UPDATE: You can read the full report on the water pipeline breaks here (WaterPipeBreaks.pdf)
The bad news keeps coming for the DWP — even on a day when its management was boasting to the world how the public had reduced water consumption to a 32-year low but couldn’t answer questions about the impact of conservation on its revenue.
Professor Jean-Pierre Bardet, the head of USC’s civil engineering department, said a team of scientists he led has determined that DWP’s requirement that lawns only be watered on Mondays and Thursdays caused uneven pressures that stressed pipes and led to the rash of blowouts of water mains last summer and fall.
”The bottom line is, you want to create a more even usage of water
pressure so you don’t have a sudden drop of water pressure at a given
time of the day,” said Bardet, told Councilwoman Jan Perry’s Energy and Environment Committee Tuesday afternoon.
The ream’s report said: “Those water pressure drops on these days were caused by an increased
water flow during the watering of lawns. As a result,
the cyclic levels of water pressure increased and accelerated the metal
fatigue failures of aged and corroded cast-iron pipes.”
The DWP’s initial reaction was to deny the report and try to deflect responsibility for an ill-conceived water rationing policy, according to statements the utility released. Here’s KPCC’s updated report:
The DWP has released a statement about Bardet’s report,
indicating nobody there has yet read it. “The Department believes
corrosion is the indisputable and primary factor in most of our water
main breaks, including those from last September,” the DWP statement
says. “We believe Dr. Bardet’s findings will support this position.”
DWP says its own internal report blames blowouts in September
2009 on system pressures created by repairing breaks from earlier in
the summer. “It is the Department’s position that the operational
changes to accommodate City Trunk Line repairs resulted in ruptures on
mostly cast iron mains, which accounts for the increased severity of the
breaks in the weeks that followed,” the report says.
Let’s hope the mayor delivers on his promise by Thursday and cleans out those at DWP responsible for its many failures and bring transparency and professionalism to the nation’s largest municipal utility.
Of course, you’ll have a hard time find anyone to book your bet on him delivering what he has promised.