What happens when the government imposes forced water conservation on a city with aging water pipes?
You guessed it!
The reduced water demand increases the amount of water in storage tanks and increases the pressure of the water in the water distribution system. And guess what happens then?
Right again!
Right again!
Water pipes are breaking all over the place!!
This past month in Los Angeles alone, there were at least a half dozen water mains that ruptured causing giant sink holes and flooding. These large pipes deliver thousands of gallons of fresh water per minute. It often takes more than an hour to get the water turned off, as well. One such break recently released more than 90,000 gallons of fresh drinking water before authorities could get it turned off.
And the cost of wasted water is nothing when compared to the property damage and the cost of clean up and repair.
So what is the solution?
Should we stop conserving water so that the water pressure in the pipes goes down?
Can we afford to repair all the city's water pipes?
Stay tuned for the next chapter in the continuing saga as California conserves water to protect the Sacramento Delta Smelt fish.
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It's no longer even laughable...it's just plain sad. When will it end? Check out this link a friend sent me today - http://www.youtube.com/watch_popup?v=G44NCvNDLfc
ReplyDeleteIf I may play Devil's Advocate for a minute, but, what if the State's Water Conservation Program isn't the major culprit for this sudden rise in bursting pipes? Now, I’m not an established engineer with 20+ years of engineering experience like our beloved MacNiven, but…if water conservation is allowing “… (the) reduced water demand (increase) the amount of water in storage tanks and increases the pressure of the water in the water distribution system…” wouldn’t the water distribution system be designed to handle maximum pressure at maximum water capacity? Unless the city’s water pipes were designed by the Chumash Indians and Spanish settlers back in the late 1700’s, wouldn’t the engineers put several safety factors in place when designing the city’s pipes? Also, why is L.A. the only major California city to be affected by a water conservation problem, shouldn’t other major CA metropolitan areas be suffering as well? (Why isn’t there any major pipe failure stories coming in from San Diego, or San Francisco, which is an older metropolitan city than L.A.?)
ReplyDeleteWater conservation, or not, LADWP (Los Angeles Department of Water & Power) would be the first to acknowledge that there is a problem. “(Recently), DWP officials say the number of leaks was not out of the ordinary. (Los Angeles) City pipes fail about 1,400 times a year, a rate per mile of pipe that is actually much lower than in other big cities. But what is unusual is the increase in ‘major blowouts’ in which pavement is ruptured and the leak causes problems.” (Source: Los Angeles Times, 9/16/2009) So, city pipes requiring maintenance and repair are nothing new for the aging system of the City of Angels, but what is new is the severity of the problem that is damaging more than just the pipe.
In my humble opinion, the city’s pipe bursting epidemic is the result of a perfect storm that is made up of the following components:
• The city’s politicians (and all politicians for that matter) focusing on matters that help their own political ambitions and neglecting the city’s basic needs/maintenance.
• DWP Union Chief, Brian D’Arcy, monopolizing the DWP’s workforce which results in controversial contracts and lucrative raises for DWP employees that hinders the city’s budget. (Source: Daily News, 9/8/2005)
• DWP executives failing to control the department’s budget from the meddling by city politicians and the DWP Union Chief, which has resulted in negligence to the city’s infrastructure (not just the water distribution system). When major problems do occur, rate hikes are needed to compensate, which are denied by the city taxpayers, crippling DWP even more.
• The “major (pipe) blowouts” are concentrated in the southeast corner of the San Fernando Valley, the Miracle Mile area, and West Hollywood; all of which are located directly over the Raymond and Santa Monica faults, which according to the USGS, are in continuous tectonic motion (albeit, minor compared to more “famous” faults, such as the San Andreas fault). After many years of the land shifting around the pipe, additional stresses to the water pipe would be produced, in addition to the Hoop Stress it normally encounters.
I’m sure there are more than just these 4 reasons, but I would like to know what our respected MacNiven thinks of this counter-argument.
-VB on XBL
My Anonymous Friend (VB on XBL) makes some good points and also brings additional claims of political interference. While he/she claims not to be "an established engineer", the use of the term "Hoop Stress" reveals at least a technical background.
ReplyDeleteA quick study of the age of water mains in California shows that many are 50 years old and some over 100 years old, such as the 6 inch main that broke this year at Nob Hill in San Francisco. Pipe materials for these older water mains include galvanized steel and concrete. There are even examples of water pipes made from wood into the 20th century. They are very different than the PVC pipes we see in installed currently.
While safety factors on hoop stress and other stresses were certainly considered in the pipes when they were installed, the extreme environmental damage from years of rust and neglect (as VB mentions) were likely not considered. I would submit to you that the normal leakage from these aging pipes (which is not severe enough to be considered a "blowout") is a substantial amount of water, and an estimate of which would likely concern many of our environmental friends. One positive note about leakage is that it keeps the water tables full and supplies ground water for wells in the area, although the pollution might make it undrinkable.
Contrary to a claim by VB is that LA is the only area to have problems with breaking water mains as a result of recent conservation efforts. A quick Google search shows an increase in the number of broken water mains in San Fransico as well as San Diego, all of which I submit, are the direct result of water conservation and old water pipes.
Now VB brings up some valid points about the impact of both government and union interference with the necessary maintenance and replacement of aging water pipe systems. MacNiven has no great love for polititions and even less for unions, that suck money from legitmate projects to satisfy their own greed and desire for power and control. But that is another subject.
The suggestion that these blowouts could be caused, at least in part, by earthquake faults is interesting, but keep in mind that tectonic motion has been with us for millions of years. I must agree with VB that any environmental impact which weakens these old pipes contributes to their failure.
In summary, I continue to believe that the source of the problem of increased water main blowouts is government interference (including VB's addition of political and union interference as well) with a system and workforce that would normally take care of itself through normal water pressure, proper maintenance and pipe replacement.
- MacNiven