During the month of October, the number significant water main breaks in the 7200 miles of pipes that comprise the LADWP water system was much lower than that experienced during the month of September.  In October, the DWP experienced 29 significant breaks and the number of total leaks and breaks was about average for this time of year. 

Leaks occur in our system on average about four times each day and the rate at which they occur in LA is well below the national average.

During the month of September 2009, the Los Angeles Department of Water and Power experienced an increase in the severity of pipe breaks in its water distribution system.  It is not known whether what occured was due to any specific cause or is nothing more than a statistical aberration. The large City Trunkline rupture near the intersection of Coldwater Canyon Avenue and Ventura Boulevard, which occurred on September 5^th, coupled with the very visible smaller 6-inch main break two days later involving an LA Fire Department engine, placed heightened attention on much smaller routine breaks that occur every day in our system. It is important that we keep the discussion of the recent main breaks in their proper perspective.

The breaks that we experience in our system occur primarily in mainlines, which comprise ninety percent of the 7200 miles of pipes in our water system.  Mainlines are pipes with diameters of 24 inches or less.  They supply water directly to the individual customers’ service connections.

LADWP experiences approximately 1400 water main leaks and breaks per year.  Approximately 200 of these can be characterized as breaks requiring more significant repairs.  These are leaks and breaks that impact customers, cause street closures and/or require street repairs in excess of 100 square feet.  These breaks occasionally generate media attention, but frequently go unnoticed.

We experience on average approximately four breaks a day, which is an extraordinarily small number given the size and complexity of our water system. Overall, our system average per 100 miles of pipe is 19.85 leaks and breaks, and is below the national average of 25 per 100 miles of distribution pipe.  Additionally, most breaks or leaks require small spot repairs, not full replacements.

For September 2009, LADWP experienced 44 breaks requiring more significant repairs, out of 152 total breaks and leaks.  This number of leaks approximated the usual number expected in our system, but the 44 represented an increase in the size and impact of breaks seen historically.

The breaks during the month of September have resulted in minimal loss of water service to customers. Typically, customers experienced a loss of water service for a period of approximately 6 hours or less to an average of 25 customers per incident. The total number of customers affected by these is less than one-half of one percent of LADWP’s 680,000 water customers.

The amount of water lost during these main breaks has also been minimal.  For the first three months of mandatory water conservation (June, July & August,) Angelenos conserved 30,000 acre feet of water.  This equates to 10 billion gallons. The total water lost in the September main breaks is less than ½ of one percent of the water saved this summer.

Main breaks are part of the normal operations of any water system and LADWP has been working proactively to identify the pipes most in need of repair and replacement. 

We have 14 full-time crews dedicated to mainline replacement.

In the past two years, LADWP has replaced 160,000 feet of mainline and has set a goal of replacing 110,000 feet in the coming year.

The program is intended to minimize main leaks, service interruptions to the customers, and potential property damage. Over the long-term, the program will also reduce water main maintenance costs, improve water quality, reduce water loss due to leakage, and improve water flow for fire emergencies.

LADWP is conducting a full investigation to determine the cause of the increased severity of the September breaks.

The investigation includes data extraction and geographical analysis of each break, visual inspection of the pipe, bedding and soil conditions at each leak location, lab analysis of pipe samples collected, inspection of service zone interconnections, and exploration of the geophysical conditions.

As a part of the investigation, LADWP will rely on the expertise of our employees, developed over decades of experience in water system excellence, in partnership with subject matter experts from the University of Southern California Megacities Project, Jet Propulsion Laboratory, Cornell University and others. 

We will not speculate about causes to the recent increase in the severity of pipe breaks.  We will wait for the facts and evidence discovered through our investigation to lead us to conclusions – not form them before we have evaluated the facts and completed our investigation.

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