120mw Parker Dam creates Lake Havasu

(Satellite, 150 photos)

I learned of Lake Havasu when I researched the London Bridge.

usbr
"Parker Dam is a concrete arch structure commonly called the 'deepest dam in the world'.  Seventy-three percent of the dam's structural height of 320 feet [98m] is below the original river bed; only about 85 feet [26m] of the dam's structural height is visible (its superstructure rises another 62 feet [19m] above the roadway across the top of the dam). Parker Dam has a volume of 380,000 cubic yards of concrete. At its crest, the dam is 856 feet [261m] long. Water control is provided by five 50-ft [50m]-square gates." The capacity of the powerplant is 120mw.

usbr
"Lake Havasu backs up behind the dam for 45 miles and covers more than 20,400 acres (32 square miles). The reservoir's total capacity is 646,200 acre-feet. The Metropolitan Water District`s W. P. Whitsett Intake Pumping Plant for the Colorado River Aqueduct is located on the shore of Lake Havasu about two miles upstream from the dam. The aqueduct begins at the intake pumping plant and extends 242 miles to its terminus at Lake Mathews near Riverside, California. About half of the power generated at Parker Dam is reserved by MWD to pump Colorado River water along the Colorado River Aqueduct."

The Hoover Dam posted

Did you know Parker Dam is the deepest dam in the world? About 73 percent of its 320-foot height is hidden underwater. This engineering marvel creates Lake Havasu along the Arizona and California border, transforming the desert into a beautiful oasis.

Inside the Parker Dam Powerplant, four massive penstocks, each 22 feet in diameter, carry more than 41,000 gallons of water per second [5,481cfs] to spin generators and produce clean energy. With a nameplate capacity of 120,000 kilowatts, this powerhouse helps the Bureau of Reclamation remain the second largest producer of hydropower in the United States.

Bureau of Reclamation posted
In July of 1937, the first bucket of concrete was placed in Parker Dam, 245 feet [75m] below the level of #ColoradoRiver. One year later, the last bucket of concrete was placed, and Lake Havasu began to fill in October of 1938. 

nps

Underestimated Arsenal posted

"The deepest foundation ever excavated for a dam," W. I. Swanton, a Bureau of Reclamation engineer, wrote in January 1938 of Parker Dam, on the Colorado River between Arizona and California.

Of the dam's structural height of 320 feet [97.5m], 73 percent lies below the original bed of the river, the Bureau says today. Its builders excavated 235 feet [71.6m] into the riverbed before concrete was placed for the foundation. About 85 feet [26m] of the dam is visible, and the superstructure on top rises another 62 feet [19m] above the roadway across it.

They dug that deep for rock. Engineers digging for bedrock on which to build had to go so far down, the National Park Service says, that most of the dam is out of sight.

Bureau of Reclamation engineers designed the dam. The J. F. Shea company, one of the Six Companies that had built Hoover Dam, built it, and Ernest A. Moritz was the Bureau's construction engineer in charge.

Nothing could be dug while the Colorado ran over the site, so the river was sent around it. Two diversion tunnels, each 29 feet [8.8m] across and 1,730 feet [527m] long, were holed through by the end of April 1936. By the end of May, when work stopped for the hot weather, both had been lined with concrete. The pit was dug behind two temporary cofferdams, walls that held the river back and turned it into the tunnels. The cofferdams alone were an investment of more than $2,000,000.

A photograph the Bureau published in April 1937 shows the pit at work: a dragline, a machine that drags a bucket across the ground, loading a skip, the bucket that rides a cableway. The cableway ran on two movable towers and one fixed tower.

The first bucket of concrete went into the dam on 29 July 1937.

At the end of that year the Bureau listed the dam 90 percent complete, with nearly a thousand men at work. By mid-June 1938 the cofferdams were out, and on 1 July the Colorado returned to its bed. The last load of concrete went into the dam on 26 July, almost a year after the first, and the dam was substantially completed that September.

Parker Dam stands 17 miles northeast of the town of Parker, Arizona, and the Bureau still calls it the deepest dam in the world. Visitors can park in the turnout on the California side and look over it. Behind it, Lake Havasu runs about 45 miles.

