrego Desert State Park , portions of which are in Imperial County,
3692-605: Is a popular activity, with abundant natural habitat and rare species. The Imperial Valley has an array of golf courses . Golf courses are in Holtville, Brawley and El Centro. Fort Yuma is on the banks of the Colorado River in Winterhaven, California . First established after the end of the Mexican–American War in 1848, it was originally in the bottoms near the Colorado River, less than 1-mile (1.6 km) below
3834-548: Is almost entirely below sea level—235 feet (72 m) below at the edge of the Salton Sea. Its hot desert climate is characterized by daily temperature extremes. It was once part of the Gulf of California , from which it was cut off by the dam-like deposits of the Colorado River Delta Fan as it carved out the Grand Canyon . Bordered by sand dunes and barren mountains, it was uninhabited until 1901, when
3976-571: Is home to the California Mid-Winter Fair and Fiesta, which is the local county fair. It is also home to the Imperial Valley Speedway, a 3 ⁄ 8 mile (600 m) race track. The name Algodones Dunes refers to the entire geographic feature, while the administrative designation for that portion managed by the Bureau of Land Management is the "Imperial Sand Dunes Recreation Area" (sometimes called
4118-731: Is in the Colorado Desert section of the Sonoran Desert , with high temperatures and low average rainfall of 3 inches (76 mm) per year, the economy is heavily based on agriculture due to irrigation, which is supplied wholly from the Colorado River via the All-American Canal . Thousands of acres of prime farmland have transformed the desert into one of the most productive farming regions in California with an annual crop production of over $ 1 billion. Agriculture
4260-501: Is known as Mammoth Wash. South of Mammoth Wash is the North Algodones Dunes Wilderness established by the 1994 California Desert Protection Act. This area is closed to motorized use and access is by hiking and horseback. The largest and most heavily used area begins at Highway 78 and continues south just past Interstate 8 . The dune formations occurring in this area are popular in film-making and have been
4402-400: Is low. Exactly how much of this water has potential to return to the reservoir, and how much "disappears" into the ground, is subject to debate. The Bureau of Reclamation projected that once Lake Powell filled, the total bank storage would stabilize at approximately 6 million acre-feet (7.4 km), and henceforth would fluctuate depending on water levels in the reservoir. The actual loss
Glen Canyon Dam - Misplaced Pages Continue
4544-519: Is named for Glen Canyon , a series of deep sandstone gorges now flooded by the reservoir; Lake Powell is named for John Wesley Powell , who in 1869 led the first expedition to traverse the Colorado River's Grand Canyon by boat. A dam in Glen Canyon was studied as early as 1924, but these plans were initially dropped in favor of the Hoover Dam (completed in 1936) which was located in
4686-530: Is possible to walk right up to the vents. The location is host to a number of gray cones reaching heights of six feet (2 m) and depressions filled with bubbling mud. These features are the result of the geothermal activity in the area. Off-roading on ATVs is another popular activity during the winter months. Heber Dunes State Vehicular Recreation Area is south of El Centro and is primarily an off-roading destination. The valley sand dune recreation area draws hundreds of thousands of off-road enthusiasts. Bird-watching
4828-575: Is the county seat . As per the 2020 Census, Imperial County population was 179,702, an increase of 2.96% compared to 2010 population of 174,528. The population density was 41.8 people per square mile (16.1 people per square kilometer). The racial makeup of the county was 85% Hispanic or Latino, 3.3% black or African American, 2.5% Native American, 2.1% Asian, 0.2% Native Hawaiian or Pacific Islander, and 1.7% from two or more races. 65.7% spoke Spanish and 32.3% English as their first language. There were 39,384 households, out of which 46.7% had children under
4970-658: Is the largest industry in the Imperial Valley and accounts for 48% of all employment. An environmental cost is that, south of the canal, the Colorado River no longer flows above ground at all for much of the year into Mexico. A vast system of canals, check dams, and pipelines carry the water all over the valley, a system which forms the Imperial Irrigation District , or IID. The water distribution system includes over 1,400 miles (2,300 km) of canal and with 1,100 miles (1,800 km) of pipeline. The number of canal and pipeline branches number roughly over
5112-465: Is the largest state park in California . 500 miles (800 km) of dirt roads, 12 wilderness areas and miles of hiking trails provide visitors with an opportunity to see the Colorado Desert . The park is named after Spanish explorer Juan Bautista de Anza and the Spanish name borrego, or bighorn sheep . The park features washes, wildflowers, palm groves, cacti and sweeping vistas. Animals inhabiting
5254-413: Is the main airport in the county. It is primarily a general aviation airport with limited commercial flight service. Major regional airports near the county include San Diego International Airport , Palm Springs International Airport , Yuma International Airport , and Mexicali International Airport . Robert A. Heinlein 's science fiction short story " Water Is for Washing " ( Argosy , November 1947)
5396-513: Is useless to anyone ... I've seen all the wild rivers I ever wanted to see. — Floyd Dominy , Bureau of Reclamation Commissioner, 1966 speech Floyd Dominy , commissioner of the Bureau of Reclamation, was a vital figure in pushing the project through Congress and convincing politicians to take a pro-dam stance, and to assuage rising public concerns. Dominy realized that the USBR had considerable political clout in Western states, due to
5538-605: The Black Canyon . By the 1950s, due to rapid population growth in the seven U.S. and two Mexican states comprising the Colorado River Basin, the Bureau of Reclamation deemed the construction of additional reservoirs necessary. The Glen Canyon Dam remains a central issue for modern environmentalist movements. Beginning in the late 1990s, the Sierra Club and other organizations renewed the call to dismantle
