As scientists predict rising sea levels will make water-laden places like Jacksonville more vulnerable to flooding, the city is moving to tighten regulations on new construction in areas most at risk from water overflowing creeks and rivers.

While the focus is on new construction, the changes might have a spin-off benefit for current homeowners by reducing flood insurance premiums. The National Flood Insurance Program gives discounts in cities that put extra measures in place.

Legislation filed this week with the City Council would expand the area next to waterways where plans for new development would undergo heightened scrutiny by the city.

Another provision says that in flood hazard areas where flood insurance is mandatory, the bottom floors of new buildings would have to be at least 2 feet above the base flood elevation — double the current distance.

The legislation (2019-331) also would establish requirements for fill dirt that is brought to lots. The fill dirt must meet standards for absorbing water so the fill doesn't result in water running off and creating headaches for neighboring property-owners.

The legislation is based on the first batch of recommendations from a Storm Resiliency and Infrastructure Development Review Committee formed in February.

"I think it is a step in the right direction," City Council member Lori Boyer said when the Jacksonville Waterways Commission unanimously backed the legislation this week.

City Council member Jim Love, who is serving with Boyer on the resiliency committee, said a storm like Hurricane Irma in 2017 still will cause widespread flooding, but the city can strive to lessen the damage.

"If we have another Irma, we're going to flood again," he said. "It's just that hopefully some things are done to mitigate it."

Jacksonville has room for improvement, according to National Flood Insurance Program ratings.

On a scale of 1 to 10 for flood prevention measures, with 1 being the best, Jacksonville has a score of 6 in the community rating system. Based on that score, Jacksonville flood insurance policy-holders get a 20 percent discount for coverage in high-hazard areas.

If Jacksonville improved its community rating score to 5, that would boost the discount to 25 percent, and if Jacksonville advanced to a score of 4, the discount would grow to 30 percent. The highest possible discount is 45 percent.

The storm resiliency committee has been studying Florida cities with higher scores as a model for changes in Jacksonville.

"I guarantee it can't hurt, and it might help," Love said of the potential for insurance discounts.

He said some people are paying a $1,000 annual premium for flood insurance, so they would save $100 if the city improved from a 6 to a 4 in the rating system.

The city currently tightly regulates construction in a floodway, which is the area covering a waterway's channel and the nearby land were water spreads during floods. The legislation would expand the regulation by creating "floodway setbacks" with an additional 25 feet of buffer zone from the edge of the floodways.

In a special flood hazard area, the finished floor of a new building would have to be at least 2 feet above the base flood elevation compared to 1 foot now, so flood water would have to rise higher before it gets into the building.

Love said those extra levels of protection against flooding will be needed as climate change continues.

"We're moving in the right direction," he said, "and with climate change, we have to do this."