Last Tuesday, people in the Carrollton area woke up to what must have looked like a catastrophic flood (or a levee break) — 2 feet of water in some places, submerging cars. Others nearby didn't notice anything until they turned on the tap to brush their teeth or make coffee (or, worse, flush the toilet): low water pressure.

  A major water main had broken in the wee hours, and once again the New Orleans Sewerage & Water Board (S&WB) was caught flat-footed. Response to the crisis itself was quick enough, but New Orleanians who had been through this drill before wanted to know if the neighborhood, or the city, was now under a boil-water advisory. The answer, the city said, was "no."

  Until it became "yes."

  Nearly six hours later, the S&WB issued a boil-water order for much of Uptown (including unaffected areas), saying it wasn't in response to a particular contamination threat, but "out of an abundance of caution."

  Caution? How cautious is it to wait six hours — six hours during which residents spent their morning drinking water, bathing in it, cooking with it and generally behaving like Americans in a city with modern infrastructure. It's difficult to imagine anyone who hadn't come in contact with the affected water by 11 a.m., when the boil order was issued.

  Today's S&WB inherited a century-old, decaying infrastructure. Certainly no one wants the agency to jump the gun and issue boil-water orders every time the pressure dips. (There have been at least five boil orders in the last few years.) But a problem with the water system is either a public health emergency or it's not, and waiting hours to issue a boil-water advisory isn't "an abundance of caution." It's the opposite — and one that sends mixed messages to residents and businesses.