Rationing back as top theory in water main breaks

Illogical as it sounds, a panel of experts convened by the city has concluded that last year's siege of water main breaks was triggered by the DWP's Monday-Thursday watering restrictions creating higher pressures on aging pipes. You'd think that pressure on water mains would either average out across the city or fluctuate through the day and by season — based on everything from hot days creating more demand to people flushing during commercials in the Super Bowl. But the panel said that with sprinkler use concentrated on Mondays and Thursdays, abrupt pressure changes caused breaks in older, corroded water pipes. Last year, the DWP pooh-poohed the notion that sprinklers could cause noticeable pressure spikes, blaming instead corroded pipes, minor increases in pressure due to an unusually full reservoir and fluctuations after that big trunk line ruptured in Studio City. Also, it wasn't that long ago that DWP chief S. David Freeman said stats showed there wasn't any appreciable jump in water main breaks anyway.

Add DWP: Mayor Villaraigosa appointed Eric Holoman, president of Magic Johnson Enterprises, to the opening on the DWP board. Also, the department announced that water use in February fell to a 32-year low.

Cartoon: Steve Greenberg