5680-444: The Colorado Desert , the refuge experiences some of the highest temperatures in the nation. Daily temperatures from May to October generally exceed 100 °F (38 °C) with temperatures of 116–120 °F (47–49 °C) recorded yearly. The border city of Mexicali, Baja California , Mexico , has museums, a zoo, a sports convention center, and an international airport. Visitors cross by foot or car from Calexico, California in
5822-501: The Colorado River Compact to officially allocate the flow of the Colorado River and its tributaries. Each half of the Colorado River Basin – the Upper Basin, comprising Colorado, New Mexico, Utah and Wyoming – and the Lower Basin, with California and Nevada – was allotted 7.5 million acre-feet (9.3 km) of water annually, and Treaty relating to the utilization of waters of the Colorado and Tijuana Rivers and of
Glen Canyon Dam - Misplaced Pages Continue
5964-492: The Glen Canyon National Recreation Area . In addition to its flooding of the scenic Glen Canyon, the dam's economic justification was questioned by some critics. It became "a catalyst for the modern environmental movement," and was one of the last dams of its size to be built in the United States. The dam has been criticized for the large evaporative losses from Lake Powell and its impact on
6106-534: The Imperial Canal was opened and diverted Colorado River water into the valley through Mexico. Floodwaters in 1905–07 destroyed the irrigation channels and created the Salton Sea now filled by the New River and irrigation run-off. The rivers in the southern part of the Salton Sea river basin flow south to north. The valley is bordered by the Colorado River to the east and, in part, the Salton Sea to
6248-648: The Miocene epoch when the area was underwater. The Painted Gorge , on the eastern side of the Coyote Mountains, consists of sedimentary , metamorphic and igneous rocks . The Imperial National Wildlife Refuge protects wildlife habitat along 30 miles (50 km) of the lower Colorado River in Arizona and California , including the last un-channeled section before the river enters Mexico . The river and its associated backwater lakes and wetlands are
6390-551: The National Park Service to document and recover artifacts of historical cultures along the river. These went to University of Utah historian C. Gregory Crampton and anthropologist Jesse Jennings, and to the Museum of Northern Arizona . Crampton subsequently wrote several books and articles on his findings. The Museum of Northern Arizona funded an expedition by William Miller and Helmut Abt , in coordination with
6532-599: The United States every day. Restaurants and taco stands , pharmacies, bars and dance clubs draw tourists. Many shops and stalls selling Mexican crafts and souvenirs within walking distance from the border. Also US residents get medical and dental services in Mexicali because they tend to be less expensive than those in the United States. Mexico's drinking age of 18 makes it a weekend destination for high school and college-aged Southern Californians. Although this region
6674-510: The arch 's curved design which is effective in supporting the water in narrow, rocky locations where the gorge 's sides are of hard rock and the water is forced into a narrow channel. Therefore, the span needed for the dam is also relatively narrow, and the dam's curved design effectively holds the water back while using less construction material compared to a pure arch dam or gravity dam. These dams are more reliable than arch dams. Typically, arch-gravity dams are built in canyon-like terrain, with
6816-403: The state legislature , the county is in the 56th Assembly District , represented by Democrat Lisa Calderon , and the 40th Senate District , represented by Republican Brian Jones . The median income for a household in the county was $ 31,870, and the median income for a family was $ 35,226. Males had a median income of $ 32,775 versus $ 23,974 for females. The per capita income for
6958-477: The "Glamis Dunes"). The Algodones Sand Dunes are the largest mass of sand dunes in California. This dune system extends for more than 40 miles (60 km) along the eastern edge of the Imperial Valley agricultural region in a band averaging 5 miles (8 km) in width. A major east–west route of the Union Pacific railroad skirts the eastern edge. The dune system is divided into 3 areas. The northernmost area
7100-464: The "virtual faucets" of a Colorado River dam "to be built in what amounted to hostile territory." With the Glen Canyon site out of the question, the initial need for a reservoir was realized in 1936 with the completion of Hoover Dam in Black Canyon, storing 32 million acre-feet (39 km) in the mammoth reservoir of Lake Mead . It was not able to weather the worst floods or droughts, and
7242-529: The 1905 flood, when the Colorado River spilled over and formed the Salton Sea ? But don't be too sure about quakes; valleys below sea level don't just grow—something has to cause them. The San Andreas Fault curls around this valley like a question mark. Just imagine the shake-up it must have taken to drop thousands of square miles below the level of the Pacific. Due to its desert environment and proximity to Los Angeles, California , movies are sometimes filmed in
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#17327652129087384-435: The 2000–2004 Colorado River drought, when the basin experienced its lowest five-year runoff on record, Lake Mead would likely have gone dry and the Lower Basin experienced massive cuts, were it not for releases from Lake Powell. Lake Powell and Lake Mead are currently operated under an "equalization" policy that governs releases from Glen Canyon Dam. In order to maintain hydropower generation at both Glen Canyon and Hoover Dams,
7526-556: The Colorado River Storage Project as a whole, the Bureau of Reclamation dropped the Echo Park proposal in 1954. Even as construction began on the other dams, the drama of the Echo Park debate had shifted the American public's perception on big government projects and their environmental consequences. Echo Park was considered a victory for the American environmental movement, but it only happened in exchange for
7668-457: The Colorado River basin and government officials was that a high dam had to be built on the Colorado to control floods and provide carry-over water storage for times of drought. Possible locations for this dam were debated for years, and the Bureau of Reclamation's first study for a dam at Glen Canyon was made in 1924, in addition to studies for locations at Black and Boulder Canyons lower on the Colorado, below Grand Canyon. These studies found that
