LA is replacing 1,600 acres of pavement with plants. Could depaving help the Phoenix heat?

Phoenix is the hottest city in the country. And, we know it’s getting hotter — at least partially due to the urban heat island effect — where all of that concrete that makes up our city traps heat all day — and heats things up even more during the day, as well as at night.

In Phoenix, leaders are trying a lot of things to curb the heat — from our innovative "cool pavement" program — to a campaign to plant trees and create more shade. But, here’s an idea that’s gaining steam: depaving.

It’s pretty much what it sounds like — removing concrete and replacing it with natural vegetation. There have been depaving programs in places like Portland, Oregon; and Chicago spearheaded by nonprofit groups.

But now, Los Angeles County has adopted a depaving plan. They want to remove and replace 1,600 acres of pavement with what our next guest calls “natural infrastructure” over the next 20 years. That’s equivalent to more than 1200 football fields.

Devon Provo is an urban planner and senior manager at Accelerate Resilience L.A., a small nonprofit that works to promote climate resilience. And, in a recent op-ed for The Los Angeles Times, she argues it’s a promising approach for cities looking to adapt to a hotter future. The Show spoke with her more about it.

Full conversation

DEVON PROVO: So at the end of last year, at the end of 2025, Los Angeles County set a depaving target as part of its ongoing sustainability plan. And you're right, their target is to remove 1,600 acres of pavement from schools and public spaces by 2045.

So this is exciting because it marks the first explicit depaving target from a major U.S. public agency, which is really signaling kind of a shift in how policymakers are starting to think about infrastructure and the role of pavement in our built environment.

LAUREN GILGER: Where do you depave? Like, how do you decide where to do this? It's not roads necessarily. We're not going back to dirt roads, but it's other areas, right?

PROVO: Right. Yeah. So of course, pavement is serving essential functions in our cities for mobility and accessibility. So the problem is not pavement everywhere. It's really just the idea that overpaving — putting pavement where we don't truly need it, where it's not truly useful — is blocking out space that could otherwise be used for trees and vegetation.

That is what's becoming kind of a liability for health and resilience concerns. So when we think about depaving, it can be something as small as creating a space in a sidewalk to add a tree well; or taking pavement out of a median that can still function as a median while including vegetation in the middle; or something like a plaza in front of a public building that isn't really serving any real purpose.

GILGER: Interesting. OK, so picking and choosing the places, probably pretty specifically, it sounds like. Let's talk about cost, Devon. You write that concrete seems like the economical choice for some obvious reasons. Natural landscape seems like it might be expensive. But that might not necessarily be the case.

PROVO: Yeah, absolutely. So over time, we really evolved our use of pavement in cities from the initial kind of rollout, which was to make streets and roads more efficient, more easily navigable, which was transformational for commerce and for the usability of our road networks.

But then kind of moving into the 20th century in urban planning, we saw pavement begin to be applied in more and more contexts, using it to suppress weeds or cover up contaminated soil instead of having to clean it. And so now we're kind of starting to see that while that seemed cost effective at the time, we may have actually just kicked the cost down the road.

And so today we're seeing that this overproliferation of pavement is causing costly side effects that cities are still paying for, just in the form of emergency response or disaster recovery and some pretty severe public health impacts.

Devon Provo

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GILGER: Right. So there's heat, there's also flooding, things like that that pavement can be kind of challenging in.

PROVO: Absolutely. Yep. And it's also contributing to prolonged droughts here in Los Angeles. There is a common misconception that LA is a desert, but it's not. It's actually a Mediterranean climate zone. But the way that we've designed the built environment here in Los Angeles has contributed to aridification and this heat island effect, which in turn dries things out.

So it's starting to feel more and more like a desert because of the design choices that we've made. But we can choose to undo those choices and bring back some of the greenery and vegetation that help regulate our temperature and filter the air and manage our stormwater.

GILGER: Yeah. So let me ask you about the broader picture here, because this is something that you mentioned a few U.S. cities have done. It seems like an idea that's out there, the idea that cities might depave and that might be something useful in a climate change future in which we're watching things get hotter, in which the urban heat island effect — like it is here in Phoenix — is making things hotter. How big of a conversation is this?

PROVO: Yeah, this is really taking off globally in kind of the urban planning sphere. So even countries like Belgium and France are starting to invest in pavement removal. The Netherlands launched a national competition a few years back to see which city could remove the most pavement.

And it became kind of a playful competition among residents and cities competing against each other. So there are exciting examples that we can look to to see the scope of what's possible.

GILGER: Yeah. So a city like LA, similarly to a city like Phoenix — maybe even more extreme here in Phoenix where we see these kinds of extreme temperatures more often — how much can you benefit from something like this? Is this, in your mind, part of a broader scheme in which cities should rethink the way that they're built and the way that we use our environments?

PROVO: Yeah, ultimately urban environments really require a balance of both kind of built hardscape surfaces and the living systems like trees and vegetation. We do see through the research that replacing pavement with trees and vegetation can help reduce instances of heat related illness, cardiovascular and respiratory illness, and also improve overall mental well-being.

Here in Los Angeles, we're seeing growing concerns about how hot it is on our schoolyards and the health of children who are exposed to extreme heat at recess. And so pavement removal can be a crucial part of how we kind of adapt to those changes. And we also see that the benefits of nature do tend to increase over time as those plants mature.

So it does require upfront investment to plant those trees and then ongoing stewardship to make sure that they're taken care of, pruned, watered, maintained over time. But that vegetation is really delivering compounding returns in the form of cooler streets and healthier communities. And so it can be a really important part of an overall adaptation strategy for cities to consider.

GILGER: But it sounds like one of many approaches you think maybe cities should be thinking about.

PROVO: Absolutely. It's a portfolio approach. You know, in certain cases, it's not always going to make sense to remove pavement. It may not be possible or appropriate. And so in that case, there can be other strategies that might make more sense, like cool pavement or a shade structure. But certainly we hope that pavement removal can also be part of the conversation as well as thinking about how to reduce the creation of new pavement over time.

So it's one thing to try and remove the pavement that's already there, but it's another to try and be mindful when we design new projects of if we really need to be putting down that much hardscape or if we can design it another way.