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Water: Outreach & Communication

Green Streets: An Interview with Clark Wilson (Transcript)

Host: Jamal Kadri
Smart Growth Team Leader
US Environmental Protection Agency

Guest: Clark Wilson
Urban Designer
US Environmental Protection Agency

Length: 28:06

[Intro music playing]

Jamal Kadri:
Hello, I'm Jamal Kadri with the EPA's Office of Water. Welcome to the first of what we hope will be a regular series that focuses on the intersection of the built environment and water. When the states report to Congress on the condition of their waters, they identify stormwater runoff as one of the biggest threats to clean drinking water. Much of that stormwater runoff comes from roads, which make up nearly a third of our built environment. In this series, we'll be talking to practitioners who can demonstrate how to manage rainwater and snowmelt where it falls in ways that can make for great places, preserve water quality and restore our nation's waterways. Today we're fortunate to have with us Clark Wilson to talk about an alternative to the way we've been building streets in the past, Green Streets, and how they're used for stormwater management. Clark is the senior urban designer with the Smart Growth program at EPA, where he champions the role of good street design in advancing the transportation, livability and environmental goals of smart growth. Clark, welcome. Thanks for joining us on our maiden podcast voyage.

Clark Wilson:
Thanks, Jamal. It's good to be here even though I'm without my usual visual aids.

Jamal Kadri:
Well, I guess, I've seen some of your PowerPoint presentations, and I guess, without those kinds of pictures that speak a thousand words, maybe you can describe for us just what is a Green Sreet.

Clark Wilson:
Okay, well, I guess I'm going to sort of put it back to you to sort of imagine those kind of pleasant streets that you know of in your community, and I'm going to sort of guess that those are pretty pedestrian-friendly?

Jamal Kadri:
The streets that I like best are -- they're walkable, kind of wide sidewalks and a lot of mature trees.

Clark Wilson:
Okay, but they still handle the traffic flow and everything just fine and they provide good access to your house and to places you want to go to and things like that, because that's essentially a Green street. It's a good, functioning street.

Jamal Kadri:
I mean, you sort of describe a little bit about how it feels. How does it function ecologically differently than what we've got?

Clark Wilson:
Okay, well, this is where we can talk about that tree canopy that you were mentioning. And probably the reason why the streets in your neighborhood, and I assume they're quite old, too, is that they have those huge canopy of trees is that the trees themselves were kind of left to grow where they wanted to and not sort of be constrained by a tree-planting pit that's so common now. So, a Green street is, basically, saying, okay, well, let's design a street that allows for as much landscaping as possible, and if you have to put a tree in a pit, let's make that pit have another function. Let's divert stormwater into it, but also, let's just promote a good tree canopy, because the tree canopy has a lot of what we call interception, which just basically means, you know, when the rain falls on it, the leaves pick it up. I would say that on your street, you know, during a light rainfall, there's probably -- no water hits the ground, right?

Jamal Kadri:
On a street like 8th, it's totally covered. There's a total canopy of leaves in the summer.

Clark Wilson:
Right, so that's -- you know, just promoting a good canopy is one of these kind of what I call landscape elements promoted. Or having more impervious surface, more permeable paving, more rain gardens, where the water is diverted off of the street into like a side -- maybe it's a pedestrian bulbouts or something like that. So, it has this sort of not only its social function and its transportation function, but it has this ecological function, where it's actually being responsible for its own runoff.

Jamal Kadri:
Right, and it's taking care of problems that would otherwise be dealt with by some other department, Public Works for stormwater, or CSO Abatement.

Clark Wilson:
Right, and what I often say is a Green street is a street that works with natural conditions and not against it.

Jamal Kadri:
How did you get interested in Green Streets?

Clark Wilson:
Well, my background is in architecture, landscape architecture, city planning and urban design, and I've often thought that streets were the nexus of all these disciplines. But I think my actual sort of "eureka" moment was in my very first landscape architecture studio at UC Berkeley with Professor Louise Mozingo, who told us to design some sort of intervention or design something that's going to protect an urban creek. It was San Leandro Creek in San Leandro, California. And I have to tell you, I don't like getting wet, so I didn't really necessarily want to go down into this stream channel, because it was one of these typical kind of degraded urban stream channels. It's what the hydrologists call -- it was a victim of hydromodification.

