Even as DWP crews scrambled to repair a water main break in Winnetka, a panel of experts reported Tuesday that corrosion, not the city's conservation program, was to blame for a spike in pipeline ruptures that have disrupted traffic and engulfed a fire truck.
The Department of Water and Power released the long-awaited report - developed by experts from the University of Southern California, Cornell University and the Jet Propulsion Laboratory - which blamed the breaks on corroded portions of the aging system.
"Due to the historical methods of water main installation, it is expected that pipelines will continue to corrode, deteriorate and leak over time to a point where further capital investments will be needed in order to maintain an equal level of service to our customers," the report stated.
The city has seen a higher-than-usual number of major water breaks this year, including the one reported at 2:37 p.m. Tuesday that caused minor flooding in the 1900 block of Hart Street.
However, a break earlier this fall at Coldwater Canyon Boulevard flooded the neighborhood and closed businesses for weeks, and another in Valley Village opened a sinkhole that engulfed a firetruck.
In releasing the report, DWP officials said the panel determined that the city's conservation program, which limits lawn watering to Mondays and Thursdays, was not to blame for the pipeline problems.
Some experts had theorized that the watering restrictions overburdened the system on the allowed days and may have contributed to the breaks.
The breaks did increase the pressure on other lines, causing new damage while the breaks on cast-iron pipes did appear to be higher this year than in past years, the report said. Cast-iron pipes appear to cause greater street damage compared to other pipes.
An aide to interim DWP Director David Freeman said the report speaks for itself. It will be submitted to the City Council for review.
"It pretty much says everything we could say on this," DWP spokesman Joe Ramallo said.
The report noted the utility stepped up its pipeline replacement program in 2007 and has a $5 billion improvement program under way.
Prior to that action, the outside experts said the DWP had focused primarily replacing pipes only when they ruptured.
"However, that replacement rate corresponded to a replacement cycle for water mains of well over 400 years," the report said. "This means it would take over 400 years to replace all the pipes in the DWP water system."
The new program will replace 200,000 feet of pipes each year between now and 2012 - reducing the replacement cycle to 180 years.
The DWP estimates the current age of its pipes is 70 to 100 years old.
The report noted that the utility has added staff, but needs to do more - a factor which might cost ratepayers more money to repair all the pipes that are needed.
The report drew criticism from Jack Humphreville, who serves on the Neighborhood Council Oversight Committee of the utility.
"The problem that we and all the public have is the lack of credibility of the DWP," Humphreville said. "A report like this just shows, again, why we need a ratepayer advocate at the DWP.
"When you read that they have had a 400-year replacement cycle, it makes absolutely no sense. And, if they have the money now, why not hire more outside crews so we can get the work done faster and cheaper?"
Other recommendations include an annual report on replacement programs, expansion of a corrosion protection program on steel pipes, updating records on the leakiest pipes in the system and developing a priority list of pipe replacements.