Logo: University of Southern California

Astani Department Chair Shapes New L.A. Water Rationing Plan

Jean-Pierre Bardet's role in investigating water main breaks, and recommending a new plan is widely reported
Eric Mankin
July 03, 2010 —

Professor Jean-Pierre Bardet
Chair, Sonny Astani Department
Director, USC Center on Megacities

"These weak links [in the pipes] keep appearing, and they are here now, and they are ready to break and create another rash in the summer if we don't prevent the [pressure] fluctuations," [Bardet] told the board in May.

DWP officials were skeptical of Bardet's conclusions at first... Later, however, the senior assistant general manager for DWP's water system, James McDaniel, agreed that changing the rationing schedule "would reduce the magnitude of pressure fluctuations throughout the DWP water distribution system while still providing the necessary water conservation levels."

...un estudio de la Universidad del Sur de California (USC) concluyó que limitar el riego (la actividad que consume más líquido) sólo unos días afectó los conductos de la ciudad.

El resultado ha sido la ruptura de tuberías en distintos sitios de esta metrópoli, precisó Jim McDaniel, responsable del sistema acuático del Departamento de Agua y Energía (DWP).

... Experts searching for explanations said one cause of the problem could be that the twice-weekly watering caused surges in pressure in the region's 7,200-mile network of pipes, some of which are more than 100 years old.

When that theory was first floated in September by Jean-Pierre Bardet, chairman of the University of Southern California department of civil and environmental engineering, DWP officials expressed skepticism.

But after a research team led by Bardet released a study formalizing the finding, the citizen commission applauded the decision and said the new approach "might be helpful to other cities with conservation programs."...

Dr. Jean Pierre Bardet of the USC School of Civil Engineering attributes it to the city's two-day-a-week watering-rationing schedule. And Tuesday, he warned if that doesn't change, there'll be more blowouts.

"We predict that if we don't do anything, what we are seeing in the summer of 2009 will happen in the summer of 2010," said Bardet.

With Bardet's warning in mind, the Los Angeles Dept. of Water and Power Board of Commissioners Tuesday voted unanimously to change the rationing schedule.

The proposed changes come weeks after a study led by Jean-Pierre Bardet, chairman of USC's Department of Civil and Environmental Engineering, found that banning residents from turning on their sprinklers except for a few hours on Mondays and Thursdays was a major factor in the 101 water main breaks reported from July through September last year -- double the normal number for that time period.
The proposed changes come weeks after a USC study found that DWP's water rationing schedule created drastic changes in water pressure that put stress on corroded cast-iron pipes and caused them to break, causing severe flooding in several areas of the city.
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