Louisville legislators may soon get their first chance to craft policy around the findings of an acclaimed study on the city's urban heat island.
A Metro Council committee is in the midst of a multi-year effort to rework the city’s 800-page land development code, and one soon-to-be-discussed item deals with regulations guiding parking lot developments.
Parking lots are cited in the recently released study as an element contributing to the city's urban heat island effect.
The term “urban heat island” refers to the difference in temperature between urban and rural areas. Brian Stone of Georgia Tech — one of the foremost UHI researchers in the country — conducted the study for Metro government. He has previously found that Louisville is home to one of the fastest-growing heat islands in the country, which has contributed to heat-related deaths in the city.
Temperatures can be up to 20 degrees higher in the downtown core compared with more suburban areas of Jefferson County, according to Stone's research. Combating a heat island means planting more trees, using more reflective building materials and being mindful of energy consumption.
But getting more trees into a parking lot can be difficult, said Barbara Sinai, an independent architect who served on a 28-member subcommittee that analyzed the city's land development code to craft recommendations on how it should be updated.
"The developer wants more parking spaces and people want more green," she said. "It's a difficult balance."
Still, the subcommittee recommended just that — more trees for future parking lots. Their recommendation is set to go to the council's ad hoc committee on the land development code in the coming weeks.
It calls for developers to plant up to 25 percent more trees in parking lots that will exceed the minimum number of required parking spaces. Specifically, one tree must be planted for every four parking spaces beyond the required minimum.
Putting more trees in parking lots garners praise from Brent Fryrear, director of the Partnership for a Green City. They can help with heat and rid the air of harmful toxins coming from cars and asphalt, he said.
Fryrear said there are other ways to combat a heat island effect, like trading asphalt for concrete or other permeable paving materials, and applying a reflective coating to existing paving.
But those methods aren't the focus of the subcommittee's recommendation to the council.
According to those recommendations, developers may have the tree-planting requirement waived or modified if they opt to use alternative design or material if the alternative "offers greater environmental benefits than those associated with" additional trees.
Just how much alternative material, like concrete, will be required to have the tree-planting regulation changed is unclear.
When it comes to combating heat islands and installing environmentally friendly infrastructure in a parking lot, it's tough to beat trees, Fryrear said.
"There's a lot of ecological benefits with the trees," he said.
The subcommittee recommendations also eliminated language in the land development code requiring developers with parking lots on their properties to install specific amounts of concrete or permeable surface material to projects exceeding minimum parking requirements.
Councilman James Peden, a Republican who represents District 23, questioned whether eliminating those requirements from the land development code could hurt efforts to address the heat island dilemma.
"If we are changing it at all, I don't want to be the guy who takes out environmentally friendly options," he said.
Peden said trees are a welcome amenity in parking lots, but they alone don't solve the problem.
Greater Louisville Inc., the city's chamber of commerce, did not respond to a request for comment about the proposed changes to the land development code.
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