In Virginia, staff at the Hampton Roads Planning District Commission faced a dilemma familiar to many local governments: a crumbling asphalt parking lot that needed repair. Instead of replacing it with more dark blacktop, the commission chose a different approach, completing a new lot last year that incorporates porous concrete panels and landscaped sections with native plants and recycled materials, according to the Associated Press.
Jill Sunderland, the commission’s senior water resources planner, described the goal of the change in practical terms. Sunderland said the design lets “the rain infiltrates faster than it can puddle and stop on the surface,” and she also said people could feel the difference on hot days. “You notice too, that it’s cooler,” Sunderland added, saying the revised lot feels more inviting as well.
The Hampton Roads project is one example of a wider shift underway in cities and other organizations across the U.S., as officials look for ways to address both heat and flooding. The AP reported that many parking-lot designs made from impervious, dark pavement can intensify urban heat while also limiting how quickly rain soaks into the ground—problems that are becoming more urgent as climate change worsens extreme weather.
One set of strategies focuses on cooling. The AP reported that parking can take up a large share of land in some downtowns, and that experts say many spaces sit empty much of the time. With grants and other support sometimes available, some cities and businesses have moved to replace or transform hardscape parking areas using measures such as reflective surface coatings, vegetation that absorbs energy and releases moisture, and landscaping requirements that drive shade over time.
In California, Sacramento requires parking developers to plant enough trees to shade half the lot within 15 years of construction, and other cities have adopted green-area requirements, the AP said. Some places also use solar panel installations as shade structures, combining energy infrastructure with efforts to reduce how much heat the pavement absorbs.
Another strategy targets stormwater runoff. When rain cannot soak through pavement, runoff can carry pollutants such as oil and heavy metals into nearby waterways, the AP reported, citing Vincent Cotrone. More permeable materials—ranging from lattice pavers that can allow grass to grow to other porous and interlocking designs—are intended to let water filter through instead of washing across impermeable surfaces.
The Hampton Roads commission, the AP said, uses design details meant to prevent maintenance problems that can arise when porous sections clog. The lot includes a stamped, grooved concrete border so that when runoff moves from traditional concrete to porous concrete, sediment gets trapped instead of clogging up systems and requiring maintenance. Bioswales and rain gardens—long channels of plants and recessed planting areas—also filter pollutants before stormwater reaches streams or sewers, the AP reported.
Other examples in the AP report include the City of New Orleans, which has required permeable paving where practical, and efforts in Indianapolis that included rain gardens at the Newfields museum and recycled plastic grid pavers for an overflow parking lot. Jonathan Wright, director of the garden at Newfields, said, “It has worked really well for us because we don’t park on that lot every single day,” adding that he asked why it should be “asphalt and not breathing and not permeable when you only need to use it 10% of the time?”
Cost and durability questions also figure prominently in the AP reporting. Sunderland said that while alternative materials can cost more up front, owners can gain additional lifetime value from the approach. Asphalt industry representatives, meanwhile, cautioned about tradeoffs and emphasized that pavement designers still need to consider durability for specific traffic and use patterns.
Buzz Powell, technical director at the Asphalt Pavement Alliance, said cities should be cautious about investing in alternatives without understanding how they perform over time. Powell said, “I just think we need to be really, really careful when we put alternative systems in to make sure that we have a good understanding of what the life cycle impact is gonna be,” warning that some options can look good “on paper” but may fail when stress tests—such as heavy vehicles—are applied.
There are also policy changes that indirectly reduce parking-lot heat and runoff. The AP reported that some cities have dropped regulations that require a minimum number of parking spaces for new residential or commercial buildings, with Buffalo, Austin and Minneapolis among those named in the story. Greg Kats, founder of the Smart Surfaces Coalition, said that a single city’s surface changes may not be enough by itself, but that benefits become clearer once cities study them rigorously at scale.
The AP’s broader point is that improving how parking lots are built—or reducing how much pavement they require—can address multiple problems at once, including heat, water quality and related inequities. For local agencies evaluating projects, the central question remains how to combine cooling and runoff benefits with pavement life-cycle performance, while securing funding for retrofits.