7810-439: The Echo Park site over Glen Canyon, because its narrow canyons and high elevation (more than 5,000 feet (1,500 m), as compared to 3,700 feet (1,100 m) at Glen Canyon) would lead to less evaporation. It said that building Echo Park Dam and a "low" Glen Canyon Dam would save 165 thousand acre-feet (0.204 km) of water per year over a "high" Glen Canyon Dam (which was ultimately the version to be built). While studying
7952-460: The Imperial Valley to produce algae fuel with their engineered algae strains, as well as other algae products such as food. The Imperial and Mexicali Valleys share a common international bond of both American and Hispanic cultures. On the U.S. side, the majority of residents are of Mexican-American or Latino heritage, while the Mexican side has been greatly influenced by American culture by
8094-597: The Imperial and Mexicali Valleys. In 2005, the Imperial Valley Mall opened, attracting shoppers from the Valley area, including residents and tourists across the border from Mexicali , greatly contributing to the county's retail sales. Tourism is considered the secondary industry of the Imperial Valley. Many visitors come to the area to visit the Salton Sea (California's largest inland lake, which serves as
8236-554: The Navajo Nation, to investigate historical artifacts. They discovered a petroglyph in the upper part of the canyon depicting the appearance of the Crab Nebula in 1054. In 1956, work began on the two diversion tunnels that would carry the Colorado River around the dam site during construction. Each of the tunnels was 41 feet (12 m) in diameter, with a combined capacity of 200,000 cubic feet per second (5,700 m/s);
8378-472: The Navajo people. The environmental lobby wanted the Bureau of Reclamation to keep Lake Powell at or below a level of 3,600 feet (1,100 m), to prevent it from intruding into the monument. The Bureau of Reclamation proposed to build a barrier dam and pump system in order to keep water out of the monument. With the potential damage that would be caused to the remote environment, "the cure would be far worse than
8520-618: The Pacific Northwest there was a lot of suspicion that the Pacific Southwest Water Plan was merely a smokescreen for a much larger plan, long a gleam in the Colorado Basin's eye, to tap the Columbia River ." ... Echo Park was a pure indulgence in the most austere of deserts. In autumn, its groves of cottonwood and yellowing willow gave it a New England air. In the spring, the swollen Green [River] would flood
8662-530: The Rio Grande was signed in 1944 allocating 1.5 million acre-feet (1.9 km) to Mexico. The third lower basin state, Arizona, did not ratify the Compact until 1944 because it was concerned that California might seek to appropriate a portion of its share before it could be put to use. The total, 16.5 million acre-feet (20.4 km), was based on only thirty years of streamflow records starting in
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#17327652129088804-444: The Salton Sea, which is a designated repository for agricultural runoff, with environmental considerations not yet solved. Imperial Valley has become a "hot-bed" of renewable energy projects, both solar and geothermal. This is driven in part by California's mandate to generate 33% of its electricity from renewable sources by 2020, the valley's excellent sun resources, the high unemployment, its proximity to large population centers on
8946-488: The U.S. for many decades. The entire valley has multi-racial representation of Africans, Europeans, east and south Asians, and Native Americans. The El Centro Metropolitan Area is home to 182,972 residents, according to a 2017 US Census estimate, and encompasses the whole Imperial County. The area is in the far southeast region of the State of California . Major population centers are Brawley , Calexico , and El Centro , which
9088-620: The USBR incorporated these proposals with the "Pacific Southwest Water Plan" on January 21, 1964, in which power sales from Glen, Marble and Bridge (often called "cash register dams") would be used to fund a diversion of water from the wetter Pacific Northwest to the Colorado Basin. In addition to the proposed diversion of the Trinity River in Northern California, Marc Reisner wrote in Cadillac Desert that "in
9230-489: The Upper Basin states risked a "call" on the Colorado River during drought years: they would be forced to use less water in order to keep the river flowing to Lake Mead and California, the state with the most senior water rights. To provide water for the Upper Basin and ensure delivery to the Lower Basin, the Bureau of Reclamation proposed the Colorado River Storage Project , which would consist of
9372-545: The West, it is said, water flows uphill towards money." In a 2011 interview, Floyd Dominy , the Reclamation Commissioner who had spearheaded the Colorado River Storage Project, maintained USBR's stance on the benefits of the dam project. Although Lake Powell loses water to evaporation and leakage, it continues to serve an important function capturing runoff during wet years, as "insurance" for droughts. During
9514-417: The age of 18 living with them, 57.7% were married couples living together, 17.1% had a female householder with no husband present, and 20.1% were non-families. 17.1% of all households were made up of individuals, and 8.1% had someone living alone who was 65 years of age or older. The average household size was 3.33 and the average family size was 3.77. In the county the population was spread out, with 31.4% under
9656-465: The age of 18, 9.9% from 18 to 24, 30.4% from 25 to 44, 18.2% from 45 to 64, and 10.0% who were 65 years of age or older. The median age was 31 years. For every 100 females, there were 109.3 males. For every 100 females age 18 and over, there were 111.4 males. Imperial County is a Democratic stronghold in Presidential, Congressional, and local elections. The last Republican to have won a majority in
9798-400: The bottom of each spillway to break up and absorb the shock of the bubbles formed by cavitation. In 1984, the Colorado River basin produced even more runoff than 1983, peaking at 148,000 cubic feet per second (4,200 m/s) in early June. This time, the USBR had drawn down the reservoir enough that it absorbed most of the early high flows. Nevertheless, Lake Powell rapidly approached the top of