What they see is the top. The other 235 feet are still where the crews left them, in the riverbed.

Each gate in this photograph is 50 feet [15.2m] square and weighs over 400,000 pounds, The Reclamation Era said in January 1939. Parker Dam has five, and water is passing through two of them here.

The Bureau engineer who took over the task of installing those gates was Howard P. Bunger, moved to Parker from Marshall Ford Dam in Texas to bring the dam to completion, the magazine reported in January 1938. He was born at Wheat Ridge, Colorado, took his engineering degree at the University of Colorado in 1914, served with the Santa Fe Railroad and spent years on engineering and reclamation work in Mexico. The engineer he replaced, Ernest A. Moritz, was born in Sheboygan, Wisconsin. He had worked on railroads, then for the Bureau on its Yakima project in Washington, its Flathead project in Montana and in its offices in Washington, D.C., and Denver. He went on to Marshall Ford Dam, where concrete had just started to be poured. The Bureau wrote that most of Parker's concrete work was finished under his direction.

About the photograph: it is held by the National Archives in the Army Air Forces series "Airscapes" of American and Foreign Areas, local identifier 18-AA-12-15, titled "Arizona - Parker". The archive names no photographer and gives no date; the series runs from 1917 to 1964. The plate number, 39993 A.C., in white near the bottom edge was cropped off, along with the print's edges, and nothing else was changed. Two other prints in the same folder are lettered 5-24-43, which reads as 24 May 1943, and one of them shows a power plant standing at the left end of the dam. Here that ground is still a work site, so this print is older; the Bureau says the plant was substantially completed in 1942. The photograph also cannot show what the post is about, because the foundation is under the riverbed.

Where the numbers on the photo come from:

Two hundred and thirty five (235) feet: the Bureau's website says men and machines excavated 235 feet into the Colorado riverbed before concrete was placed, and its magazine gave the same figure in January 1938. Trade-magazine articles listed in The Reclamation Era gave other figures while the pit was still going down: a February 1937 headline said 250 feet, an August 1937 note said bedrock was reached at 240. The post uses the Bureau's 235.

Most of this dam: the Bureau says 73 percent of its structural height of 320 feet is below the original riverbed. That is about 235 feet of the 320.

Two tunnels: the April 1937 Reclamation Era says the Colorado was diverted through two tunnels, each 29 feet in diameter and 1,730 feet long. The Historic American Engineering Record gives their dates.

Eighty five (85) feet: the Bureau says about 85 feet of the dam are visible; its superstructure rises another 62 feet above the roadway across the top.

Forty five (45) miles: the Bureau gives Lake Havasu as about 45 miles long.

"Deepest dam in the world" is the Bureau's description, and the Library of Congress record says it is "commonly called" that. The post quotes the 1938 phrase, "the deepest foundation ever excavated for a dam", as the Bureau's engineer wrote it.

The dam is still a Bureau of Reclamation dam; the Western Area Power Administration markets power from its plant.

Joe Swaim commented on the above post
All 5 open at once. Flood - 1983

Don Barrett Flickr, License: Creative Commons Attribution-NonCommercial-ShareAlike (CC BY-NC-SA)

LivingNewDeal
This dam is considered a diversion dam. "The diversion of the water from the Colorado River is made by the Parker Dam which raises the water level in the river 72 feet [22m] to the first pumping plant. The main aqueduct consists of 91 miles of tunnel, 55 miles of cut and cover conduit, 65 miles of lined canal, and 27 miles of various kinds of reassure pipe, making a total of 238 miles of aqueduct. The total pump lift, after diversion is completed by the Parker Dam, is 1,614 feet [492m]."

Bureau of Reclamation posted two images with the comment: "Together, the four generator units at the Parker Dam Powerplant put out about 428,000 megawatt-hours of energy annually, providing power to Arizona, California, and Nevada. Each component of the hydroelectric generating unit is impressive. The generator shaft shown here weighs an astounding 22 tons and is nearly 24 feet [7.3m] long! It is built to harness the 40,000 horsepower the turbines produce and spin at roughly 95 RPM."

Richard Polivka: Generator is 76 poles - 60 Hz @ 94.74 RPM.

[Some comments discuss some technicalities about the turbine.]

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