ST. PETERSBURG — Get ready for another increase in utility rates. And another. And another.

City Council members approved a utility rate hike Thursday that would start in October and raise utility bills between $7 to $10 each. That was only the first reading. A public hearing is scheduled for Aug. 23, when the final vote will take place.

Should it pass, it will be the second rate jump in 2018.

Last year, council approved a 25.5 percent increase in reclaimed water rates that went into effect Jan. 1. That was the first in a series of hikes that could double reclaimed water prices over five years.

Residents can expect to see their total utility bills — including reclaimed water, sanitation, potable water — to increase about 50 percent between now and 2023, according to data shared by city staff.

Council member Ed Montanari said people should expect to see those bills rising each year beyond, as well.

"I wish it wasn't true, but I believe this is the new normal," Montanari said. "Just because of where we are and the amount of money we're going to spend to invest in our infrastructure."

Montanari was referring to the amount of debt the city has had to take on to pay for repairs to a sewage system that discharged up to 1 billion gallons during the 2015-16 storms.

As a result, the state mandated the city spend $326 million to repair and upgrade the ailing system. Mayor Rick Kriseman refers to these repairs, as detailed in a consent order with the Florida Department of Environmental Protection, as the Kriseman Infrastructure Plan.

The hundreds of millions required for repairs is a major factor in rising rates, Montanari said.

The increase voted on Thursday would raise water and sanitation bills, on average, by 7 percent.

Customers who use an average of 4,000 gallons a month, including reclaimed water, will see an increase of $9.78, according to a memo from Kriseman's office to council members.

For those who don't have access to reclaimed water, rates will rise about $6.91 a month.

Another driving factor behind rising rates is an attempt to increase the amount of cash the city uses to make payments. Currently, the city relies heavily on debt to pay for capital projects. The goal, staff said, is to make that split 50/50, cash and debt. Doing so could save more than $300 million in interest rates over 30 years.

"That's money that can go back into our system," Council member Steve Kornell said. "Long term, that's going to be good."

City staff also presented council members with a proposed change to stormwater rates that would start April 1, 2019.

The change — which is separate from the utility increase — would move the city to a tiered-rate system based on the square footage of each property that is impervious to water, such as rooftops and asphalt. That would replace the current flat-rate system where each property owner pays the same set fee.

"It really addresses fairness and equity in our rate system," Council member Darden Rice said. "Everyone is assessed the same stormwater fee, no matter the size of your lot or the house or the permeable surfaces. The tiered system is a step forward in fairness."

Those who have more square footage on their property that water can't soak through will pay more. Those property owners with fewer impervious surfaces will pay less.

Some residents are already unhappy with the proposed changes. The city's posts to the NextDoor app alerting residents of the stormwater and utility changes on Thursday's agenda drew a flood of criticism. Many were outraged that the city could end up raising utility rates twice in the same year and, for some residents, changing stormwater rates could bring another increase.

"I think anything that gets thrown in the same bucket as utility rates increases as its first introduction is probably not going to get a warm welcome," Rice said. "There may be a few people with larger lots who may not appreciate the increase, but it's really what's fair."

Which homes would fall into which tiers? Public works spokesman Bill Logan said the city will soon explain that process.

"Right now, we're just getting out the initial word out of what's going on," Logan said. "There hasn't been any delineation of who's paying what. That comes next."

Compared with rates in other nearby cities, the proposed utility increase puts St. Petersburg on the higher end of the spectrum. Tampa, which hasn't raised rates since 2011, remains the lowest in the region.

There will be other opportunities for the public to weigh in on the tiered stormwater system, Logan said, but those dates have not been set.

Contact Caitlin Johnston at cjohnston@tampabay.com or (727) 893-8779. Follow @cljohnst.