Glen Canyon Dam
Glen Canyon Dam is a concrete arch-gravity dam on the Colorado River in northern Arizona, United States, near the town of Page. The 710-foot high dam was built by the U. S. Bureau of Reclamation from 1956 to 1966 and forms Lake Powell, one of the largest man-made reservoirs in the U. S. with a capacity of 27 million acre feet. The dam is named for a series of deep sandstone gorges now flooded by the reservoir. A dam in Glen Canyon was studied as early as 1924, but these plans were dropped in favor of the Hoover Dam, located in 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. However, the USBR faced opposition when it proposed the Echo Park Dam in Utah's Dinosaur National Monument, which the nascent environmental movement saw as a legal threat to the status of protected lands. After a long fight, the USBR agreed not to build the dam in Dinosaur National Monument, but only if the environmentalists did not oppose the proposed dam in Glen Canyon.
Since first filling to capacity in 1980, Lake Powell water levels have fluctuated depending on water demand and annual runoff. Operation of Glen Canyon Dam helps ensure an equitable distribution of water between the states of the Upper Colorado River Basin and the Lower Basin. 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 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 and water-skiing, attracts millions of tourists each year to 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 the ecology of the Grand Canyon, which lies downstream. Water managers and utilities state that the dam is a major source of renewable energy and provides a vital defense against severe droughts; the Colorado River is the single largest source of water in the southwestern United States and northwest Mexico. Annual discharge from the Colorado River and its tributaries ranges from 4 to 22 million acre feet, 10-year averages may fluctuate as much as 1 million acre feet. Flooding, the river's enormous silt or sediment load, created problems for settlements in the Lower Colorado River Valley and navigation on 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 and Arizona began to call for a dam to control the tempestuous river.
In 1922, six U. S. states signed the Colorado River Compact to allocate the flow of the Colorado River and its tributaries. Each half of the Colorado River Basin – the Upper Basin, comprising Colorado, New Mexico and Wyoming – and the Lower Basin, with California and Nevada – was allotted 7.5 million acre feet of water annually, a treaty between the U. S. and Mexico was signed in 1944 allocating 1.5 million acre feet to Mexico. The third lower basin state, 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, was based on only thirty years of streamflow records starting in the late 1890s. It was believed to represent the annual flow as measured at Lee's Ferry, Arizona, 16 miles 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.
The general consensus among inhabitants of 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, in fact 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 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. However, what killed the first Glen Canyon proposal was the fact that it lies upstream of the Lee's Ferry dividing line, thus would be considered the Upper Basin's water. With its substantial Congressional clout, Cal
Hoover Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the U. S. states of Nevada and Arizona. It was constructed between 1931 and 1936 during the Great Depression and was dedicated on September 30, 1935, by President Franklin D. Roosevelt, its construction was the result of a massive effort involving thousands of workers, cost over one hundred lives. Known as Boulder Dam from 1933, it was renamed Hoover Dam, for President Herbert Hoover, by a joint resolution of Congress in 1947. Since about 1900, the Black Canyon and nearby Boulder Canyon had been investigated for their potential to support a dam that would control floods, provide irrigation water and produce hydroelectric power. In 1928, Congress authorized the project; the winning bid to build the dam was submitted by a consortium called Six Companies, Inc. which began construction on the dam in early 1931. Such a large concrete structure had never been built before, some of the techniques were unproven.
The torrid summer weather and lack of facilities near the site presented difficulties. Six Companies turned the dam over to the federal government on March 1, 1936, more than two years ahead of schedule. Hoover Dam impounds the largest reservoir in the United States by volume; the dam is located near Boulder City, Nevada, a municipality constructed for workers on the construction project, about 30 mi southeast of Las Vegas, Nevada. The dam's generators provide power for public and private utilities in Nevada and California. Hoover Dam is a major tourist attraction; the traveled U. S. Route 93 ran along the dam's crest until October 2010; as the United States developed the Southwest, the Colorado River was seen as a potential source of irrigation water. An initial attempt at diverting the river for irrigation purposes occurred in the late 1890s, when land speculator William Beatty built the Alamo Canal just north of the Mexican border. Though water from the Imperial Canal allowed for the widespread settlement of the valley, the canal proved expensive to maintain.