Jamal Kadri:
Just the stream being sort of blown out from all the --

Clark Wilson:
They're blown out by all the water rushing into it. And so my team, which was made of Leora Elazar and Keith Lichten, we looked actually outside of the stream channel, and we looked at, well, what's causing all of this erosion into this stream channel and why is it so polluted? And so, when we looked at the neighborhood around it, we saw that it was a low-density, single-family neighborhood, but the streets were seriously like 50 feet wide curb to curb with very low traffic volume. Basically, we were like, hey, why don't we do something in the urban watershed, like something on these streets, and design them in such a way that they're not, you know, blowing out and polluting the channel. So that's where my thesis work kind of stemmed out of that studio, and then it dovetailed very nicely into when I started working as a practitioner for Community Design Architecture in Oakland, California, you know, getting work with putting together the Portland metro Green Streets handbook. It was essentially sort of an extension of my thesis work, and then that led to working on other street-design projects and bringing in this kind of other element of environmental sensitivity to pedestrian friendliness and other aspects that make a Green street.

Jamal Kadri:
I think that's where I first heard you speak, was at a session where you were talking about the opportunity for this notion of regenerative development, of being able to kind of come into an area that's functioning poorly in terms of environmental performance and rebuilding it in a way that it will function better. But I guess it sort of sets up the question -- you sort of alluded to the fact that a lot of the streets we have are wider than they need to be, they've got a lot of impervious surface and they're curb-and-guttered straight to the stream. Why do we have the streets that we have now and what are the other problems that they create that Green Streets might help out with?

Clark Wilson:
Okay, well, this is the point where I point out that there are no villains in this story, really. But a lot of people who built the streets and were dealing with issues of runoff -- and, again, remember that the street is actually -- has two infrastructure systems on top of each other. And this is what people have to realize, too. We have the transportation system and we have the urban drainage system together, okay. And the disciplines that were charged with taking care of this issue were given one problem. The transportation engineers and planners were told to move traffic. The stormwater folks or flood control or whoever were given the charge of moving water, okay. And so they did that effectively but --

Jamal Kadri:
-- as quickly as possible for both disciplines.

Clark Wilson:
Yeah, for both. And so I think we see what happens is that there's then degradation to the social fabric of a neighborhood because streets are so much wider and hard to cross.

Jamal Kadri:
They're designed exclusively for cars in a lot of places.

Clark Wilson:
Right, and not what you would call pedestrian-friendly. But then also, it promoted ecological degradation, like what we talked about before, like San Leandro Creek, you know, just getting blown out and polluted.

Jamal Kadri:
Right, the concern is very localized flooding, and so it's pushing the problem downstream as fast as possible.

Clark Wilson:
Right, and so I'm saying that we have to kind of reframe the problem in front of us, similar to an analogy that I make about seismic codes. Okay, so stick with me on this one. Because, you know, we built buildings a certain way for a period of time, and then an earthquake would happen, and we realized, whoa, the way we built didn't work very well. And so we went out and we changed the codes to address an environmental condition, in this case a very extreme condition such as an earthquake. And so I'm saying that, you know, we reframe where we are right now and say, okay, we built things, we built streets a certain way for decades, and now we have this understanding that, oh, the way we built them --

Jamal Kadri:
-- had these unintended consequences.

Clark Wilson:
-- ain't working so good, you know? It's leading to this social -- and degradation, so, okay, we need to use that knowledge then and change the way we think about building streets and using streets.

Jamal Kadri:
So, I've seen all the sketches that you do, you know, at your desk. Are these Green Streets just something that you dream up or are there places where we can actually go and see them?

Clark Wilson:
Yes, they're all in my imagination. No, Jamal. They do exist, and actually the University of California at Davis, they have a center for sustainable transportation, and the practitioner there, Ellen Greenberg, has been working for a year in putting together a database of examples of what she refers to as sustainable streets. But I would say that they're good examples of Green Streets, and I really hope that we can get that Web address to you as soon as possible, because I know they want to make that all public. But, you know, some good examples right now that you can go visit in Seattle and Portland. The Pacific Northwest, I think, really kind of led the way.

Jamal Kadri:
Why is that?

Clark Wilson:
I think they're dealing with -- in Portland's case, they were dealing with a salmon habitat situation, you know, because they --

Jamal Kadri:
They have an Endangered Species Act charge.

Clark Wilson:
Yeah, and they're -- the Portland metro region is atop a very functioning stream system that has coho salmon and steelhead trout, so they had to do something to protect their waterways that didn't lead to what they call a taking, which basically didn't endanger those species anymore. They had a particular issue that they had to deal with there and it was related to their salmon. So that's what led to them pursuing the Green Streets handbook. But I mean, there are other places than just the Pacific Northwest, too. There's -- you're seeing these things now in -- not things but Green street elements such as rain gardens in the street right away in places like Chattanooga, Kansas City. Chicago is -- Chicago has long been known for beautiful, landscaped streets but not necessarily with that environmental function, but what they're doing now is they have this Green Alleys program, and I would have people just Google that and they can check out what's going on there. Because what they're doing is understanding that alleys make up a lot of impervious surface in their city, and they have a strategy for redesigning them in such a way to be more environmentally friendly.

