Coolidge Dam
Encyclopedia
The Coolidge Dam is a reinforced concrete
Reinforced concrete
Reinforced concrete is concrete in which reinforcement bars , reinforcement grids, plates or fibers have been incorporated to strengthen the concrete in tension. It was invented by French gardener Joseph Monier in 1849 and patented in 1867. The term Ferro Concrete refers only to concrete that is...

 multiple dome and buttress dam
Buttress dam
A buttress dam or hollow dam is a dam with a solid, water-tight upstream side that is supported at intervals on the downstream side by a series of buttresses or supports. The dam wall may be flat or curved. Most buttress dams are made of reinforced concrete and are heavy, pushing the dam into the...

 31 miles (49.9 km) southeast of Globe, Arizona
Globe, Arizona
Globe has an arid climate, characterized by hot summers and moderate to warm winters. Globe's arid climate is somewhat tempered by its elevation, however, leading to slightly cooler temperatures and slightly more precipitation than Phoenix or Yuma....

 on the Gila River
Gila River
The Gila River is a tributary of the Colorado River, 650 miles long, in the southwestern states of New Mexico and Arizona.-Description:...

. Built between 1924 and 1928, the Coolidge Dam was part of the San Carlos Irrigation Project. Coolidge Dam was named after the 30th US President, Calvin Coolidge
Calvin Coolidge
John Calvin Coolidge, Jr. was the 30th President of the United States . A Republican lawyer from Vermont, Coolidge worked his way up the ladder of Massachusetts state politics, eventually becoming governor of that state...

 and was dedicated by President Coolidge on March 4, 1930. The design and construction engineer was Herman Neuffer, who oversaw much of the construction undertaken by the Bureau during the 1920s in Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

 and New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

.

Coolidge Dam impounds San Carlos Lake
San Carlos Lake
San Carlos Lake was formed by the construction of the Coolidge Dam and is rimmed by of shoreline. The lake is located within the San Carlos Apache Indian Reservation, and is thus subject to tribal regulations....

 in the San Carlos Apache Indian Reservation
San Carlos Apache Indian Reservation
The San Carlos Apache Indian Reservation, in southeastern Arizona, United States, was established in 1871 as a reservation for the Chiricahua Apache tribe. It was referred to by some as "Hell's Forty Acres," due to a myriad of dismal health and environmental conditions.-Formation:President U.S....

. The project irrigates 100,000 acres (400 km²).

Since the water is impounded so it can be released when farmers need it, San Carlos Lake is often at a low level except in wet periods. When former President Coolidge dedicated the dam in 1930, the dam had not begun to fill. Cherokee
Cherokee
The Cherokee are a Native American people historically settled in the Southeastern United States . Linguistically, they are part of the Iroquoian language family...

 humorist Will Rogers
Will Rogers
William "Will" Penn Adair Rogers was an American cowboy, comedian, humorist, social commentator, vaudeville performer, film actor, and one of the world's best-known celebrities in the 1920s and 1930s....

 looked at the grass in the lake bed, and said, “If this were my dam, I’d mow it.”

Construction

Coolidge Dam was constructed by the Bureau of Indian Affairs
Bureau of Indian Affairs
The Bureau of Indian Affairs is an agency of the federal government of the United States within the US Department of the Interior. It is responsible for the administration and management of of land held in trust by the United States for Native Americans in the United States, Native American...

 (BIA), which also owns and operates it, at a cost of US$10 million. It was built between 1924 and 1928. The overall structure used 200000 cubic yards (152,911 m³) of concrete and consists of three domes, which are supported by massive buttresses on 100 feet (30.5 m) centers. It rises 249 feet (75.9 m), with a crest length of 580 feet (176.8 m). Two uncontrolled ogee crest spillways are concrete lined and located on each abutment
Abutment
An abutment is, generally, the point where two structures or objects meet. This word comes from the verb abut, which means adjoin or having common boundary. An abutment is an engineering term that describes a structure located at the ends of a bridge, where the bridge slab adjoins the approaching...

.

Opposition from Apache tribe

Construction of the dam incurred opposition from the Apache
Apache
Apache is the collective term for several culturally related groups of Native Americans in the United States originally from the Southwest United States. These indigenous peoples of North America speak a Southern Athabaskan language, which is related linguistically to the languages of Athabaskan...

 tribe, who feared a violation of their treaty rights, according to an author writing for the Federal Writers' Project
Federal Writers' Project
The Federal Writers' Project was a United States federal government project to fund written work and support writers during the Great Depression. It was part of the Works Progress Administration, a New Deal program...

:
A compromise was finally made with the Indians, and the tribal burial grounds and the old camp from which Geronimo
Geronimo
Geronimo was a prominent Native American leader of the Chiricahua Apache who fought against Mexico and the United States for their expansion into Apache tribal lands for several decades during the Apache Wars. Allegedly, "Geronimo" was the name given to him during a Mexican incident...

 started his bloody raids now lie deep under the waters of the reservoir
Reservoir
A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...

. It was proposed to disinter the bodies but the Apache vehemently objected to what they considered desecration
Desecration
Desecration is the act of depriving something of its sacred character, or the disrespectful or contemptuous treatment of that which is held to be sacred or holy by a group or individual.-Detail:...

 of the dead, so a concrete slab was laid over the principal burial ground at a cost of $11,000.