After a catastrophic breach that caused the Colorado River to fill the Salton Sea, the Southern Pacific Railroad spent $3 million in 1906–07 to stabilize the waterway, an amount it hoped in vain would be reimbursed by the Federal Government. After the waterway was stabilized, it proved unsatisfactory because of constant disputes with landowners on the Mexican side of the border; as the technology of electric power transmission improved, the Lower Colorado was considered for its hydroelectric-power potential. In 1902, the Edison Electric Company of Los Angeles surveyed the river in the hope of building a 40-foot rock dam which could generate 10,000 horsepower. However, at the time, the limit of transmission of electric power was 80 miles, there were few customers within that limit. Edison allowed land options it held on the river to lapse—including an option for what became the site of Hoover Dam. In the following years, the Bureau of Reclamation, known as the Reclamation Service at the time considered the Lower Colorado as the site for a dam.
Service chief Arthur Powell Davis proposed using dynamite to collapse the walls of Boulder Canyon, 20 miles north of the eventual dam site, into the river. The river would carry off the smaller pieces of debris, a dam would be built incorporating the remaining rubble. In 1922, after considering it for several years, the Reclamation Service rejected the proposal, citing doubts about the unproven technique and questions as to whether it would in fact save money. In 1922, the Reclamation Service presented a report calling for the development of a dam on the Colorado River for flood control and electric power generation; the report was principally authored by Davis, was called the Fall-Davis report after Interior Secretary Albert Fall. The Fall-Davis report cited use of the Colorado River as a federal concern because the river's basin covered several states, the river entered Mexico. Though the Fall-Davis report called for a dam "at or near Boulder Canyon", the Reclamation Service found that canyon unsuitable.
One potential site at Boulder Canyon was bisected by a geologic fault. The Service found it ideal. Despite the site change, the dam project was referred to as the "Boulder Canyon Project". With little guidance on water allocation from the Supreme Court, proponents of the dam feared endless litigation. A Colorado attorney proposed that the seven states which fell within the river's basin form an interstate compact, with the approval of Congress; such compacts were authorized by Article I of the United States Constitution but had never been concluded among more than two states. In 1922, representatives of seven states met with then-Secretary of Commerce Herbert Hoover. Initial talks produced no result, but when the Supreme Court handed down the Wyoming v. Colorado decision undermining the claims of the upstream states, they became anxious to reach an agreement; the resulting Colorado River Compact was signed on November 24, 1922. Legislation to authorize the dam was introduced by two California Republicans, Representative Phi
A tributary or affluent is a stream or river that flows into a larger stream or main stem river or a lake. A tributary does not flow directly into a ocean. Tributaries and the main stem river drain the surrounding drainage basin of its surface water and groundwater, leading the water out into an ocean. A confluence, where two or more bodies of water meet together refers to the joining of tributaries; the opposite to a tributary is a distributary, a river or stream that branches off from and flows away from the main stream. Distributaries are most found in river deltas. "Right tributary" and "left tributary" are terms stating the orientation of the tributary relative to the flow of the main stem river. These terms are defined from the perspective of looking downstream. In the United States, where tributaries sometimes have the same name as the river into which they feed, they are called forks; these are designated by compass direction. For example, the American River receives flow from its North and South forks.
