The track was flooded, as well as newly rennovated ($136 million)Pauley Pavilion, the home of UCLA basketball named in honor of the famous coach of winning teams back in the 1970's. At its peak, the broken pipes were sending 35,000 gallons of water per minute onto the streets, with estimates of 20 million gallons released before the flood was brought under control. Maybe the tartan track will survive, the basketball court is questionable. Firefighters had to rescue some people trapped in a parking structure
|Flooded track and athletic field at UCLA|
If you watch the video, you'll see that the jet is strongly pulsating. This is likely due to an effect known as a "water hammer." The pipeline was a high pressure line, and these lines are subject to very destructive forces due to the water hammer effect (sometimes called a hydraulic shock). These are pressure surges that arise when the water changes direction or momentum. In the news, you'll see reports that the pipeline had to be shut down gradually--that's because they had to minimize the potential for water hammers. If a pipe is shut off suddenly at the downstream end (where the vent is on Sunset Boulevard), the mass of water upstream is still moving and therefore can build up high pressure. Such shocks can cause further breakage in the pipelines. (This is common in noisy old water/steam heaters in buildings.)
|Photo of Pauley Pavillion |
basketball court by Jason McIntyre
See the Wiki article for more on water hammers.