by Jay Lund
“In February, 1914, the rainfall in the Mojave Desert region exceeded by nearly fifty per cent in three days the average annual precipitation.
Where the steel siphon crosses Antelope valley at the point of greatest depression, an arroyo or run-off wash indicated that fifteen feet was the extreme width of the flood stream, and the pipe was carried over the wash on concrete piers set just outside the high water lines. The February rain, however, was of the sort known as a cloud-burst, and the flood widened the wash to fifty feet, carried away the concrete piers, and the pipe sagged and broke at a circular seam. The water in the pipe escaped rapidly through the break under a head of 200 feet, and the steel pipe collapsed like an emptied fire hose for nearly two miles of its length. In some places the top of the pipe was forced in by atmospheric pressure to within a few inches of the bottom. The pipe is ten feet in diameter, and the plates are 1/4 and 5/16 of an inch thick. Many engineers pronounced the collapsed pipe a total loss, and advised that it be taken apart, the plates re-rolled and the siphon rebuilt.
The damage was repaired, however, by the simple expedient of turning the water on after the break was mended, relying on the pressure to restore the pipe to circular form. The hydraulic pressure, under gradually increasing head, restored the pipe to its original shape without breaking any of the joints or shearing the rivets, and a month after the collapse the siphon was as good as new. The total cost of repairing the siphon was only $3,000. It would have cost about $250,000 to take it apart and rebuild it” (LABPSC 1916).
Water management and policy has always faced challenges, even unexpected ones following great technical triumphs. California’s water problems have never been easy.
But sometimes challenges require only creative solutions based on fundamental insights and a willingness, occasionally driven by desperation, to venture forth and adapt.
Jay Lund is the Director of the Center for Watershed Sciences and Professor of Civil and Environmental Engineering at the University of California – Davis. This is a re-posting from May 2016.
Complete report on construction of the Los Angeles aqueduct, Los Angeles Board of Public Service Commissioners, Los Angeles, CA 1916. (pp. 20-21)
Water and Power Associates. Construction of the Los Angeles Aqueduct
Very cool. Suspecting I join the overwhelming majority who had no idea there was ever a riveted siphon vacuuming water from Mojave to LA. Can you imagine in the current environment anyone even conceiving such a scheme?
Well, they dreamed of it, foolishly thinking we have any real understanding of the Nino. Thinking that we are in touch with the clockwork and could predict a rerun of 1983.
Evidently not. Not the climatic Nino, but a cloudburst, a localized “weather” phenomenon busted the rivets in 1914, the first year of the First World War.
Here’s to ingenuity. We’re going to need all we can get. We are going to need to bust all the rivets of foolish preconceptions, roll up our sleeves, and get to work.
Cool Pictures and engineering. How about an article regarding adding fish Screens to the Delta Water pumps that would actually prevent all KILLING of Delta life including Endangered species? It is almost 1 mile from the Clifton Fore bay to the SWP pumps but water officials only consider putting the screens the 800 feet across the canal instead of along the entire length of the canal. If not Fish Screens how about ultra Filtration like ZeeWeed or Puron.
Pingback: MAVEN'S NOTEBOOK - Water news
Pingback: Human Ingenuity At Work! | Parkway Blog
Technically all of the ‘siphons’ on the Los Angeles Aqueduct are inverted siphons or as LADWP calls them ‘Sag Pipes’. There is no vacuum required to pull water through the pressure pipe like a regular siphon. The elevation is higher where the water enters the sap pipes than where it exits downstream. The aqueduct also does not require pumps to move the water. It’s literally all down hill from Mono Lake to the Van Norman Reservoir.