9940-478: The bottom of the canyon, in sharp contrast to the roaring rapids upstream in Cataract Canyon and downstream in the Grand Canyon. After his groundbreaking 1869 expedition , John Wesley Powell had named Glen Canyon for its characteristics: "So we have a curious ensemble of wonderful features – carved walls, royal arches, glens, alcove gulches, mounds and monuments. From which of these features shall we select
10082-401: The canyon bottom and leave lush meadows as it went. Echo Park was probably the most beautiful canyon flat in all of Utah, part of Dinosaur National Monument. It was also an ideal site for a dam. — Marc Reisner , Cadillac Desert (1986) The Echo Park dam would be inside the federally protected Dinosaur National Monument and would submerge 110 miles (180 km) of scenic canyons –
10224-561: The canyon to the other. A road link was urgently needed, in order to safely accommodate workers and heavy construction equipment. The contract for building the bridge was awarded to Peter Kiewit Sons and the Judson Pacific Murphy Co. for $ 4 million and construction began in late 1956, reaching completion on August 11, 1957. When finished, the steel arch Glen Canyon Bridge was itself a marvel of engineering: at 1,271 feet (387 m) long and rising 700 feet (210 m) above
10366-426: The center of shipping exports as well as being home to retail, transportation, wholesale, and agricultural industries. There are also two international border crossings nearby for commercial and noncommercial vehicles. The city's population was 37,835 at the 2000 census and 42,598 at the 2010 census. The city is 50 feet (20 m) below sea level and the largest city in the United States below sea level. Fifty percent of
10508-511: The city grew, it gathered additional features, including numerous stores, a hospital, and even a jeweler. It was intended to serve a maximum population of eight thousand, accounting for the workers' families; the peak workforce would eventually exceed 2,500 in the busiest phases of construction. The engineer in charge of the project would be Lem F. Wylie , who had worked on Hoover Dam and had previously designed six other USBR dams. Prior to and during construction, three separate grants were issued by
10650-655: The city of El Centro . The Valley is bordered by the Colorado River to the east and, in part, the Salton Sea to the west. Farther west lies the San Diego and Imperial County border. To the north is the Coachella Valley region of Riverside County , which together with Imperial Valley form the Salton Trough , or the Cahuilla Basin, also the county line of Imperial and Riverside counties, and to
10792-482: The closest paved road, U.S. Route 89 – a new road had to be constructed, branching off from US 89 north of Flagstaff, Arizona , and running through the dam site to its terminus at Kanab, Utah . Because of the isolated location, acquiring the land at the dam and reservoir sites was not particularly difficult, but there were a few disputes with ranchers and miners in the area (many of the Navajo Nation ). Much of
10934-544: The coast, and large tracts of undeveloped desert land. Much of the land suitable for green energy is owned by the federal government ( Bureau of Land Management ). As of April 2008 , the BLM has received 163 applications to build renewable energy projects on 1,600,000 acres (6,500 km ) in California, "almost all of them are planned for the Imperial Valley and the desert region north of the valley." In addition, in 2012 Synthetic Genomics bought an 81-acre (33-hectare) site in
11076-582: The concrete. Cement needed to make concrete for the dam came from the Phoenix Cement Company plant constructed for the purpose in Clarkdale , south of Flagstaff . A huge concrete plant capable of putting out 1,450 tons per hour was installed, and a pair of cableways with movable towers (with capacities of 50 and 25 tons respectively) spanned the canyon, carrying the 12-cubic-yard (9.2 m) concrete buckets to their final destinations on
11218-453: The contract for the diversion tunnels in 1956. Transporting workers and equipment to the bottom of the canyon was extremely difficult. Initially, transport was done by barge from Wahweap Creek, but the fast current of the Colorado River could be dangerous. After a barge capsized, spilling tons of machinery into the river, a much safer cable-car system was installed. During excavation, the rock frequently broke apart or "slabbed" and collapsed into
11360-481: The conventional concrete dam is the Hoover Dam . Changuinola Dam is an example of the RCC arch-gravity dam. A gravity dam requires a large volume of internal fill. An arch-gravity dam can be thinner than the pure gravity dam and requires less internal fill. Arch-gravity dams are dams that resist the thrust of water by their weight using the force of gravity and the arch action . An arch-gravity dam incorporates
11502-505: The county was $ 13,239. About 19.4% of families and 22.6% of the population were below the poverty line, including 28.7% of those under age 18 and 13.6% of those age 65 or over. The Imperial Valley has a range of schools including high schools, middle/junior high schools, elementary schools, and colleges. Central Union High School , Southwest High School , Calexico High School , Holtville High School , Imperial High School , Calipatria High School , and Brawley Union High School are some of
11644-486: The current state of the Salton Sea. The cities and communities of the desert region are outliers in that they are away from urbanized Imperial and tend to be smaller in population than the cities surrounding El Centro. Cities of the El Centro area tend to be larger than those of the desert and Salton regions. And the southeastern end of California is the state's poorest region with lower-income residents make up over half of
11786-642: The dam and drain Lake Powell in Lower Glen Canyon. Glen Canyon and Lake Powell are managed by the Department of the Interior within Glen Canyon National Recreation Area . Since first filling to capacity in 1980, Lake Powell water levels have fluctuated greatly depending on water demand and annual runoff. The operation of Glen Canyon Dam helps ensure an equitable distribution of water between
11928-479: The dam was topped out. Work on the power plant and spillways began directly after the dam wall was complete. The spillway tunnels were excavated around both abutments of the dam, dropping steeply from their control gates on Lake Powell to merge with the lower ends of the diversion tunnels. This measure saved cost, but introduced a weak point where the two tunnels intersected. The upper ends of the diversion tunnels were then sealed with solid concrete. The first electricity