Jamal Kadri:
You know, a lot of what you're talking about sounds really appealing, but I've got to imagine that when you're replacing this existing infrastructure and adding new tree boxes, a lot of vegetation, different kinds of pervious pavement, it's expensive. Where is the money coming from and what can you tell us about the comparative costs of doing it this way?

Clark Wilson:
Okay, I knew that the cost question -- and cost question always comes up. And I have to preface it by saying that it's a very complex topic, especially when you're talking about comparison -- comparative costs between doing something in a conventional manner and doing something with a green-street strategy, because, as I alluded to earlier, is that there's decades of standardization of the curb-and-gutter street design, you know. And with decades of standardization comes more and more cost-effectiveness. I think you'd agree with that, yeah?

Jamal Kadri:
Sure.

Clark Wilson:
So, when you're taking an approach that then is more specific to the site, more specific to the topography, more specific to the soil conditions of the actual site that the street is, there is more cost involved at the beginning in the design and figuring out, okay, what's --

Jamal Kadri:
You're not designing it on paper and then just laying it down on the site.

Clark Wilson:
Right. You have to say, like, you know, does it make sense to actually have infiltration here because do the cells infiltrate? If they don't, okay, then maybe we have to do something more related to conveyance or storage, or more interception. You know, like there's more of a menu to sort of choose from. So, that itself has a cost issue. And I think that, more and more, if that can be put together as a methodology, and this is what our office has been working on with technical assistance in Delaware and Kentucky, is to actually put together like a handbook and a decision tree of when and where to use certain elements. You know, that's going to help sort of get the cost down because you'll have a methodology. But then, also, what do you think is going to happen to that water after it leaves?

Jamal Kadri:
Well, I guess the real -- yeah, one of the issues is that where the budget used to just be Department of Public Works or Department of Transportation, now you're having cost savings for the folks who would be managing storm water or managing --

Clark Wilson:
Yeah, well I'm saying, okay, well once that water is evacuated off the street, it's polluted. And now with all of these regulations, who's paying for that?

Jamal Kadri:
Right. It's coming out of your sewer bill if you live in a community that's --

Clark Wilson:
Right, because that's what we call the end of pipe treatment. There needs to be some sort of a water treatment plant, you know. If big interceptors -- and what those are are like big huge underground storage that can take the excess run-off when there's a big event. And that costs a lot of money, but right now that's in a different pot from what the street builders have, like the Public Works Department has. So there's really no kind of sharing of cost savings. Do you see what I mean?

Jamal Kadri:
Yeah.

Clark Wilson:
And so that has to be sort of calculated into the overall costs of Green Streets. But I can kind of share with you an anecdote out of Portland, just because the designer there of many other streets has been talking about this for quite some time and has a lot of experience. And on some of the streets that they designed there, it was for very specific problems related to flooding, and so the city had to do a real clean cost comparison of like, well, what is it going to cost for us to sort of upgrade the sewer system, rip up all the pipes, enlarge them. Or what's it going to cost if we just start promoting more infiltration, plant more plants and such? And in that case, the Green Streets approach, the landscape approach actually won out.

Jamal Kadri:
So, how come we aren't seeing more of this? I mean, if the places where it's been tried are successful, people like it, and it has all of these sort of net social benefits, why isn't it more common?

Clark Wilson:
Well, this is a question that myself and my offices are trying to get to the bottom of as well, and we're actually researching this now and looking at the implementation barriers of Green Streets, and then also trying to adjust the issues of costs and sharing costs equitably. But, you know, go back to imagining the street that you live on, okay. And you know, I would basically guess now that if you tried to build that street now, it'd be illegal.

Jamal Kadri:
Right.

Clark Wilson:
And there is just these codes, ordinances, that were, again, back where the transportation engineers were dealing with a particular issue, they came up with a certain set of codes that haven't necessarily been changed even though there's been a lot of public will to change, which is reflected in cities' policies and their comp plans and such. You know, you hear a lot of nice things coming out saying, "Oh, we want all new development to be ecologically sustainable" and such and such and such, which is great. But then when you look at their codes, it's still from like 1950s.

Jamal Kadri:
Yeah, well I think what you're talking about is -- I live on Capitol Hill, but if you ask people where they like to go in the D.C. area, they'll mention Georgetown or Annapolis or places where they have narrow streets, big sidewalks, no set backs, and most municipalities don't let you --

Clark Wilson:
Yeah, more tree canopy, more social spaces, yeah, exactly. So, what I call these is institutional barriers --

Jamal Kadri:
It's not the path of least resistance to do a Green street. I mean, you have to basically change codes and ordinances.