The Chicago River's North Branch has the East and Middle Fork. Forks are sometimes left. Here, the "handedness" is from the point of view of an observer facing upstream. For instance, Steer Creek has a left tributary, called Right Fork Steer Creek. Tributaries are sometimes listed starting with those nearest to the source of the river and ending with those nearest to the mouth of the river; the Strahler Stream Order examines the arrangement of tributaries in a hierarchy of first, second and higher orders, with the first-order tributary being the least in size. For example, a second-order tributary would be the result of two or more first-order tributaries combining to form the second-order tributary. Another method is to list tributaries from mouth to source, in the form of a tree structure, stored as a tree data structure. A gallery of major river basins with tributaries Estuary
Green River (Colorado River tributary)
The Green River, located in the western United States, is the chief tributary of the Colorado River. The watershed of the river, known as the Green River Basin, covers parts of Wyoming and Colorado; the Green River is 730 miles long, beginning in the Wind River Mountains of Wyoming and flowing through Wyoming and Utah for most of its course, except for 40 miles into western Colorado. Much of the route is through the Colorado Plateau and through some of the most spectacular canyons in the United States, it is only smaller than the Colorado when the two rivers merge, but carries a larger load of silt. The average yearly mean flow of the river at Green River, Utah is 6,121 cubic feet per second; the status of the Green River as a tributary of the Colorado River came about for political reasons. In earlier nomenclature, the Colorado River began at its confluence with the Green River. Above the confluence the Colorado was called the Grand River. In 1921, Colorado U. S. Representative Edward T. Taylor petitioned the Congressional Committee on Interstate and Foreign Commerce to rename the Grand River as the Colorado River.
On July 25, 1921, the name change was made official in House Joint Resolution 460 of the 66th Congress, over the objections of representatives from Wyoming and Utah and the United States Geological Survey which noted that the drainage basin of the Green River was more extensive than that of the Grand River, although the Grand carried a higher volume of water at its confluence with the Green. It rises in western Wyoming, in northern Sublette County, on the western side of the Continental Divide in the Bridger-Teton National Forest in the Wind River Range, it flows south through Sublette County and western Wyoming in an area known as the Upper Green River Valley southwest and is joined by the Big Sandy River in western Sweetwater County. At the town of La Barge, it flows into Fontenelle Reservoir, formed by Fontenelle Dam. Below there, it flows through open sage covered rolling prairie where it is crossed by the Oregon and Mormon emigration trails and further south until it flows past the town of Green River and into the Flaming Gorge Reservoir in Southwestern Wyoming, formed by the Flaming Gorge Dam in northeastern Utah.
Prior to the creation of the reservoir, the Blacks Fork joined the Green River south of Green River, today the mouth of Blacks Fork is submerged by the reservoir. South of the dam it flows eastward, looping around the eastern tip of the Uinta Mountains going from Utah into northwestern Colorado and through Browns Park before turning west and south into Dinosaur National Monument where it passes through the Canyon of the Lodore and is joined by the Yampa River at Steamboat Rock, it turns westward back into Utah along the southern edge of the Uintas in Whirlpool Canyon. In Utah it meanders southwest across the Yampa Plateau and through the Uintah and Ouray Indian Reservation and the Ouray National Wildlife Refuge. Two miles south of Ouray, Utah, it is joined by Duchesne River, three miles downstream by the White River. Ten miles farther downstream it is joined by the Willow River. South of the plateau, it is joined by Nine Mile Creek enters the Roan Cliffs where it flows south through the back-to-back Desolation and Gray canyons, with a combined length of 120 mi.
In Gray Canyon, it is joined by the Price River. South of the canyon it passes the town of Green River, Utah and is joined by the San Rafael River in southern Emery County. In eastern Wayne County it meanders through Canyonlands National Park; the Flaming Gorge Dam in Utah is a significant regional source of water for irrigation and mining, as well as for hydroelectric power. Begun in the 1950s and finished in 1963, it was controversial and opposed by conservationists. A dam was to be built in Whirlpool Canyon, but the conservationist movement traded the Flaming Gorge dam for halting that proposal. Apocryphally, the Sierra Club, a not-for-profit environmental organization, lost its tax-exempt status for political action in opposing the proposed dam; the Green is a large, powerful river. It ranges from 100 to 300 feet wide in the upper course to 300 to 1,500 feet wide in its lower course and ranges from 3 to 50 feet in depth, it is navigable by small craft throughout its course and by large motorboats upstream to Flaming Gorge Dam.