12070-501: The disease." The proposal was fought over and litigated for years until it was permanently shelved in 1973. Glen Canyon Dam became the subject of influential literature, including Edward Abbey 's novel The Monkey Wrench Gang (1975), which tells the story of a fictional group of environmentalists fighting against industrial developers in the American Southwest, their ultimate target being Glen Canyon Dam. The novel gained
12212-574: The diversion tunnels. On October 15, 1956, President Dwight D. Eisenhower pressed a button on his desk in Washington, D.C. , sending a telegraph signal that set off the first blast of dynamite at the portal of the right diversion tunnel. Drilling the tunnels through the porous Navajo sandstone abutting the dam site posed major problems for the excavation crews of the Mountain States Construction Company, which won
12354-402: The ecology of the Grand Canyon, which lies downstream; environmental groups continue to advocate for the dam's removal. Water managers and utilities state that the dam is a major source of renewable energy and provides a buffer for severe droughts. The Colorado River is the single largest source of water in the southwestern United States and northwest Mexico; before massive dam projects tamed
12496-519: The economic contributions of its water projects. Reisner wrote that "Dominy cultivated Congress as if he were tending prize-winning orchids ... If some Senator was causing him trouble, money for his project could disappear mighty fast." With the necessary political support secured, the Colorado River Storage Project was authorized in April 1956, and groundbreaking of Glen Canyon Dam began in October of
12638-532: The excess stored in Lake Powell. The spring runoff in 1963 was the lowest on record in ten years. By the beginning of 1964, Lake Powell had barely reached half the target level, and Lake Mead had seen a sharp decline. In March, Secretary of the Interior Stewart Udall ordered the filling halted and extra releases made to Lake Mead, to the consternation of the Upper Basin states. In May, Udall changed his mind yet again to lower releases, gambling that
12780-426: The figures, Brower discovered that the difference should be no more than 19 thousand acre-feet (0.023 km). Although it is unclear whether the discrepancy was due to a miscalculation or intentional manipulation, Brower said "it would be a great mistake [to rely on the Bureau's figures] when they cannot add, subtract, multiply and divide." In the face of public scrutiny, and wishing to avoid more questions about
12922-539: The high schools Imperial Valley has to offer. Imperial Valley College , in Imperial , and SDSU Imperial Valley Extension, in Calexico , are local. The valley also offers a partnership between the local community college, Imperial Valley College, and SDSU's extension which offers a four-year bachelor's degree for students in the area. The program was formally named imperial Valley Partnership University. This partnership
13064-406: The jobs in El Centro come from the service and retail sector. The Imperial Valley often has summer temperatures well over 100 °F (38 °C), but from late October until mid-April the temperature is relatively mild and sometimes low. During winter months the Valley averages more than eight hours of sunshine a day, receiving the most sunlight of any place in the United States . Historically,
13206-451: The lakes must be kept at approximately the same level. By spreading out the water, evaporation is greatly increased. Since the year 2000, Lake Mead has steadily declined toward the critical level at which a shortage would be declared for the Lower Basin states. A plan called "Fill Mead First", which would drain Lake Powell in order to refill Lake Mead, has gained traction in recent years. Glen Canyon Dam would remain in place (as total removal of
13348-447: The land acquired for the dam was through an exchange with the Navajo, in which the tribe ceded Manson Mesa south of the dam site for a similar-sized chunk of land near Aneth, Utah , which the Navajo had long coveted. In the early stages of construction, the only way to cross Glen Canyon was a suspension footbridge made of chicken wire and metal grates. Vehicles had to make a 225-mile (362 km) journey in order to get from one side of
13490-496: The late 1890s. It was believed to represent the annual flow as measured at Lee's Ferry, Arizona (the official dividing point of the upper and lower basins), 16 miles (26 km) downstream of present-day Glen Canyon Dam. As it turned out, the early 20th century was one of the wettest periods in the last 800 years. The dependable natural flow past Lees Ferry is now believed to be about 13.5 to 14.6 million acre-feet (16.7 to 18.0 km). The general consensus among inhabitants of
13632-421: The loss of the canyon before most of the American public had a chance to visit, or were even aware of its existence. Though little known to most Americans before Porter's book, Glen Canyon had been visited by a handful of hikers and boaters (such as Powell's expedition), and some had even been interviewed by Brower. As said to Brower by writer Wallace Stegner , who had been to the canyon in 1947, "Echo doesn't hold
13774-469: The lower Colorado sites had stronger foundation rock which might result in less reservoir seepage. The Glen Canyon site was so remote that delivering supplies and transporting workers there would be infeasible at the time. The first Glen Canyon proposal lay upstream of the Lee's Ferry dividing line, and would be considered the Upper Basin's water. With its substantial Congressional clout, California refused to allow
13916-487: The lower portion of the river. During droughts, there was too little water available for irrigation . In 1904, the Colorado River was accidentally redirected after it damaged a canal gate in Mexico, causing the river to flood part of California's Imperial Valley and create the Salton Sea . After this catastrophe, California and Arizona began to call for a dam to control the tempestuous river. In 1922, six U.S. states signed