Clark Wilson:
Right, and you've got to get a lot of very different people in a room at the same time, people who aren't necessarily used to talking to each other. And this is what I say when I speak, you know, this is what I'm talking about when I talk about institutional cooperation. You know, get the people out of their silos to start working with one another. And this is also out of the Portland anecdote, too. And they found that there was just tremendous cost savings when they had all the right people talking at the beginning of a project rather than coming in at the end and then having to go back and redesign, what they call the "backtracking," because that's very expensive.

Jamal Kadri:
It sounds like a number of the communities that have tackled this are also municipalities that have been on the hook for probably the most expensive public works investments of their history. I mean, communities like Portland that I think is spending well over a billion dollars on combined sewer overflow abatement. And I think a number of those cities that you names have those kinds of challenges.

Clark Wilson:
Right, yeah. There's the challenge that, yeah -- New York, Los Angeles, San Francisco, Denver, our own Washington, D.C., Philadelphia, Chicago. Yeah, they're coming under both regulatory forces, but then just also, again, from the public, just wanting better streets. And I think that this Green street strategy is really front and center in solving some of those issues.

Jamal Kadri:
So, if there are folks who are listening who are not from San Francisco or Seattle or Portland or Chicago --

Clark Wilson:
Well, even if they are.

Jamal Kadri:
Well, what would you recommend for people about how to look at opportunities for implementing Green Streets where they live?

Clark Wilson:
Okay, well I would go back to this, like reframe the problem and, you know, realize that, okay, you have these storm water regulations that are now coming down in many states. You know the infrastructure is aging. You know that many of your streets can be more and more, you know, I mean, more attractive than just pedestrian-friendly. And let the powers that be or the decision-makers know that this can all kind of be addressed together and looking for these kind of opportunities for getting more of these landscape elements into street design. You can volunteer your street as a pilot project, like they have the SEA Streets in Seattle.

Jamal Kadri:
Street Edge Alternatives.

Clark Wilson:
Street Edge Alternatives, yes. Also, in Portland, you know, they did a few pilot projects of some of these bulbouts that are also rain gardens.

Jamal Kadri:
They're sort of traffic calming, and they took it wide, straight and narrowed it.

Clark Wilson:
Yeah, they narrowed it down. They did, you know, in traffic calming lingo, is a choker. But they made these attractive rainwater gardens. And other communities, or I mean other neighborhoods, saw that and said, "Hey! Those are nice!"

Jamal Kadri:
"We want that."

Clark Wilson:
"We want that!" So, yeah --

Jamal Kadri:
It's a lot more attractive than, say, a speed bump in terms of traffic calming.

Clark Wilson:
It's a lot more attractive than a speed bump. And you know, or take a lead like Chicago does, and as I said before, they said, "Okay, let's start relatively small," quote unquote, small with our alleys and see what we can learn from that and how much of a reduction we can get from that. You know, try that out and really push. And if you're at staff level and wanting to affect some change in whatever institution you are, really push this institutional cooperation that I'm talking about. Get the director of planning into the room with the director of public works, with the director of the public utilities company.

Jamal Kadri:
In Chicago, I think it's coming from the mayor.

Clark Wilson:
Yeah, and so get the top brass there talking about this. And then also, make sure that you bring along the actual builders of the street and the people who are maintaining the street, too, just so that they know why things are being done a certain way and so that they're brought on board, too, so that you don't get resistance down the line saying, "Well, nobody told us how to maintain the street" and such. So, that also comes up from the Portland history.

Jamal Kadri:
Yeah, it is -- it sounds like a really great opportunity. One of the figures that I've heard kicked around is that half of everything we've built since European settlement in this country was built since 1950, and if a third of it is streets, then that's a lot of space that, right now, is responsible for a lot of the storm water problems that we have, but it's publicly owned. It needs to be rebuilt, and we've got a lot of opportunities to do it.

Clark Wilson:
And that's exactly it, just look at it as an opportunity.

Jamal Kadri:
Well, we'll look to be able to send some folks to some Web sites so it will give you some idea of what Green Streets look like and have more information. Thanks for helping us kick off our podcast series.

Clark Wilson:
Well, thanks for having me.

Jamal Kadri:
And thanks to all you who are joining us. We have a tentative title for this series. We're thinking about calling it "From Gray Funnels to Green Sponges." And you can send us an email and let us know what you think of that name or suggest another. You can email me at kadri.jamal@epa.gov. That's k-a-d-r-i-.-j-a-m-a-l @ e-p-a-.-g-o-v, or for more information about this program or about Green Streets, please visit our Web page. It's epa.gov/owow/podcasts. Until next time, remember, keep it where it falls.

[Outro music playing]


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