Near the areas where the Oregon Trail crosses, the river is 400 - 500 feet wide and averages about 20 feet deep at normal flow. Archaeological evidence indicates that the tributary canyons and sheltered areas in the river valley were home to the Fremont Culture, which flourished from the 7th century to the 13th century; the Fremont were a semi-nomadic people who lived in pithouses and are best known for the rock art on canyon walls and in sheltered overhangs. In centuries, the river basin was home to the Shoshone and Ute peoples, both nomadic hunters; the Shoshone inhabited the river valley north of the Uinta Mountains, whereas the Utes lived to the south. The current reservation of the Utes is in the Uintah Basin; the Shoshone called the river the Seeds-kee-dee-Agie, meaning "Prairie Hen River." In 1776, the Spanish friars Silvestre Vélez de Escalante and Francisco Atanasio Domínguez crossed the river near present-day Jensen, naming it the Rio de San Buenaventura. The map-maker of the expedition, Captain Bernardo Miera y Pacheco, erroneously indicated that the river flowed southwest to what is now known as Sevier Lake.
Cartographers extended the error, representing the Buenaventura River as flowing into the Pacific Ocean. At least one charted the Buenaventura as draining the Great Salt Lake. Spanish
The Virgin River is a tributary of the Colorado River in the U. S. states of Utah and Arizona. The river is about 162 miles long, it was designated Utah's first wild and scenic river in 2009, during the centennial celebration of Zion National Park. The river is named for Thomas Virgin, a member of the first American party to see it, led by Jedediah Smith in 1826. Smith named it "Adams River", after then-president John Quincy Adams, but explorer and mapmaker John C. Fremont gave it its current name. After the Smith party descended the river on the way to California, Thomas Virgin was badly wounded in an attack by Mohave people during the crossing of the Mojave Desert. Virgin recovered from his wounds but was killed, along with most of Smith's companions, in an attack by Umpqua people; the Old Spanish Trail followed the Virgin River for part of its length from near St. George to the point it ascended the Mormon Plateau to cross to the Muddy River in present-day Nevada, its origin is in Southwestern Utah, at the Navajo Reservoir in the Dixie National Forest, north of Zion National Park, is formed by the confluence of the East Fork Virgin, that flows through Mount Carmel Junction on the east side of Zion National Park and Parunaweap Canyon, with the North Fork Virgin River, that flows from Navajo Lake through Zion Canyon in Zion National Park.
The river flows in a southwesterly direction, passing south of the old townsite of St. George where the Santa Clara River joins the Virgin at a place the Paiutes called Tonaquint; the river flows across the northwestern corner of Arizona through the Virgin River Gorge and past the towns of Beaver Dam and Littlefield. It enters southern Nevada near the town of Mesquite and empties into the Colorado at the Lake Mead reservoir 40 miles east of Las Vegas; the last 30 miles of the Virgin River forms the north arm of Lake Mead. Despite flowing through an arid region, the Virgin River is home to a diverse array of plants and animals. Southwestern Utah is located at the intersection of three physiographic regions: the Colorado Plateau, the Great Basin, the Mojave Desert; the exceptional landscapes and habitats of this region harbor unique plant and animal communities and species found nowhere else in the world. Without the water of the Virgin River system, these species could not exist; the Virgin River directly supports hundreds of wildlife species including, Virgin River chub, Virgin spinedace, flannelmouth sucker, desert sucker, speckled dace, Southwestern Willow Flycatcher.
