Water Permeable Driveways

Water Permeable Driveways

Part of Ep. 1905 Water Conservation

An important way to conserve water and to protect our lakes and streams is to reduce storm water run-off.  Concrete and asphalt driveways are one of the biggest culprits.   A new solution is water permeable concrete.  We’ll look at three different kinds of eco-driveways that reduce water run-off.

Premiere date: Jul 06, 2011

TRANSCRIPT+
Wisc Gardener Transcript: 

Shelley Ryan:

There are many ways to conserve water in the garden and back yard. Use rain barrels, plant a gravel garden. Well, now we're going to focus on conserving water on the driveway. I'm with John Gishnock of Evansville of the company Formacology. This has become one of your specialties. Explain to me though, first of all, why it's so important.

John Gishnock:

Yes, at the residential scale and small commercial scale we generate a lot of rainwater.

 

Shelley Ryan:

Yes, we do.

 

John Gishnock:

If we think about every rain drop that hits the ground, it has got to go somewhere our roofs, our driveways, and sidewalks really generate a lot of water.

 

Shelley Ryan:

It all goes downhill into the streams.

 

John Gishnock:

You bet, where it usually causes more harm than good. Now we're asking our driveways to help be a water conservationist too and actually help soak up some water. Next to our roof areas, driveways are really the second largest impervious surface at the residential scale.

 

Shelley Ryan:

I guess that makes sense, yeah.

 

John Gishnock:

They generate quite a bit of water themselves.

 

Shelley Ryan:

You have some methods of dealing with this?

 

John Gishnock:

Yes, we've got three ways to deal with it. Materials that actually deal with water as it hits the driveway, driveways that divert water into water saving features, and we actually are reducing the footprints of driveways just altogether in designing smaller driveways.

 

Shelley Ryan:

Well, let's start with this one, because to me it looks like a whole heck of a lot of concrete.

 

John Gishnock:

You bet. But this is a different type of concrete. This concrete is hard like most concretes but looks like a sponge. This driveway, as water hits it, actually is allowed to soak through the concrete and into the ground.

 

Shelley Ryan:

So it's porous?

 

John Gishnock:

You bet.

Shelley Ryan:

Okay, stop right there, I've got to test this. I just happen to have a hose. I won't get you wet, I promise.

 

John Gishnock:

So, as you can see, five inches of porous concrete mixed with the washed gravel underneath, is taking that water straight through and back down into the ground where we want it.

 

Shelley Ryan:

It's just vanishing. You're right. It's soaking right in like a sponge.

 

John Gishnock:

Yes.

 

Shelley Ryan:

Wow, so there's no runoff at all?

 

John Gishnock:

There's no runoff at all here.

 

Shelley Ryan:

So what happens in the wintertime? I would assume it would be better then.

 

John Gishnock:

Good question. You actually see a lot less icing on a system like this because of the air flow transfer between the ground. Air moving through the pores actually helps alleviate some of the icing that's on it. So our clients aren't using salt or sand on these types of driveways.

 

Shelley Ryan:

And less salt is also good for our water.

 

John Gishnock:

Yes, yes, good point.

 

Shelley Ryan:

Is there a place where you would not use one of these?

 

John Gishnock:

I think probably a shady site, sites with lots of trees. As you can imagine, we want to keep the pores open because that's really the most functioning part of these driveways. Leaves, sticks and debris could get in and clog the pores so these work better at open sites.

 

Shelley Ryan:

Full sun like this.

 

John Gishnock:

Yes, yes.

 

Shelley Ryan:

So then, your other methods, would we use one of those in a more shady site?

 

John Gishnock:

You bet. Diverting water to a rain garden, we can actually re-slope a driveway. We could use traditional materials like concrete or asphalt, but rather than having those driveways slope towards the road--

 

Shelley Ryan:

Or my front door!

 

John Gishnock:

Yes, or your front door, we can have them slope back towards a rain garden, where deep-rooted native plants are actually going to soak that water up.

 

Shelley Ryan:

So it's not going down into the streams and the lakes, or my front door. It's going into the landscape and staying there.

 

John Gishnock:

Yes, and becoming an asset in some ways, a beautiful garden.

 

Shelley Ryan:

Sure, and you don't have to water it usually either.

 

John Gishnock:

Yes, good point. Reducing the driveways, the width, the overall size of them is a great way so using the old-fashioned concrete tread driveways that were kind of a big hit in the '50s have really made a comeback.

 

Shelley Ryan:

You mean like the narrow strips of concrete?

 

John Gishnock:

Yes, exactly.

 

Shelley Ryan:

Oh, okay.

 

John Gishnock:

We can just reduce the size of driveways by 40-50% just using the concrete treads.

 

Shelley Ryan:

Then what do you have in between those though? Is that just lawn?

 

John Gishnock:

Well, it can be. If you maybe get off the driveway a little bit, you could use a paver. Sometimes we have these honeycomb pavers that you could actually grow lawn up through. So, coupled with the concrete driveways, we have kind of a visually less invasive driveway too.

 

Shelley Ryan:

Well, other than the sun/shade issue, I assume budget is one thing. How else do I decide as a homeowner which one's the best for me?

 

John Gishnock:

Yeah, good question. I think budget is probably the biggest concern. There a wide variety of materials, and we always like to suggest to homeowners to think about their budget in total and kind of factor the driveway in as one other element. Develop your budget for your driveway and then work through the different materials together. Some of these driveways need and can be built by experts, but the concrete driveway, for instance, the concrete tread driveway, if you work with a local contractor, you could certainly install portions of that yourself.

 

Shelley Ryan:

So you could save money that way, do a little yourself.

 

John Gishnock:

You bet.

 

Shelley Ryan:

We'll have more information about all of this on our Website, so thank you very much, John.

 

John Gishnock:

Great, thank you, Shelley.

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