14058-417: The lowest minimum temperature ever recorded in the Imperial Valley was 16 °F (−9 °C) on January 22, 1937. The highest maximum temperature ever recorded was 121 °F (49 °C) on July 28, 1995. The lowest maximum temperature was 42 °F (6 °C), recorded on January 24, 1949, and the highest minimum temperature was 92 °F (33 °C) on June 30, 1946. The highest monthly mean temperature
14200-536: The magnitude of 1983. Long after the Glen Canyon Dam was built and continuing to the present day, controversy remains between supporters of dam removal and those who believe it should be left in place. One of the earliest debates regarding the dam was its impact on Rainbow Bridge National Monument , whose 290-foot (88 m) high natural arch is the highest in North America, and is a sacred site to
14342-402: The main reasons for this slow rise, in addition to the need to meet obligations to the Lower Basin, was the leakage of vast amounts of water into the porous Navajo Sandstone aquifer. Between 1963 and 1969, as much as 655,000 acre-feet (0.808 km) leaked into the reservoir banks each year. Conversely, some of this "bank storage" flows back into the reservoir as springs and seeps when Lake Powell
14484-524: The mouth of the Gila River . It was to defend the newly settled community of Yuma, Arizona on the other side of the Colorado River and the nearby Mexican border . In March 1851 the post was moved to a small elevation on the Colorado's west bank, opposite the present city of Yuma, Arizona, on the site of the former Mission Puerto de Purísima Concepción . This site had been occupied by Camp Calhoun, named for John C. Calhoun , established in 1849. Fort Yuma
14626-506: The narrow lower reaches of Glen Canyon shortly upstream of Lee's Ferry. The site originally favored by the USBR was just 4 miles (6.4 km) upstream, but the final decision was to build the dam 16.5 miles (26.6 km) upstream because of stronger foundation rock and easier access to gravel deposits on Wahweap Creek . Because the dam site lay in a remote, rugged area of the Colorado Plateau – more than 30 miles (48 km) from
14768-504: The opportunity to stay local for students in the Imperial Valley, but it has also provided priority registration, scholarship opportunities, and the ability to use resources from both the IVC's and SDSU's campuses. IVUP continues to expand in each academic term and actively does outreach throughout different high schools in the valley by performing presentations and one-on-one interviews with students who express interest. Imperial County Airport
14910-425: The point where the spillways had to be opened. Other than a brief test in 1980, this was the only time the spillways had ever been used. At the beginning of June, dam operators opened the gates on the left spillway, sending 10,000 cubic feet per second (280 m/s), less than one-tenth of capacity, down the tunnel into the river below. After a few days, the entire dam suddenly began to shake violently. The spillway
15052-409: The political forces that resulted in Glen Canyon and hundreds of other dams being built in the 1960s and 1970s. Many of these projects had dubious economic justifications and hidden environmental costs, but the government agencies that built them – namely the Bureau of Reclamation and the U.S. Army Corps of Engineers – were more interested in maintaining their size and influence. Reisner writes that "in
15194-507: The power necessary to pump water to where it was needed in central Arizona. In 1963, Arizona's congressional delegation proposed these dams as part of the Central Arizona Project to accomplish these goals. The state of California opposed the project, as it would eliminate the "surplus" water in the Colorado (really the Upper Basin's yet unused supplies) it had gotten accustomed to using. The Bureau of Reclamation recognized
15336-558: The power to save the place did not. I was within a few feet of his desk in Washington that day and witnessed how the forces long at work had their way. So a steel gate dropped, choking off the flow of the canyon's carotid artery, and from that moment the canyon's life force ebbed quickly. A huge reservoir, absolutely not needed in this century, almost certainly not needed in the next, and conceivably never to be needed at all, began to fill." Construction continued and on September 13, 1963,
15478-466: The radical environmental group Earth First! staged an anti-dam protest by unfurling a 300-foot (91 m) tapered black sheet of plastic down the face of the dam, making it appear as if a gigantic crack had appeared in the structure – a direct re-enactment of a scene from Abbey's book. Authorities were unable to find the individuals responsible. In his comprehensive history of western water development, Cadillac Desert (1986), Marc Reisner criticized
15620-465: The right-side tunnel was 2,740 feet (840 m) long and the left 2,900 feet (880 m). The right tunnel would be used for carrying the Colorado's normal flow around the dam site, while the left tunnel, 33 feet (10 m) above the water, would only be used during floods. The lower reaches of the tunnels would later be used to form the lower ends of the dam's spillways. About 182,000 cubic yards (139,000 m) of material would have to be excavated from
15762-505: The river in the 20th century, its flow was far from dependable. Annual discharge from the Colorado River and its tributaries ranges from 4 to 22 million acre-feet (4.9 to 27.1 km), and 10-year averages may fluctuate as much as 1 million acre-feet (1.2 km). Flooding, and the river's enormous silt or sediment load, created problems for settlements in the Lower Colorado River Valley and navigation on
15904-400: The river, it was the highest bridge of its kind in the United States and one of the highest in the world. The bridge soon became a major tourist attraction. The March 1959 issue of LIFE reported that "motorists [were] driving miles out of their way just to be thrilled by its dizzying height." Workers moved to the dam site beginning in the mid-late 1950s; the construction camp started out as
16046-482: The same year. David Brower visited Glen Canyon shortly after the decision to build the dam, and "realized once he arrived that this was not a place for a reservoir". Glen Canyon's springs, side canyons, and intricately sculpted rock formations were home to such features as Music Temple and Cathedral in the Desert, a giant cave-like natural amphitheater with a waterfall at its center. The Colorado River flowed gently across
