For the first time since NBC 7 Responds started asking the Public Utilities Department questions about high water bills, the city admits mistakes were made.

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.

According to Bianes, the city discovered this problem Thursday morning and believes this is an isolated incident but will be investigating other areas of the city.

“We will continue to look at all meter reads,” Bianes said, “as a matter of fact, this month we are going to go out and read the rest of the city’s [meters] as part of the billing cycle to verify no other misreads were done due to this human error.”

The “human error” was a city employee who’s meter-reading route went through the neighborhoods that were impacted. Bianes said the employee no longer works for the city.

“That’s a personnel matter,” Bianes said, “I’ll basically state we have human error, where people enter in the meter reads and that may have caused what happened here.”

For the homes where misreads were determined, the city said customers were overcharged an average $303. If customers overpaid, the city said they will be issued a check if the amount is over $50. If the amount is under $50, customers will see a credit on their bill.

NBC 7 Responds started asking the Water Department questions about high water bills back in August when homeowners were questioning high water use that was impacting their bill.

The city had told NBC 7 Responds and customers a variety of reasons for the high water bills, including water leaks, over-watering, visiting relatives for the holidays and changes in the number of days in a billing period.

Now, Bianes said new measures will be put in place to hold Public Utilities Department Supervisors accountable for their work, specifically requiring them to personally sign-off on daily reports from meter readers.

Earlier this week, Councilmember Barbara Bry suggested the Public Utilities Department change their policy and allow 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.

At the news briefing, Bianes confirmed the department was putting this policy in place, saying, “We will not shut off any water until the resolution with the auditor has been completed.”

The city said they have brought in more employees to meet the demand of higher than normal customer complaints.

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.

UPDATE: A previous version of this story incorrectly stated the news conference took place on Wednesday when it took place on Thursday, February 8.