Many of these species are considered sensitive species within the State of Utah. The Virgin River Program was established to balance increasing human demand and maintain this unique system. Woundfin Federally listed endangered species Size: 4″ One of the rarest species on earth, the endangered woundfin is found only in a small section of the Virgin River. Woundfin have large fins and scale-less, streamlined bodies that help them survive in swift, silty conditions. Although small, it is shark-like in both appearance and action as it feeds on small insects in shallow areas along the river. Woundfin live only one to two years and their survival depends upon sufficient flow within the river during hot summer months. Virgin River chub Federally listed endangered species Size: 18 " Rare and beautiful, this fish is the top native predator in the Virgin River. Chub are a fast streamlined fish with a sloped forehead, humped back, thin rounded tail; the Virgin River chub feeds on small fish and plant matter.
Chub runs with boulders and debris for cover. Virgin River chub were once an important food source for early pioneers. Listed as an endangered species, the Virgin River chub is found from Pah Tempe Hot Springs down to Halfway Wash, Nevada. Desert sucker State of Utah wildlife species of concern Size: 18″ The desert sucker gets its name from the way it feeds on aquatic vegetation and insects, it uses its thick cartilaginous lips to scrape and suck food from rocks and boulders along the bottom of the river. Desert Suckers are colorful during the spring spawning season, developing bright orange and black'racing stripes' along their sides. Desert suckers are considered a sensitive species in Utah, where they are only found in the Virgin River and its tributaries. Speckled dace Size: 4 " One of the most widespread species in western North America, the speckled dace is found in large numbers throughout the Virgin River and its tributaries. Speckled dace are comfortable living in all habitats and stream sizes.
Speckled dace exhibit a kaleidoscope of colors across their range. Males display red fins to attract mates during breeding season. Southwestern Willow Flycatcher Federally listed endangered species The Southwestern Willow Flycatcher occurs in dense riparian habitats along streams rivers, other wetlands. At low elevations, the flycatcher breeds in dense, patchy habitats composed of mid-sized to tall trees and shrubs. At higher elevations, it occurs in dense stands of low to moderate height riparian shrubs. Vegetation density within 4 m is important. Preferred habitats are always associated with standing or slow-flowing water; the destruction of riparian habitats has caused a severe decline in the populations of the southwestern willow flycatcher. This sub-species exists only in fragmented and scattered locations throughout its range; the breeding range reached from southern California, southern Nevada, so
Davis Dam is a dam on the Colorado River about 70 miles downstream from Hoover Dam. It stretches across the border between Nevada. Called Bullhead Dam, Davis Dam was renamed after Arthur Powell Davis, the director of the U. S. Bureau of Reclamation from 1914 to 1923; the United States Bureau of Reclamation owns and operates the dam, completed in 1951. Davis Dam forms Lake Mohave. Davis DamDavis Dam is a zoned earth-fill dam with a concrete spillway, 1,600 ft in length at the crest, 200 ft high; the earth fill dam begins on the Nevada side, but it does not extend to the Arizona side on the east. Instead, there is an inlet formed by concrete, that includes the spillway; the hydroelectric power plant is beside the inlet. The dam's purpose is to re-regulate releases from Hoover Dam upstream, facilitate the delivery of Colorado River water to Mexico. Bullhead City and Laughlin, are located just below the dam along the river. Davis Camp is nearby. Bullhead City was a construction town for workers building the dam.
A road is located on the crest of the earth fill portion of the dam and a Forebay Bridge spans the Forebay. It was part of Arizona State Route 68 to Nevada. In April 2004, the roadway was shut down to vehicle traffic. Pedestrian and bicycle traffic are permitted; the old roadway is now an extension of the Heritage Trail system. Barriers have been placed on the former road at each end of the earthen dam; the facility is patrolled by security forces who enforce parking regulations. Davis Dam Hydroelectric Power PlantThe Davis Dam Power Plant is a hydroelectric power plant located on the Arizona side of the dam, beside the inlet; the hydroelectric plant generates between 2 terawatt-hours of electricity annually. The plant has a capacity of 251 MW and the tops of its five Francis turbines are visible from outside the plant; the plant's head is 136 ft. Dams of the Lower Colorado River Valley Bullhead City, Arizona Laughlin, Nevada List of power stations in the United States USBR - Davis Dam USBR - Davis Power Plant USBR - Parker-Davis Project USGS - Real Time Water Data Historic American Engineering Record No.