16188-450: The site for movies such as Return of the Jedi . The Salton Buttes are volcanoes on the southern shores of the Salton Sea. The Colorado River is a popular destination for water sports including fishing, boating, water-skiing, and jet-skiing. The Colorado River is a river in the southwestern United States and northwestern Mexico, approximately 1,450 miles (2,330 km) long, draining
16330-555: The south the international boundary with Mexico . The culture of the area blends those of the United States and Mexico , due to its regional history and geographic location along the international border. The Imperial Valley economy is based on agriculture. Imperial Valley was named by the Imperial Land Company , in the hopes of attracting settlers. It is now the home of the El Centro metropolitan area . Locally,
16472-538: The southwest portion of Imperial Valley, 4 inches (10 cm) of snow was reported that day. This was the only snowfall on record to cover the entire valley. Imperial Valley can loosely categorize its cities and communities into three regions: the Salton Beach Towns, Desert Cities, and the El Centro area (urbanized Imperial). The Salton Sea Beach Towns have the smallest cities but were resorts in their heyday and have since shrunk in population and size due to
16614-415: The spillway gates and construction efforts were subsequently focused on the left spillway in order to get it in operation in time. On August 12, the left spillway gates were opened, releasing water at a rate of 50,000 cubic feet per second (1,400 m/s). The spillway was undamaged, proving the worth of the re-engineering and suggesting that Glen Canyon Dam will also be able to hold against future floods with
16756-473: The spring runoff would be enough to raise Powell to minimum power pool by autumn, by which time power releases could begin, to prevent Lake Mead from falling below its minimum power pool. That gamble paid off, with Lake Powell barely inching over the 3,490-foot (1,060 m) mark on August 16, 1964. It took more than 17 years for Lake Powell to finally reach its full elevation of 3,700 feet (1,100 m) above sea level, which it crossed on June 22, 1980. One of
16898-485: The state park include greater roadrunners , golden eagles , kit foxes , southern mule deer and Peninsular bighorn sheep , as well as desert iguanas , chuckwallas , and sidewinders . Fossil Canyon and the surrounding area near Ocotillo in the Coyote Mountains are great places for rock hounding and fossil hunting. The fossils here are not dinosaurs, but ancient shells , coral , and oysters from
17040-747: The states of the Upper Colorado River Basin ( Colorado , Wyoming , and most of New Mexico and Utah ) and the Lower Basin ( California , Nevada and most of Arizona ). During years of drought, Glen Canyon guarantees a water delivery to the Lower Basin states, without the need for rationing in the Upper Basin. In wet years, it captures extra runoff for future use. The dam is also a major source of hydroelectricity , averaging over 4 billion kilowatt hours per year. The long and winding Lake Powell, known for its scenic beauty and recreational opportunities including houseboating , fishing and water skiing , attracts millions of tourists each year to
17182-508: The steadily rising crest of the dam. The concrete was poured into modular 7.5-foot (2.3 m) high wooden blocks or "forms", the largest measuring up to 60 feet (18 m) by 210 feet (64 m); more than 3,000 of these blocks made up the main structure of the dam. Once the concrete cured, the wooden scaffolding was removed and shifted upwards to accommodate the next load of concrete. As more efficient methods of concrete pouring were installed, including conveyors and remotely controlled buckets,
17324-414: The structure would be prohibitively expensive), but would only store water in wet seasons when runoff exceeds the capacity of Lake Mead to hold it. Much of the opposition to this plan is along political lines: Lake Powell is legally considered the Upper Basin's water, and Lake Mead belongs to the Lower Basin. The Friends of Lake Powell have called this an attempt to steal water from the Upper Basin, to avoid
17466-502: The surrounding cliffs serving as supporting walls. An arch-shaped bank-fill dam reduces the overall mass of the structure and the cost of construction compared to purely gravity dams. Arch dams and arch-gravity dams are most commonly used in hydraulic structures of more than 100 m in height. Imperial Valley The Imperial Valley ( Spanish : Valle de Imperial or Valle Imperial ) of Southern California lies in Imperial and Riverside counties, with an urban area centered on
17608-489: The terms "Imperial Valley" and "Imperial County" are used synonymously. Imperial Valley is also called Lithium Valley , because of its rich supply of lithium , used to power electric vehicles , cameras, etc. The Imperial Valley extends southward for 50 miles (80 km) from the southern end of the Salton Sea into Mexico . Part of a trough stretching from the Coachella Valley to the Gulf of California , it
17750-480: The tunnels, and metal bolts had to be drilled into the rock to secure it. The largest such event, on August 5, 1958, sent 5,200 cubic yards (4,000 m) crashing down onto the upper portal of the left diversion tunnel. Material dug out of the tunnels and the dam abutments on the canyon walls was used to build the two cofferdams to divert the Colorado River, which were complete in February 1960. The upper cofferdam
17892-466: The west. Farther west lies the border with San Diego County and to the south the international boundary between the US state of California and Baja California , Mexico . To the north is the boundary with Riverside County and the Coachella Valley , which with the Imperial Valley form the "Cahuilla Basin" or the " Salton Trough ". El Centro is the largest industrial center of the Imperial Valley, being
18034-441: The workforce gradually decreased. By late 1962, concrete was being poured into the dam at a rate of 8,000 cubic yards (6,100 m) per day even as the workforce was scaled down to about 1,500. At the beginning of 1963, the dam was high enough to begin impounding water; huge steel gates were closed over the right diversion tunnel on January 21, and Lake Powell began to rise. A minimal flow of 1,000 cubic feet per second (28 m/s)
18176-535: The year-round population. The El Centro , CA MSA is a multicore metropolitan region containing several urban areas . Imperial County's economy consists predominantly of government , agriculture , and retail trade that represents approximately 70% of total county employment. Government services account for over one-third of total employment. Agriculture accounts for one-fourth of jobs with major crops of alfalfa , lettuce , sugar beets and carrots . Retail growth has been experienced due to increased population in