Hydroelectric power generation

As part of the San Carlos Indian Irrigation Project (SCIIP), Coolidge Dam generates electricity from a hydroelectric plant. A diesel electric generating plant also run by the Project was built simultaneously and located on reservation land near the town of Coolidge. Both facilities provide power for irrigation
Irrigation
Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...

 wells
Wells
Wells is a cathedral city and civil parish in the Mendip district of Somerset, England, on the southern edge of the Mendip Hills. Although the population recorded in the 2001 census is 10,406, it has had city status since 1205...

, local towns, rural users and mining operations. The electric plant at the dam was completed and began generating electricity in 1935, and the diesel plant was completed in December of that year and produced electricity the following year.

Structural modifications

In 1988, the Bureau of Reclamation completed a study that concluded that the dam needed modifications to prevent a failure should a significant flood or an earthquake occur. Earlier floods that had resulted in water topping the dam had eroded the abutments, and the buttresses were judged to be unstable. Work started in 1991 and included an access road to the downstream side of the dam. The work concluded in 1995. The final cost was estimated at $US46.5 million.

Flood of 1993

In January of 1993, heavy rainfall (up to three times the normal amount) in Arizona filled San Carlos Lake and the operators were forced to release excess water. The ground was saturated, and the continuing rainfall ran off into the streams and rivers. In addition, the weather pattern for the year caused higher than normal temperatures in areas that would typically remain under snow. These areas received rain instead of snow, and the rivers began to run earlier and with far more volume than normal. Rivers in the southern part of Arizona at that time contained anywhere from three to nearly six times their normal amount of water. To complicate matters, the snowpack was already 150% the normal amount. Dam operators for Coolidge Dam released water in record levels because storage capacity had been reached.

As a result of the heavy water releases, several El Paso Natural Gas pipelines, which crossed the Gila River near Coolidge
Coolidge, Arizona
Coolidge is a city in Pinal County, Arizona, United States. According to 2005 Census Bureau estimates, the population of the city is 8,154.Arizona Highway 87 and Arizona Highway 287 pass through the town. Coolidge is 56 miles southeast of Phoenix, and 69 miles northwest of Tucson. It is 21 miles...

, Winkleman, and Kelvin were “scoured” or uncovered by the force of the water and failed. The water flow was concentrated through the release gates, as opposed to letting the water overtop the dam, which would have created a different scour rate. The force of the Gila River undermined and ultimately caused the failure of the north and south abutments of the bridge crossing at Attaway Road, upstream from Coolidge. The estimated flow from Coolidge Dam during January of 1993 was 927 cubic meters per second, about seven times the expected maximum release rate, 133 cubic meters per second, and was the highest release rate for the dam since its construction. Discharge at Winkleman was recorded at 1050 cubic meters per second on January 20, 1993. Winkleman Flats, a small area near Winkleman, was flooded as well. However, despite earlier concerns about the dam's safety, it survived the flood even though retrofit work was in process at the time.

Recreational use

Fishing and boating

San Carlos Lake is stocked periodically, and when the winter has experienced average or above average precipitation, is one of the largest lakes in Arizona. The San Carlos Apache Tribe Recreation & Wildlife Dept. stocks several species of fish using various methods to create a good fishing environment. Several species are self-sustaining:
  • sunfish
    Lepomis
    Lepomis is a genus of freshwater fish in the sunfish family of order Perciformes. The most recognizable species of the sixteen in this genus is the Bluegill....

     (Lepomis sp.)
  • largemouth bass
    Largemouth bass
    The largemouth bass is a species of black bass in the sunfish family native to North America . It is also known as widemouth bass, bigmouth, black bass, bucketmouth, Potter's fish, Florida bass, Florida largemouth, green bass, green trout, linesides, Oswego bass, southern largemouth...

     (Micropterus salmoides)
  • black crappie
    Crappie
    Crappie is a genus of freshwater fish in the sunfish family of order Perciformes. The type species is P. annularis, the white crappie...

     (Pomoxis nigromaculatus)
  • channel catfish
    Catfish
    Catfishes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...

     (Ictalurus punctatus)
  • flathead catfish (Pylodictis olivaris)


Other fish are stocked from cold-water fisheries including brown trout
Brown trout
The brown trout and the sea trout are fish of the same species....

 and rainbow trout
Rainbow trout
The rainbow trout is a species of salmonid native to tributaries of the Pacific Ocean in Asia and North America. The steelhead is a sea run rainbow trout usually returning to freshwater to spawn after 2 to 3 years at sea. In other words, rainbow trout and steelhead trout are the same species....

. Jet-skiing, water skiing and boating are allowed. Individuals who are not members of the San Carlos Apache tribe who wish to use the lake must contact the tribal office for a permit since the lake is on tribal land.

Bicycle trail

Bicyclists can ride the access road to the dam face and back. The route is scenic and little-traveled, and rises a total of about 700 feet along the 13 mile route. The elevation
Elevation
The elevation of a geographic location is its height above a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface ....

 at the dam is about the same as the starting point, so the trip is not strictly a climb, but peaks about the middle of the distance and then descends again to about 2,600 ft.

When they reach the dam, cyclists can either return to the starting point along the two-lane paved road, or they can continue eastward along the rougher part of the road until it rejoins US Route 70. Before traveling on the reservation, non-tribe members must obtain a permit. A mountain bike
Mountain bike
A mountain bike or mountain bicycle is a bicycle created for off-road cycling. This activity includes traversing of rocks and washouts, and steep declines,...

 or other rugged type bicycle is recommended for cyclists traveling east from the dam to Rte 70.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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