NASHVILLE, Tenn. -- Having enough water flow to put out a fire was the last thing Julie Carter had on her mind when she and her husband began building a log cabin in rural Davidson County.

Video: Not All City Hydrants Meet Minimum Flow Standards

Then they did a flow test of the fire hydrant just down their driveway.

"I'm still worried," said Carter. "I'm gonna be worried until they find a solution to the hydrant problem."

Hydrants must have a certain minimum flow to fight a fire. Nearly 600 hydrants don't meet even minimum national and international standards for water flow.

"Obviously," Carter said, "if we had a fire, how are we going to have this house put out?"

The low-flow hydrants aren't a secret to firefighters. The city recently adopted new national fire safety standards, requiring all new homes built up to 3,600 square feet be protected by a hydrant with a minimum flow of 1,000 gallons per minute.

The city adopted that 1,000 gallon minimum standard from the National Fire Protection Association and the International Fire Code.

The 586 low-flow hydrants the Channel 4 I-Team found flow less than 500 gallons per minute, which is only half of the minimum accepted flow.

While the vast majority of hydrants in Nashville have enough flow, the 586 low-flow hydrants represent protection for thousands of homes.

• Hermitage ZIP code 37076 has 121.
• Belle Meade ZIP code 37205 has 24.
• Goodlettsville ZIP code 37072 has 39 low-flow hydrants, one of which is outside Carter's home.

The city is requiring new houses built around these low-flow hydrants be equipped with sprinklers.

"That's our only water supply, other than what's in our booster tanks," said William Curran, Nashville Fire Department deputy chief.

Tennessee has the fifth-highest number of fire deaths in the nation.

"Are we going to be alright?" Carter asked. "Are they going to get to us in time?"

Do some people have better fire protection based on the hydrant in front of their homes?

"Again, there's so many variables that play on that," said Curran.

Variables, firefighters said, such as how quickly firefighters could get to the house and what the house is made of.

Regardless, this report, out this month from the U.S. Fire Administration, addresses the need for water supply for effective fire protection.

Two of the main contributors to the report said the low-flow hydrants in Nashville are a problem.

Ken Dungan, a fire protection expert, said that you should be concerned if you live in front of a low-flow hydrant that there may not be enough flow to fight a fire.

"If you're not home and the first notification is smoke or fire coming out of your roof or out the window," Dungan said, "by the time the water department gets there, they won't have adequate water to do anything but protect the foundation."

Because her new home sits in front of one of the low-flow hydrants, Carter had to have sprinklers installed. Her mother-in-law lives next door in an older house not required to have sprinklers. They share the same low-flow hydrant.

The I-Team continues its investigation about how Nashville's fire department plans to handle the challenge Friday on Channel 4 News at 6 p.m.

Related Link:

The Metro Water Department lists 586 hydrants flowing below 500 gallons per minute, well below the national and international standard for minimum water flow for fire hydrants. This PDF document provides the best data possible for the locations of those low flow hydrants. The Channel Four I-Team removed data that wasn’t clear or concise, so the locations for every hydrant are not in this document.

Low Flow Fire Hydrants By Zip Code (pdf)