The city admitted Thursday to overcharging hundreds of water customers by as much as $300.
In a news conference on Thursday, Public Utilities Department Director Vic Bianes said his agency investigated 3,000 meters in the Carmel Valley, Mira Mesa, Rancho Bernardo and Rancho Penasquitos neighborhoods and found 343 readings in the November/December billing periods were misread.
Officials are linking the problem to one meter-reading employee who no longer works for the city.
Mira Mesa homeowner Steve Martin is one of 343 who are victims of a misread water meter.
"We usually pay about $150 to $175 for two months and it went to almost $700," Martin said. "Almost four times what it normally is."
"At first, I kind of panicked on it and go well, I'm going to look around my house and see if I've got anything leaking or anything like that. Didn't have anything leaking," he added.
Homeowners dozens of miles away from the zones the city investigated claim they also saw a spike, and are wondering how widespread the problem really is.
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NBC 7 spoke to Beverly Bradley in Pacific Beach, and other homeowners in Paradise Hills, Hillcrest, Del Mar and Pacific Beach who are all experiencing the same issue.
"All of a sudden, there was this big jump and it was more than double what it usually was," Bradley said. "And the thing that was strange about it, it was during a time when we had rain, so I turned the sprinklers off."
Like many others, Bradley said she called the city and questioned the charges.
She then had to pay to have the meter checked and a plumber to sign off, saying there were no leaks on her property.
"Just to protest the bill, it was $160," she said.
Bradley received a credit for having the meter checked.
The Public Utilities Department is allowing water customers who are challenging high bills to hold-off on paying until a city auditor review of the water department's billing practices is complete.
For customers who think they were billed for more water than they used and who live outside of the neighborhoods where these misreads were confirmed, the Public Utilities Department is asking they contact the agency at 619-515-3500.