18318-503: Was 13.4 million acre-feet (16.5 km), twice the initial prediction, but river flow data indicates that further leakage after 1980 has been negligible. According to a 2013 study by hydrologist Thomas Myers for the Glen Canyon Institute , the reservoir continues to lose about 380,000 acre-feet (0.47 km) each year due to leakage. According to USBR data for water year 2015 (a year when Lake Powell did not experience
18460-512: Was 168 feet (51 m) high, and it alone could store several million acre-feet of water to protect the dam site from flooding in the event that inflows exceeded the capacity of the diversion tunnels. On February 11, 1959, the right diversion tunnel was completed and began to carry the flow of the Colorado. The left tunnel was finished over three months later on May 19, 1959, slightly behind schedule. It looked as if they [Merritt-Chapman & Scott] were going to start losing money before they dropped
18602-472: Was 95.9 °F (35.5 °C), recorded in August 1969 and the lowest mean temperature was 42.3 °F (5.7 °C) in February 1939. The 85-year average annual rainfall is 2.93 inches (74 mm) with June being the driest month. The only recorded snowfall in the Valley occurred on December 12, 1932. Snow began falling at 8:45 p.m. and by 5 a.m. the next day 2.5 inches (6 cm) had been recorded. In
18744-410: Was allowed through the dam, to prevent the Colorado River from drying up completely. On that day, David Brower confronted President John F. Kennedy in a last-ditch effort to delay Glen Canyon's inundation. Brower later said of that exchange: "On January 2, 1963, the last day on which the execution of one of the planet's greatest scenic antiquities could yet have been spared, the man who theoretically had
18886-401: Was based on the premise that an earthquake had catastrophically shattered the range of deposits separating the Imperial Valley from the Gulf of California , precipitating a tidal wave moving north to transiently drown these lowlands. At the beginning of the story, Heinlein uses the character of a bartender in El Centro to establish the danger of the quake and inundation: You've heard about
19028-404: Was closed down for inspections and workers discovered that the flow of water was causing cavitation – the explosive collapse of vacuum pockets in water moving at high speed – which was damaging the concrete lining and eroding the rock spillway tunnels from the upper ends of the diversion tunnels, which connect to the bottom of the reservoir. This was rapidly being destroyed by the cavitation and it
19170-554: Was established to protect the southern emigrant travel route to California and to attempt control of the warlike Yuma Indians in the surrounding 100-mile (160 km) area. NAF El Centro is the winter home of the U.S. Navy Flight Demonstration Squadron, The Blue Angels . NAF El Centro historically starts the Blue Angels' season with their first air show, traditionally held in March. The Imperial Valley Expo & Fairgrounds
19312-439: Was exhausted; discharges through the left spillway reached 32,000 cubic feet per second (910 m/s), and the right spillway was opened to 15,000 cubic feet per second (420 m/s). At Lee's Ferry, the Colorado River peaked at 97,300 cubic feet per second (2,760 m/s), which was and still is the highest water flow recorded there since the dam was built. On July 14, Lake Powell reached 3,708.34 feet (1,130.30 m) elevation,
19454-460: Was feared that a connection would be made to the bottom of Lake Powell, compromising the dam's foundation and causing the dam to fail. Meanwhile, snow continued melting in the Rockies and Lake Powell continued to rise rapidly. To delay having to use the spillways, the USBR installed plywood flashboards (later replaced by steel) atop the gates to increase the lake level. Even this additional capacity
19596-402: Was filling with sediment at a rate that would render it useless in a few hundred years. But most importantly, Hoover only controlled the lower portion of the river. The Upper Basin states, whose rivers remained undammed, had no way to ensure they could fulfill their delivery obligation to the Lower Basin states while retaining enough water for their own use. Without storage reservoirs of their own,
19738-408: Was generated on September 4, 1964, with the power sent into the regional electric grid through a pair of long-distance transmission lines as far as Phoenix, Arizona and Farmington, New Mexico . It took two more years to complete all remaining aspects of the project. On September 22, 1966 Lady Bird Johnson gave the official dedication speech for Glen Canyon Dam, before a crowd of 3,000 people. With
19880-590: Was intended to provide students in the valley the opportunity to stay within the area while being able to acquire a bachelor's degree for an affordable price without having to transfer to a distant four-year university. The program hosted its first cohorts in the Fall of 2012 and since then has offered various academic programs such as Criminal Justice, History, Liberal Studies, Psychology, Public Administration, and Spanish. Imperial Valley University Program, respectably known as IVUP, has not only offered affordable education and
20022-473: Was lost with the cancellation of the dam project. The Sierra Club lost its IRS tax-exempt status a day after the advertisement was released due to its disruptive political activities. The group's membership more than doubled in the next three years, many of them citizens unhappy with the IRS's apparent overreach. As early as 1947, the Bureau of Reclamation had begun investigating two potential sites, both located in
20164-557: Was most vocally supported by the state of Arizona, which wished to get Colorado River water to Phoenix and Tucson , located hundreds of miles away from the Colorado in the center of the state. Glen Canyon Dam would regulate river flow between Lee's Ferry and Lake Mead, where the Colorado drops some 1,200 feet (370 m), allowing the future construction of two additional hydroelectric dams, at Marble Canyon and Bridge Canyon . These two dams would be partially inside Grand Canyon National Park . Glen, Marble and Bridge together would provide
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