Water Well Journal
Issue link: http://read.dmtmag.com/i/592194
The Facts As previously indicated, I have toured Hoover Dam twice. I was privi- leged each time to see design features I had not known before. I want to close this article by highlighting a few of these facts and refuting a few other myths. • Dam Statistics: The dam has a total height of 726.4 feet, the highest dam at the time; the maximum storage depth of water is 590 feet; the crest length (distance across the top of the dam) is 1282 feet; and the maximum compressive pressure at the contact base is 550 psi (79,200 pounds per square foot or 39.6 tons per square foot). There is enough concrete in Hoover Dam to build a two-lane highway from New York to San Francisco. The spillway capacity through two 50-foot-diameter pipes is more than 400,000 cubic feet per second, well above any recorded flow in the Colorado River and suffi- cient to prevent water overtopping the dam. The reservoir (Lake Mead) is the largest man-made lake in America and stores 32,000,000 acre-feet of water at full capacity, well over the originally planned 26,000,000 acre- feet. • Power Plant Statistics: The ultimate original turbine design is 122,300 hp each or a total of 1,835,000 hp (1,323,500 kVA) from the 15 turbine/generating units. The normal operating head range is 420 feet min- imum to 590 feet maximum with an average of 510 to 530 feet. The tur- bine type is a Francis turbine, the design speed is 180 RPM, and each generating unit was originally rated for 82,500 kVA at 16,500 volts AC, 60 Hz. Since the original installation, each of the 15 units has been up- graded to reflect the changes in turbine and generator efficiencies oc- curring through the years and now ENGINEERING from page 61 62 November 2015 WWJ waterwelljournal.com Hoover Dam and appurtenent works general layout.