AZ-77, "Davis Dam" HAER No. AZ-77-A, "Davis Dam, Switchyards"
Hydraulic head or piezometric head is a specific measurement of liquid pressure above a vertical datum. It is measured as a liquid surface elevation, expressed in units of length, at the entrance of a piezometer. In an aquifer, it can be calculated from the depth to water in a piezometric well, given information of the piezometer's elevation and screen depth. Hydraulic head can be measured in a column of water using a standpipe piezometer by measuring the height of the water surface in the tube relative to a common datum; the hydraulic head can be used to determine a hydraulic gradient between two or more points. In fluid dynamics, head is a concept that relates the energy in an incompressible fluid to the height of an equivalent static column of that fluid. From Bernoulli's Principle, the total energy at a given point in a fluid is the energy associated with the movement of the fluid, plus energy from static pressure in the fluid, plus energy from the height of the fluid relative to an arbitrary datum.
Head is expressed in units of height such as feet. The static head of a pump is the maximum height; the capability of the pump at a certain RPM can be read from its Q-H curve. A common misconception is that the head equals the fluid's energy per unit weight, while, in fact, the term with pressure does not represent any type of energy. Head is useful in specifying centrifugal pumps because their pumping characteristics tend to be independent of the fluid's density. There are four types of head used to calculate the total head in and out of a pump: Velocity head is due to the bulk motion of a fluid, its pressure head correspondent is the dynamic pressure. Elevation head is due to the gravitational force acting on a column of fluid. Pressure head is due to the static pressure, the internal molecular motion of a fluid that exerts a force on its container. Resistance head is due to the frictional forces acting against a fluid's motion by the container. A mass free falling from an elevation z > 0 will reach a speed v = 2 g z, when arriving at elevation z=0, or when we rearrange it as a head: h = v 2 2 g where g is the acceleration due to gravityThe term v 2 2 g is called the velocity head, expressed as a length measurement.
In a flowing fluid, it represents the energy of the fluid due to its bulk motion. The total hydraulic head of a fluid is composed of elevation head; the pressure head is the equivalent gauge pressure of a column of water at the base of the piezometer, the elevation head is the relative potential energy in terms of an elevation. The head equation, a simplified form of the Bernoulli Principle for incompressible fluids, can be expressed as: h = ψ + z where h is the hydraulic head known as the piezometric head. Ψ is the pressure head, in terms of the elevation difference of the water column relative to the piezometer bottom, z is the elevation at the piezometer bottom In an example with a 400 m deep piezometer, with an elevation of 1000 m, a depth to water of 100 m: z = 600 m, ψ = 300 m, h = 900 m. The pressure head can be expressed as: ψ = P γ = P ρ g where P is the gauge pressure, γ is the unit weight of the liquid, ρ is the density of the liquid, g is the gravitational acceleration The pressure head is dependent on the density of water, which can vary depending on both the temperature and chemical composition.
This means that the hydraulic head calculation is dependent on the density of the water within the piezometer. If one or more hydraulic head measurements are to be compared, they need to be standardized to their fresh water head, which can be calculated as: h f w = ψ ρ ρ f w + z where h f w is the fresh water head, ρ f w is the density of fresh water The hydraulic gradient is a vector gradient between two or more hydraulic head measurements over the length of the flow path. For groundwater, it is called the'Darcy slope', since it determines the quantity of a Darcy flux or discharge, it has applications in open-channel flow