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Water Main Leaks Don't Let Up, Even During A Drought

Ed Osann

Posted February 15, 2014

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We've all seen the big water main breaks on the evening news or on YouTube.  Thumbnail image for SD Break 2009-resized.jpgBut only a small number of water main breaks actually make the news.  And all the main breaks put together are only a fraction of the total amount of water being lost every day from water utility pipes.  Much more water is lost from leaks that continue unseen for months and even years. 

    At right: Water Main Break, San Diego, 2009

                  Photo Credit Flickr: Jun 

California is estimated to lose about 10% of its supply of treated drinking water due to leakage from water utility pipes.  These losses are an unrelenting “tax” on the water system and its customers – robbing families and communities of clean water year after year.  Even during an emergency, a Governor or Mayor can no more effectively order these losses to cease than King Canute of old could order the ocean’s tide to go out.

Things may be starting to change, however.  Under a recommendation recently made by a State panel to the Legislature, California would become the Nation’s sixth state to require urban water suppliers to annually report the losses from their water distribution systems using a consistent methodology and format developed by the American Water Works Association, the trade association for drinking water professionals and utilities.  Georgia, Rhode Island, Tennessee, Texas, and Wisconsin already have such requirements in place, and Maryland, New Mexico, and numerous other states have moved in somewhat similar ways to strengthen and standardize water loss reporting in recent years.  In the grip of an acute drought, California is now scrambling to catch up.

LA break 2009-resized.jpg               Above: Sink hole created by a water main break, Los Angeles 2009 

                                           Photo Credit: Nick Ut/AP Photos

Many water suppliers in California already use the AWWA format voluntarily as an aid to monitoring the status of their infrastructure and for planning capital replacements and maintenance strategies.  One of the key benchmarks of performance that is generated by the AWWA method is the volume of water lost from the system divided by the number of customers connected to the system -- expressed as “gallons of water lost per service connection per day.”  This allows for a fair comparison of large and small utilities.  NRDC recently took a look at the first 40 or so water utilities that completed their assessments for 2012, and found a wide range of performance, from a low of about 10 gallons per customer per day to a high of over 130 gallons per customer per day.  The latter figure is larger than the total water use of some small, frugal households.  Cities losing this much water before it ever reaches customers are in a poor position to advise customers to conserve.

Water loss monitoring-resized.jpgEngineers are fond of saying “You can’t manage what you can’t measure,” and for decades water losses from buried water mains were accepted as an inevitable cost of doing business that was not worth worrying about if kept under 10%, 15%, or 20% -- different rules of thumb were used in different states.  Now AWWA is telling its member utilities to forget about percentages, and instead calculate the volumes of water losses, the cost of loss reduction strategies, and the amount of water losses that might be cost-effectively prevented.  For California, a first order estimate is that the loss of about 350,000 acre-feet of treated drinking water currently going to waste each year could be cost-effectively saved – a volume that is nearly double the entire annual water use of San Diego, the state's second largest city. 

Left:  Acoustic monitoring, a better way to find leaks

Photo: Vivax – Metrotech Corp

With California now facing acute water shortages after the driest year in its recorded history – and getting a glimpse of the “new normal” produced by a changing climate –  the time to measure, manage, and eliminate the unnecessary waste of water right under our feet is now.  As consumers, we have many ways to many ways to avoid wasting water around our homes, including the "Nine Ways to Save" listed here.  But out in the street, it's the utilities' job to manage the pipes they own to reduce leakage and stop wasting this essential resource.




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Greg GartrellFeb 18 2014 11:23 AM

No agency loses 10% from"leaks". The correct terminology is unaccounted for water (UAW) and is in large fraction meter error. Small house meters tend to run low and get worse with age. The water is not lost just not metered directly. Before you scream replace all the millions of meters at high expense, the result of that would be nil. Rates could go down an average of 5% (after they go up to pay for the new meters) while the measured amount goes up 5%. Net result: you get to find something else to worry about but no water was saved. You can save more by getting idiots to stop driving into hydrants.

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